2004 Chevrolet $10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma SPECIFICATIONS FAST! ER TIGHTENING SPECIFICA’ Fastener Tightening Specifica Specification Application Metric English Accelerator Control Cable and Cruise Control Cable Bracket Nut 9Nm coe Accelerator Control Cable Bracket Nut 12Nm 106 Ib in Accelerator Control Cable Bracket Stud to Intake a 53 ibin Manifold ‘Accelerator Control Cable Bracket Stud to - Throttle Bod 12N.m 106 Ib in Air Cleaner Adapter Stud 10 Nm 39 Ib in Air Cleaner Outlet Duct Hose Clamp 4Nm 32 [bin Air Cleaner Outlet Duct Wingnut 2Nm 18 Ib in Balance Shaft Driven Gear Bolt « First Pass 20 N.m 15 Ib ft ¢ Final Pass 35 degrees Balance Shaft Retainer Bolt 12Nm 106 Ib in Battery Negative Cable Bolt to Engine 17Nam BIbft Belt Idler Pulley Bolt 50 N.m 37 Ib ft Camshaft Retainer Bolt Nm 106 Ib in Camshaft Sprocket Bolt 25 Nm 18 Ib ft Connecting Rod Nut First Pass 27Nm 20 Ib ft « Final Pass 70 degrees Crankshaft Balancer Bolt 95. N.m 70 Ib ft Crankshaft Balancer Remover/Installer Bolt 25 Nm 18 Ib ft Crankshaft Bearing Cap Bolt - Preferred Method First Pass 20 Nm 15 Ib ft « Final Pass 73 degrees Crankshaft Bearing Cap Bolt - Optional Strategy 105 N.m 77 Ib ft Crankshaft Position Sensor Bolt 9Nm 80 Ib in2004 Chevrolet $10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Crankshaft Pulley Bolt 58 N.m 43 Ib ft Crankshaft Rear Oil Seal Housing Bolt and Nut Nm 106 Ib in Crankshaft Rear Oil Seal Housing Retainer Stud 6Nm 53 [bin Cylinder Head Bolt - Preferred Method ¢ All Bolts First Pass in Sequence 30. Nm 2 Ib ft Long Bolt Final Pass in Sequence 75 degrees ¢ Medium Bolt Final Pass in Sequence 65 degrees Short Bolt Final Pass in Sequence 55 degrees Cylinder Head Bolt - Optional On-Vehicle Strateg ¢ First Pass in Sequence 35.N.m 26 Ib ft # Second Pass in Sequence 60 Nm 44 Ib ft e Final Pass in Sequence 90 N.m 66 Ib ft Cylinder Head Core Hole Plug 20 Nm 15 Ib ft Distributor Cap Bolt 24Nm 21 Ib in Distributor Clamp Bolt 25 Nm 18 Ib ft Drive Belt Idler Pulley Bolt 50 Nm 37 Ib ft Drive Belt Tensioner Bolt 30 N.m 37 Ib ft Engine Block Coolant Drain Hole Plug 20 Nm 15 Ib ft Engine Block Left Rear Oil Gallery Plug 30N.m 22 Ib ft Engine Block Left Side Oil Gallery Plug 20 N.m 15 Ib ft Engine Block Oil Gallery Plug 20N.m 15 Ib ft Engine Block Right Rear Oil Gallery Plug 20 N.m 15 Ib ft Engine Coolant Heater Bolt/Screw 2Nm 18 Ib in Engine Coolant Temperature (ECT) Sensor 20Nm 15 Ib ft Engine Coolant Temperature Gage Sensor 20 Nm 15 Ib fi Engine Flywheel Bolt 100 N.m 74 Ib ft Engine Front Cover Bolt Nm 106 Ib in Engine Lift Bracket Bolt 15 Nm IIb ft Engine Lift Front Bracket Stud 35. Nm 26 Ib ft Engine Mount Bolt - Through-bolt 74N.m 35 Ib ft Engine Mount Bolt to Engine 34N.m 40 Ib ft Engine Mount Bracket Bolt to Frame 45 Nm 33 Ib ft Engine Mount Nut - Through-bolt 63 Nm 46 Ib ft Engine Oil Cooler Pipe Clip Bolt to Oil Pan 9Nm 80 Ib in Engine Oil Level Sensor BNm 115 Ib in Engine Oil Pressure Gage Sensor 30 N.m 22 Ib ft Envine Oil Pressure Gave Sensor Fitting - Plus2004 Chevrolet $10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Required Angle 15.Nm IIb ft Engine Wiring Hamess Bracket Bolt to Generator], and Drive Belt Tensioner Bracket a es Engine Wiring Hamess Bracket Bolt to Rear of ssNm sen Cylinder Head Engine Wiring Harness Bracket Nut to Intake DNm we Manifold Evaporative Emission (EVAP) Canister Purge Solenoid Valve Nut to Intake Manifold HOEY ee Exhaust Manifold Bolt/Stud « First Pass 5Nm Tibi Final Pass 30Nm Dibht Fan and Water Pump Pulley Bolt 25 Nm Is ibht Fuel Meter Body Bracket Bolt 10 Nm 89 Ib in Fuel Pipe Bracket Bolt 6Nm 33 1b in Fuel Pipe Bracket Bolt to Rear of Cylinder Head |__30 Nm Dib fe Fuel Pipe Retainer Nut 3Nm 27 Ib in Fuel Supply Pipe Nut - Fuel Tank Side 30Nm DIbfe Generator and Drive Belt Tensioner Bracket Bolt] 419 m an to Engine Generator and Drive Bel Tensioner Bracket Stud] 41 xy coA Generator and Drive Belt Tensioner Bracket Stud] 59 x) en to Engine Ground Wire or Strap Bolt to Rear of Cylinder a seA Head Heater Inlet Hose Fitting 25 Nm isib fh Tgnition Coil Stud DNm 106 Ib in Knock Sensor 25 Nm 18 Ib ft Lower Intake Manifold Bolt « First Pass in Sequence 3.Nan 27 Ib in « Second Pass in Sequence 12Nm 106 tb in « Final Pass in Sequence i5Nm ILib Oil Filter 30Nm Dib Oil Filter Adapter Bolt 2 Nm Sibi Oil Filter Fitting 35m 26 1b fe Oil Level Indicator Tube Bolt Nm 106 Ib in Oil Pan Baffle Bolt 12Nm 106 1b in2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Oil Pan Bolt and Nut in Sequence 25 Nm 18 Ib ft Oil Pan Drain Plug 25 Nm 18 Ib ft Oil Pump Bolt to Rear Crankshaft Bearing Cap 90 Nm 6o1b ft Oil Pump Cover Bolt DN 106 Ib in Power Steering Fluid Reservoir Filler Neck Bolt |, to Power Steering Pump Bracket aon 15 Ib ft Power Steering Pump Bolt 50 Nm 371bR Power Steering Pump Bracket Bolt to Engine 41Nm 30 Ib ft Power Steering Pump Bracket Stud Nut 41Nm 30 1b ft Power Steering Pump Bracket Stud to Engine 20Nm 1S Ib tt Power Steering Pump Nut to Engine 41Nm 30Ib ft Power Steering Pump Rear Bracket Nut to Nm ane Engine Stud Power Steering Pump Rear Bracket Nut to Power 50 Nam 37 Ib ft Steering Pump Radiator Inlet Hose Support Bracket Nut to Exhaust Manifold Stud ceo eee Remote Oil Filter Adapter Mounting Bracket Bolt| 30N.m 22 Ib ft Remote Oil Filter Adapter Nut 25.Nm 18 Ib tt Remote Oil Filter Inlet and Outlet Hose Clip Bolt| 10 Nm 89 Ib in Remote Oil Filter Inlet and Outlet Hose to Remote Oil Filter Adapter Bolt 35Nm 26 Ib ft Remote Oil Filter Inlet and Outlet Hose to ; Remote Oil Filter Pipe Adapter Bolt aoe eel ey Remote Oil Filter Pipe Clip Bolt to Oil Pan oNm 80 1b in Secondary Air Injection (AIR) Check Valve Pipe | 49 14 m So Ib Bracket Bolt to Engine Secondary Air Injection (AIR) Check Valve Pipe | 55 x, A Stud Nut Secondary Air Injection (AIR) Reactor Pipe Nm WA Bracket Nut Spark Plug « Initial Installation - NEW Cylinder Head 30 Nm Dib fe «All Subsequent Installations 15Nm lib Spark Plug Wire Support Bolt DNm 106 Ib in Starter Motor Wiring Harness/Transmission 5 Cooler Pipe Bracket Bolt to Oil Pan omy SoD in Throttle Body Stud oNm 80 1b in Transmission Bolt to Oil Pan a7Nm 33 Ib ft2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Transmission Cover Bolt 12Nm 106 Ib in Upper Intake Manifold Stud e First Pass SNm 44 Ib in Final Pass 9Nm 80 Ib in Valve Lifter Pushrod Guide Bolt 16 N.m 12 Ib ft Valve Rocker Arm Bolt 30 N.m 22 Ib ft Valve Rocker Arm Cover Bolt 12Nm 106 Ib in Water Outlet Stud 25N.m 18 Ib ft Water Pump Bolt 45 N.m. 33 Ib ft ENGINE MECHANICAL SPECIFICATIONS Engine Mechanical Specifications Application Metric English General « Engine Type 90 degree V6 « Displacement 43L 262 CID « RPO LU3 e VIN x e Bore 101.60 mm 4.012 in Stroke 88.39 mm 3.480 in « Compression Ratio 92:1 « Firing Order 1-6-5-4-3-2 Spark Plug Gap 1.52 mm 0.060 in Balance Shaft Bearing Journal Diameter - Rear _ O88 100 1.4994-1.500 in « Bushing Bore Diameter - Rear 0.050-0.088 mm | 0.0020-0.0035 in Block * Crankshaft Main Bearing Bore Out-of- 0,050 mm 0.002 in Round « Cylinder Bore Diameter = o18-101 cs 4.0007-4.0017 in « Cylinder Bore Out-of-Round - Production 0.017 mm 0.0007 in2004 Chevrolet $10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma * Cylinder Bore Out-of-Round - Service 0.05 mm 0.002 in © Cylinder Bore Taper - Production Relief eee Onan Side * Cylinder Bore Taper - Production Thrust 0.012 mm 0.0005 in Side « Cylinder Bore Taper - Service 0.025 mm 0.0010 in # Cylinder Head Deck Surface Flatness 0.050-0.152 mm 0.002-0.006 in Camshaft + Camshaft End Play 0.0254-0.2286 0.0010-0.0090 in cn ATA : « Camshaft Journal Diameter ATAU ATAO | 1 $677-1.8696 in + Camshaft Journal Out-of-Round 0.025 mm 0.001 in + Camshaft Lobe Lift - Exhaust 720-730 mm | 0283-0287 in « Camshaft Lobe Lift - Intake 6.97-7.07 mm 0.274-0.278 in « Camshaft Runout 0.065 mm 0.0026 in Connecting Rod « Connecting Rod Bearing Clearance - Production’ 0.038-0.078 mm 0.0015-0.0031 in * Connecting Rod Bearing Clearance - Service 0.025-0.063 mm 0.0010-0.0025 in « Connecting Rod Side Clearance 0.15-0.44 mm 0.006-0.017 in Crankshaft * Connecting Rod Journal Diameter 57.116-57.148 2.2487-2.2497 in mm « Connecting Rod Journal Out-of-Round - 0.008 mm 0.0003 in Production : « Connecting Rod Journal Out-of-Round - 0.025 mm 0.0010 in Service « Connecting Rod Journal Taper - Production} 0.010 mm 0.0004 in + Connecting Rod Journal Taper - Service 0.025 mm 0.0010 in # Crankshaft End Play 0.050-0.20 mm 0,002-0.008 in ¢ Crankshaft Main Bearing Clearance #1 - Production 0.02-0.05 mm 0.0008-0.0020 in + Crankshaft Main Bearing Clearance #2, #3, and #4 - Production 0.028-0.058 mm 0.001 1-0.0023 in2004 Chevrolet $10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma « Crankshaft Main Bearing Clearance #1 - Service 0.0254-0.05 mm 0.0010-0.0020 in + Crankshaft Main Bearing Clearance #2, #3, and #4 - Service 0,025-0,063 mm 0.0010-0.0025 in Crankshaft Main Journal Diameter #1 62.199-62.217 2.4488-2.4495 in mm . at Main Journal Diameter #2 and | 62. 9h 62 215 | 5 44g5-9.4494 in ¢ Crankshaft Main Journal Diameter #4 62,179-62.203 mm 2.4480-2.4489 in ¢ Crankshaft Main Journal Out-of-Round - eas 0.005 mm 0.0002 in . cman Main Journal Out-of-Round - ee ary # Crankshaft Main Journal Taper 0.007 mm, 0.0003 in Exhaust Manifold « Surface Flatness - Flange to Flange 0.25 mm 0.010 in # Surface Flatness - Individual Flange 0.05 mm 0.002 in Intake Manifold # Surface Flatness 0.10 mm 0.004 in Lubrication System # Oil Capacity for C/K, G/H with Filter 43L 45 qt # Oil Capacity for C/K, G/H without Filter 3.8L 4at # Oil Capacity for S/T, MIL with Filter 47L Sqt « Oil Capacity for S/T, M/L without Filter 43L 45 qt # Oil Pressure - at 1,000 RPM 42 kPa 6 psi # Oil Pressure - at 2,000 RPM 125 kPa 18 psi # Oil Pressure - at 4,000 RPM 166 kPa 24 psi Piston Rings * Piston Ring End Gap - First Compression Ring - Production 0.25-0.40 mm 0.010-0.016 in « Piston Ring End Gap - Second Compression Ring - Production 0.38-0.58 mm 0.015-0.023 in « Piston Ring End Gap - Oil Control Ring - Production’ 0.25-0.76 mm 0.010-0.029 in2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma * Piston Ring End Gap - First Compression Ring - Service 0.25-0.50 mm 0.010-0.020 in + Piston Ring End Gap - Second Compression Ring - Service 0.38-0.80 mm 0.015-0.031 in « Piston Ring End Gap - Oil Control Ring - Service 0.005-0.090 mm 0.0002-0.0035 in Piston Ring to Groove Clearance - First Compression Ring - Production 0.030-0.070 mm 0.0012-0.0027 in Piston Ring to Groove Clearance - Second Compression Ring - Production 0.076-0.280 mm 0.0030-0.0110 in Piston Ring to Groove Clearance - Oil Control Ring - Production 0.046-0.196 mm 0.0018-0.0077 in Piston Ring to Groove Clearance - First Compression Ring - Service 0.030-0.085 mm 0.0012-0.0033 in # Piston Ring to Groove Clearance - Second Compression Ring - Service 0,030-0,085 mm 0.0012-0.0033 in « Piston Ring to Groove Clearance - Oil Control Ring - Service 0.076-0.200 mm 0.0030-0.0079 in Pistons and Pins Piston - Piston to Bore Clearance - Production 0.018-0.061 mm 0.0007-0.0024 in « Piston - Piston to Bore Clearance - Service 0.075 mm 0.0029 in # Pin - Piston Pin Clearance to Connecting Rod Bore - Press Fit 0.012-0.048 mm 0.0005-0.0019 in « Pin - Piston Pin Clearance to Piston Pin Bore - Production 0.013-0.023 mm 0.0005-0.0009 in Pin - Piston Pin Clearance to Piston Pin Bore - Service 0.025 mm 0.0010 in Pin - Piston Pin Diameter 23,545-23.548 0.9270-0.9271 in mm Valve System # Valves - Valve Face Angle 45 degrees + Valves - Valve Seat Angle 46 degrees * Valves - Valve Seat Runout 0.05 mm 0.002 in + Valves - Valve Seat Width - Intake 1,016-1.651 mm | 0.040-0.065 in Valves - Valve Seat Width - Exhaust 1,651-2.489 mm 0.065-0.098 in2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma « Valves - Valve Stem Oil Seal Installed 1-2 mm 0.03937-0.07874 Height in # Valves - Valve Stem-to-Guide Clearance - | 9 995.0069 mm | 0,0010-0.0027 in Intake - Production « Valves - Valve Stem-to-Guide Clearance - | 9 995.0,094 mm | 0.0010-0.0037 in Intake - Service * Valves - Valve Stem-to-Guide Clearance - | 9 935.0.69 mm | 0.0010-0.0027 in Exhaust - Production ~ - © Valves - Valve Stem-to-Guide Clearance - | 9 995-0.994 mm | 0.0010-0.0037 in Exhaust - Service _ : # Rocker Arms - Valve Rocker Arm Ratio 151 « Valve Springs - Valve Spring Free Length 51.3 mm 2.02 in * Valve Springs - Valve Spring Installed eat een lietesceionne Height - Intake « Valve Springs - Valve Spring Installed 42.92-43.43 mm | 1.670-1.700 in Height - Exhaust ° : Valve Springs - Valve Spring Load - 338-374 N@_| 76-84 Ib @ 1.70 Closed 43.2 mm in 832-903 N @ 187-203 lb @ # Valve Springs - Valve Spring Load - Open | »°33°3 mm ea SEALERS, ADHESIVES, AND LUBRICANTS Sealers, Adhesives, and Lubricants GM Part Number United Application Type of Material | _ States Canada Air Cleaner Outlet at MAF Sensor Lubricant 12345884 | 5728223 Balancer Shaft Driven Gear Bolt Threadlock 12345382 | 10953489 Camshaft Retainer Bolt Threadlock 12345382 | 10953489 Crankshaft Balancer Keyway Adhesive 12346141 | 10953433 Cylinder Head Bolt Sealant 12346004 | 10953480 Engine Block to the Crankshaft Rear Oil Seal Housing Junction at the Oil Adhesive 12346141 | 10953433 Pan Sealing Surfaces Engine Block to the Engine Front Cover Junction at the Oil Pan Sealing Adhesive 12346141 | 10953433 Surfaces Envine Block at the Lower Intake2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Manifold Sealing Surfaces Adhesive | 12346141 | 10953433 Engine Block Coolant Drain Hole Plug| Sealant 12346004 | 10953480 Engine Block Core Hole Plug Threadlock | 12345382 | 10953489 Engine Block Oil Gallery Plug Sealant 12346004 | 10953480 Engine Coolant Temperature (ECT) Sealant 19346004 | 10953480 Gage Sensor Engine Coolant Temperature ECT) —— eg eee sensor Engine Oil SAE 5W-30 Oil | 12343610 | 993193 Engine Oil Pressure Sensor Sealant 12346004 | 10953480 Engine Oil Pressure Sensor Fitting Sealant 12346004 | 10953480 Engine Oil Supplement Lubricant 1052367 | 992367 Evaporative Emission (EVAP 3453 3 Canster Purge Le Ne) stud Threadlock 12345382 | 10953489 Exhaust Manifold Bolt/Stud Threadlock | 12345493 | 10953488 Expansion Cup Plug - Balance Shaft a pomsreneeny | pene Rear Bearing Hole Expansion Cup Plug - Camshaft Rear Sealant 12346004 | 10953480 Bearing Hole Fuel Meter Body Bracket Bolt Threadiock | 12345382 | 10953489 Fuel Pipe Bolt Threadlock | 12345382 | 10953489 Lower Intake Manifold Bolt Threadlock | 12345382 | 10953489 Oil Level Indicator Tube Sealant 12346004 | 10953480 Oil Pump Sereen Tube Sealant 12346004 | 10953480 Throttle Body Stud Threadlock | 12345382 | 10953489 Upper Intake Manifold Stud Threadlock | 12345382 | 10953489 Valve Train Component Prelube Lubricant | 12345501 | 992704 Water Pump Bolt Sealant 12346004 | 10953480 COMPONENT LOCATOR DISASSEMBLED VIEWS2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 508 1: Upper and Lower Intake Manifold View Courtesy of GENERAL MOTORS CORP. Callouts For Fig. 1 Callout Component Name 307 Thermostat 308 Thermostat Seal 309a Thermostat Housing - S/T/C/K. 309b Thermostat Housing - M/L/G/H 310 Thermostat Housing Stud 503 Lower Intake Manifold 504 Fuel Meter Body 505 PVC Valve Cover Seal 506 PVC Valve Cover 507 Wire Harness Bracket 508 Wire Harness Bracket Nut2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 509 Fuel Pipe Bolt 310 Fuel Pipe Nut an Fuel Pipe Seal Retainer 512 Upper Fuel Pipe Seal 313 Fuel Pipe Spacer 514 Lower Fuel Pipe Seal 315 Throttle Body Gasket 516 Throttle Body 317 Throttle Body Stud 518 Upper Intake Manifold Stud 519) Fuel Meter Body Seal 533 Upper Intake Manifold 534) Upper Intake Manifold Gasket 700 Fuel Pipes 701 Throttle Position (TP) Sensor Bolt 702 Throttle Position Sensor 703 Idle Air Control (IAC) Sensor Bolt 704 Idle Air Control Sensor 705 Idle Air Control Sensor Seal 7332004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma F 2: Upper Engine View 1 Courtesy of GENERAL MOTORS CORP. Callouts For Fig. 2 Callout Component Name 500 Intake Manifold Assembly 501 Lower Intake Manifold Gasket 502 Lower Intake Manifold Bolt 710 Ignition Coil Wire 71 Evaporative Emission (EVAP) Purge Valve Hose 712 Evaporative Emission (EVAP) Purge Valve Bolt 713 Evaporative Emission (EVAP) Purge Valve 714 MAP Sensor 715 Evaporative Emission (EVAP) Purge Valve Seal 716 MAP Sensor Seal 117 Ignition Coil Module Bolt 718 Ignition Coil Module 719 Ignition Coil Bolt 720 Ignition Coil 721 Throttle Cable Bracket Nut 722 Throttle Cable Bracket 723 Throttle Cable Bracket Bolt 724 Throttle Cable Bracket Stud 725 Ignition Wire Harness - Right 726 Ignition Wire Harness Retainer 727 Ignition Wire Harness Retainer 728 Ignition Wire Harness Retainer 729 Distributor Bolt 730 Distributor 731 Ignition Wire Harness - Left 732 Ignition Wire Harness Retainer 733 Ignition Wire Harness Retainer 734 Ignition Wire Harness Retainer 735 Distributor Gasket 740 Spark Plug2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma M16 4t7, 736 6, air asst So ; a oS var a 10 «150M a LH sav = a* ral, a 148, a F529 La) s¥ eee 3: Upper Engine View 2 Courtesy of GENERAL MOTORS CORP. Callouts For Fig. 3 Callout ‘Component Name 200 Cylinder Head 201 Valve Lifter 202 Valve Pushrod 203 Valve Lifter Retainer Bolt 204 Valve Lifter Retainer 205 Valve Stem Oil Seal 206 Valve Spring 207 Valve Spring Cap 208 Valve Spring Key 209 Valve Rocker Arm Support 210 Valve Rocker Arm2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 2u1 Valve Rocker Arm Bolt 212 Cylinder Head Bolt - Long 213 Cylinder Head Bolt - Medium 214 Cylinder Head Bolt - Short 215 Valve 216 Cylinder Head Gasket 217 Cylinder Head Locating Pin 414 Oil Fill Tube Grommet 415 Oil Fill Tube - G/H 415 Oil Fill Tube - S/T 415 Oil Fill Tube - M/L 415 Oil Fill Tube - C/K 416 Oil Fill Cap Seal 416 Oil Fill Cap Seal 416 Oil Fill Cap Seal 416 Oil Fill Cap Seal 417 Oil Fill Cap 417 Oil Fill Cap 417 Oil Fill Cap 417 Oil Fill Cap #21 Oil Fill Tube Seal 421 Oil Fill Tube Seal 523 Valve Rocker Arm Cover Bolt 524 Valve Rocker Arm Cover Bolt Grommet 525 Valve Rocker Arm Cover - Left 526 Valve Rocker Arm Cover Gasket 527 PCV Valve Grommet 528 Valve Rocker Arm Cover - Right 529 Fresh Air Tube Grommet 600 Exhaust Manifold 601 Exhaust Manifold Gasket - Large 602 Exhaust Manifold Gasket - Small 603 Exhaust Manifold Heat Shield 604 Exhaust Manifold Heat Shield Bolt 605 Spark Plug Wire Heat Shield - Large 606 Exhaust Manifold Bolt 607 Exhaust Manifold Stud Spark Plug Wire Heat Shield - Small 6082004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma PCV Hose 737 PCY Valve 7238 Ignition Wire Bracket 29 Ignition Wire Bracket Bolt 741 Engine Coolant Temperature Sensor 748 Fresh Air Tube Fig. 4: Lower Engine View 1 Courtesy of GENERAL MOTORS CORP. Callouts For Fig. 4 Callout Component Name 100 Engine Block 116 Balance Shaft Bearing - Rear 117 Camshaft Bearing 118 Balance Shaft2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 119 Balance Shaft Bearing - Front 121 Balance Shaft Retainer Plate 122 Balance Shaft Retainer Plate Bolt 123, Balance Shaft Driven Gear 124 Balance Shaft Driven Gear Bolt 125 Connecting Rod Nut 126 Connecting Rod Cap 127 Connecting Rod Bearing 128 Connecting Rod 129 Connecting Rod Bolt 130 Piston Pin 131 Piston 132 Piston Ring Set 144 Front Oil Gallery Plug - Left 145 Front Oil Gallery Plug - Right 146 Side Oil Gallery Plug - Left 147 Engine Block Coolant Drain Plug - Left 148 Engine Block Core Plug 151 Balance Shaft Rear Bearing Hole Plug 152 Camshaft Rear Bearing Hole Plug 153 Rear Oil Gallery Plug - Left 154 Transmission Locating Pin 155 Rear Oil Gallery Plug - Right 217 Cylinder Head Locating Pin 218 Camshaft 219) Camshaft Retainer Plate 220 Camshaft Retaining Plate Bolt 21 Camshaft Drive Gear Locating Pin 222 Camshaft Drive Gear 223 Camshaft Timing Gear 225 Timing Chain 226 Camshaft Timing Gear Bolt 227 ming Chain Tensioner Bracket 28 Timing Chain Tensioner Bracket Bolt 29 Timing Chain Tensioner Shoe 300 Water Pump 301 Water Pump Bypass Hose Clamp 302 Water Pump Bypass Hose2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Water Pump Gasket 304) Water Pump Bolt 305 Water Pump Pulley 306 Water Pump Pulley Bolt 413 Oil Filter 418 Oil Level Indicator Tube Bolt 419 Oil Level Indicator Tube 420 Oil Level Indicator 424 Oil Pressure Relief Valve O-Ring Seal 430 Oil Filter Bypass Valve 431 Oil Cooler Adapter Bolt 432 Oil Cooler Adapter 433 Oil Cooler Adapter Seal 434 Oil Cooler Adapter Gasket 706 Oil Pressure Sensor Fitting 707 Oil Pressure Sensor 708 Knock Sensor 709 Knock Sensor Bolt 745 Engine Lift Bracket - Front 746 Engine Lift Bracket Stud - Front 747 Engine Lift Bracket Bolt - Front2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 113 : Lower Engine View 2 Courtesy of GENERAL MOTORS CORP. Callouts For Fig. El Callout Component Name 101 Crankshaft Main Bearing - Thrust 101 Crankshaft Main Bearing - Thrust 102 Crankshaft Main Bearing 102 Crankshaft Main Bearing 103 Crankshaft Balancer Key 104 Crankshaft 106 Crankshaft Main Bearing Cap 107 Crankshaft Main Bearing Cap - Thrust 108 Crankshaft Main Bearing Cap Bolt 109 Crankshaft Rear Oil Seal Housing Gasket 110 Crankshaft Rear Oil Seal Housing Locating Pin2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 1 Crankshaft Rear Oil Seal Housing Stud 112 Crankshaft Rear Oil Seal Housing 13 Crankshaft Rear Oil Seal Housing Nut 4 Crankshaft Rear Oil Seal 115 Crankshaft Rear Oil Seal Housing Bolt 133, Crankshaft Position Sensor Reluctor Ring 134 Crankshaft Balancer 135 Crankshaft Balancer Weight 136 Crankshaft Drive Belt Pulley 137 Crankshaft Drive Belt Pulley Bolt 138 Crankshaft Balancer Washer 139 Crankshaft Balancer Bolt 140 Flywheel - Auto Transmission 41 Flywheel Bolt 142 Flywheel - Manual Transmission 143 Flywheel Weight - Manual Transmission 224 Crankshaft Timing Sprocket 400 Oil Pan 401 Oil Pan Drain Plug Seal 402 Oil Pan Drain Plug 403 Oil Pan Bolt 404 Oil Pan Baffel 405 Oil Pan Baffel Bolt 406 Oil Pan Gasket 407 Oil Pump Bolt 408 Oil Pump Pick Up Screen 409 Oil Pump 410 Oil Pump Drive Retainer 411 Oil Pump Drive Shaft 412 Oil Pump Locating Pin 435 Oil Pan Nut 436 Crankshaft Rear Oil Seal Housing Stud 521 Crankshaft Front Oil Seal 742 Crankshaft Position Sensor Seal 743 Crankshaft Position Sensor 744 Crankshaft Position Sensor Bolt ENGINE IDENTIFICATION2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Fig. 6: Locating Vehicle Identification Number Derivative Courtesy of GENERAL MOTORS CORP. + The Vehicle Identification Number (VIN) Derivative is located on the left side rear of the engine block (1) or on the right side rear (2) and typically is a9 digit number stamped or laser etched onto the engine at the vehicle assembly plant o The first digit identifies the division. © The second digit identifies the model year. o The third digit identifies the assembly plant. o The fourth through ninth digits are the last six digits of the VIN.2004 Chevrolet $10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Fig. 7: Locating Engine Identification Number (Romulus Engine Plant) Courtesy of GENERAL MOTORS CORP. « Engines built at the Romulus engine plant have the engine identification number located at the right front top of the engine block. © The first digit (1) is the source code. o The second and third digits (2) are the month of build. o The fourth digit (3) is the hour of the build. o The fifth and sixth digits (4) are the date of build. o The seventh, eighth, and ninth digits (5) are the broadcast code. DIAGNOSTIC INFORMATION AND PROCEDURES DIAGNOSTIC STARTING POINT - ENGINE MECHANICAL Begin the system diagnosis by reviewing the Disassembled Views, Engine Component nm New Product Information and the Drive Belt2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma System Description. Reviewing the description and operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the description and operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Engine Mechanical in order to identify the correct procedure for diagnosing the system and where the procedure is located. SYMPTOMS - ENGINE MECHANICAL Strategy Based Diagnostics 1. Perform the Diagnostic System Check - Engine Controls in Engine Controls - 4.3L before using the symptom tables, if applicable 2. Review the system operations in order to familiarize yourself with the system functions. Refer to Disassembled Views, Engine Component Description, Lubrication Description, New Product Information and to Drive Belt System Description. All diagnosis on a vehicle should follow a logical process. S uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system problem. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Strategy Based Diagnosis in General Information. Visual/Physical Inspe « Inspect for aftermarket devices which could affect the operation of the Engine. Refer to Checking Aftermarket Accessories in Wiring Systems « Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom # Check for the correct oil level, proper oil viscosity, and correct filter application. « Verify the exact operating conditions under which the concern exists. Note factors such as engine RPM, ambient temperature, engine temperature, amount of engine warm-up time, and other specifics. « Compare the engine sounds, if applicable, to a known good engine and make sure you are not trying to correct a normal condition. Intermittent Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly. Symptom List Refer to a symptom diagnostic procedure from the following list in order to diagnose the2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma symptom: Base Engine Misfire with Exces Engine Compression Test Engine Noise Under Load « Oil Consumption Diagnosis « Oil Pressure Diagnosis and Testing « Oil Leak Diagnosis BASE ENGINE MISFIRE WITHOUT Base Engine Misfire without Internal En; Engine Noise on Start-Up, but Only L: Upper Engine Noise, Regardless of Engine Speed Lower Engine Noise, Regardless of Engine Speed Base Engine Misfire with Abnormal Internal Lower Engine Ni Base Engine Misfire with Abnormal Valve Train Noise Base Engine Misfire with Coolant Consumption INTERNAL ENG ‘ine N Base Engine Misfire without Internal Engine Noises ¢ Oil Consumption ting a Few Seconds Engine Will Not Crank - Crankshaft Will Not Rotate Cause Correction High oil pressure Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing. Repair or replace damaged components as required. Worn, damaged, or improperly installed accessory drive belt - severe cracking, bumps or missing segments A misfire DTC may be present without an actual misfire condition. Inspect the accessory drive system components. Repair or replace damaged components as required, Refer to Drive Belt Replacement. Worn, damaged, or improperly installed accessory drive system components A misfire DTC may be present without an actual misfire condition. Inspect the accessory drive system components. Repair or replace damaged components as required. Damaged, loose or improperly installed crankshaft balancer A misfire DTC may be present without an actual misfire condition. Inspect the crankshaft balancer. Repair or replace damaged components as required. Refer to Crankshaft Balancer Replacement.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Worn, damaged, or improperly installed crankshaft reluctor wheel ‘A worn or damaged crankshaft reluctor wheel can result in different symptoms depending on the severity and location of the wear or damage. Systems with electronic communications, DIS or coil per cylinder, and severe reluctor ring damage may exhibit periodic loss of crankshaft position, stop delivering a signal, and then re-syne the crankshaft position. Systems with electronic communication, DIS or coil per cylinder, and slight reluctor ring damage may exhibit no loss of crankshaft position and no misfire may occur. However, a DTC P0300 may be set. « Systems with mechanical communications, high voltage switch, and severe reluctor ring damage may cause additional pulses and effect fuel and spark delivery. A DTC P0300 or P0336 may be set. Inspect the crankshaft position sensor. Inspect the crankshaft reluctor wheel Inspect the crankshaft Repair or replace damaged components as required. Damaged, loose or improperly installed engine flywheel A misfire DTC may be present without an actual misfire condition: Inspect the flywheel Repair or replace damaged components as required. Refer to Engine Flywheel Replacement. Damaged, improperly installed or restricted exhaust em, collapsed or dented pipes, plugged mufflers or malfunctioning catalytic converters A DTC may be present without an actual fault condition. Inspect the exhaust system components. Repair or replace damaged components as required Worn, damaged or improperly installed vacuum hoses Inspect the vacuum system components. Repair or replace damaged components as required. Damaged or improperly installed MAP Inspect the MAP sensor.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma sensor, sealing grommet nicked, torn or missing Repair or replace damaged components as required. Damaged or improperly installed throttle body Inspect the throttle body. Repair or replace damaged components as required. Damaged or improperly installed intake manifold Inspect the intake manifold. Repair or replace damaged components as required. Damaged or improperly installed cylinder head Oil consumption may or may not cause the engine to misfire. Inspect the spark plugs. Refer to Spark Plug Inspection in Engine Controls. Verify engine compression. Refer to Engine Compression Test. Inspect the cylinder heads. Inspect the engine block Repair or replace damaged components as required. Worn, damaged or loose valve rocker arm Inspect the valve rocker arms. Repair or replace damaged components as required. Worn, damaged or loose valve rotator Inspect the valve rotators Repair or replace damaged components as required. Worn, damaged, loose or broken valve spring Inspect the valve springs. Repair or replace damaged components as required. Worn, damaged or stuck valve, carbon on the valve stem or valve seat Inspect the valves. Inspect the valve guides. Repair or replace damaged components as required. Wor or damaged valve guide Inspect the valve guides. Inspect the valves. Repair or replace damaged components as required. Wor, damaged, loose or bent valve push rod Inspect the valve push rods. Repair or replace damaged components as required.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Worn, damaged or dirty valve lifter Inspect the valve lifters. Inspect the camshaft. Repair or replace damaged components as required. Worn or damaged camshaft lobe Inspect the camshaft Inspect the valve lifters. Repair or replace damaged components as required. Worn, damaged or loose timing chain and sprockets Inspect the timing chain and sprockets. Repair or replace damaged components as required. Worn, damaged or improperly installed piston Pistons must be installed with the mark, or dimple, on the top of the piston, facing the front of the engine: piston pins must be centered in the connecting rod pin bore. Oil consumption may or may not cause the engine to misfire. Inspect the spark plugs. Refer to Spark Plug Inspection in Engine Controls Verify engine compression, Refer to Engine Compression Test Inspect the cylinder bores. Inspect the pistons Inspect the piston pins. Inspect the connecting rods. Repair or replace damaged components as required. BASE ENG! MISFIRE WIT ABNORMAL INTERNAL LOWER ENGINE NOISES Base Engine Misfire with Abnormal Internal Lower Engine Noises Cause Correction Worn, damaged, or improperly installed accessory drive belt - severe cracking, bumps or mi ig segments A misfire DTC may be present without an actual misfire condition. Inspect the accessory drive sys components. Repair or replace damaged components as required. Refer to Drive Belt Replacement Worn, damaged, or improperly installed accessory drive system components A misfire DTC may be present without an actual misfire condition. Inspect the accessory drive system components. Repair or replace damaged components as required. Wor, damaged, improperly installed or Inspect the crankshaft balancer2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma loose crankshaft balancer ‘A misfire code may be present without an actual misfire condition. Repair or replace damaged components as required. Refer to Crankshaft Balancer Replacement. Worn, damaged, improperly installed or loose engine flywheel A misfire code may be present without an actual misfire condition. Inspect the engine flywheel Repair or replace damaged components as required. Refer to Engine Flywheel Replacement Worn, damaged or improperly installed piston Pistons must be installed with the mark, or] dimple, on the top of the piston, facing the front of the engine: piston pins must be centered in the connecting rod pin bore. Oil consumption may or may not cause the engine to misfire. Inspect the spark plugs. Refer to Spark Plug Inspection in Engine Controls. Verify engine compression. Refer to Engine Compression Test Inspect the cylinder bores. Inspect the pistons. Inspect the piston pins. Inspect the connecting rods. Repair or replace damaged components as required. Worn, damaged or improperly installed crankshaft thrust bearing A misfire code may be present without an actual misfire condition. Inspect the crankshaft. Inspect the crankshaft thrust bearing. Repair or replace damaged components as required, BASE ENG! MISFIRE WIT! BNORMAL VALVE TRAIN NOISE Base Engine Misfire with Abnormal Valve Train Noise Cause Correction Worn, damaged or loose rocker arm Inspect the valve rocker arms. Repair or replace damaged components as required. Wom, damaged, loose or bent valve push rod Inspect the valve push rods. Repair or replace damaged components as required. Worn, damaged or stuck valve, carbon on the valve stem or valve seat Inspect the valves. Insp: ct the valve guides. Repair or replace damaged components as required. Worn, damaged or dirty valve lifter Inspect the valve lifters.2004 ENGINE Engine Mechani 2004 Chevrolet S10 Pickup ical - 4.3L - BlazeriS-10, Jimmy/Sonoma Inspect the camshaft. Repair or replace damaged components as required. Wor or damaged camshaft lobe Inspect the camshaft. Inspect the valve lifters. Repair or replace damaged components as required. Worn, damaged or loose timing chain and sprockets Inspect the timing chain and sprockets. Repair or replace damaged components as required, Base Engine Misfire with Coolant Consui BASE ENGINE MISFIRE WITH COOLANT CONSUMPTION mption Cause Correction Damaged or improperly installed cylinder head Coolant consumption may or may not cause the engine to misfire. # Inspect the spark plugs. Refer to Spark Plug Inspection in Engine Controls Verify engine compression. Refer to Engine Compression Test Inspect the cylinder heads. Inspect the engine block. Repair or replace damaged components as required. BASE ENG E MISFIRE WITH EXCI SIVE Base Engine Misfire with Excessive Oil C OIL CONSUMPTION ‘onsumption Cause Correction Worn or damaged valve Inspect the valves. Inspect the valve guides. Repair or replace damaged components as required. Worn, damaged or improperly i piston rings Piston rings must be installed with the mark, or dimple, on the top of the piston ring, facing up. stalled Inspect the spark plugs. Refer to Spark Plug Inspection in Engine Controls « Verify engine compression. Refer to Engine Compression Test2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Inspect the cylinder bores. Inspect the pistons. Inspect the piston pins. Inspect the connecting rods. Repair or replace damaged components as required ENGINE NOISE ON START-UP, BUT ONLY LASTING A FEW SECONDS Engine Noise on Start-Up, but Only Lasting a Few Seconds Cause Correction Incorrect engine oil, viscosity Install the correct engine oil and oil filter. Refer to Engine Oil and Oil Filter Replacement. Incorrect oil filter, without anti-drainback feature Install the correct engine oil and oil filter. Refer to Engine Oil and Oil Filter Replacement. filter by-pass valve Wom, damaged or improperly installed oil « Inspect the oil filter by-pass valve. # Repair or replace damaged components as required. High valve lifter leak down rate # Inspect the valve lifters, Repair or replace damaged components as required. Worn, damaged or improperly installed crankshaft thrust bearing Inspect the crankshaft. Inspect the crankshaft thrust bearing. Repair or replace damaged components as required. UPPER ENGINE NOISE, REGARDLESS OF ENGINE SPEED Upper Engine Noise, Regardless of Engine Speed Cause Correction Low oil pr sure, « Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing. # Repair or replace damaged components as required. Improper lubrication of the valve train components # Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing ‘ Inspect the valve rocker arms.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Inspect the valve push rods. Inspect the valve lifters. Inspect the oil filter bypass valve. Inspect the oil pump and pump screen. Inspect the engine block oil galleries. Repair or replace damaged components as required. Wom, damaged or improperly installed valve rocker arm Inspect the valve rocker arms. Repair or replace damaged components as required. Wom or damaged valve rotator Inspect the valve rotators. Repair or replace damaged components as required. Broken valve spring Inspect the valve springs. Repair or replace damaged components as required. Worn, damaged or stuck valves, carbon on the valve stem or valve seat Inspect the valves. Inspect the valve guides, Repair or replace damaged components as required. Worn or damaged valve guide Inspect the valve guides. Inspect the valves. Repair or replace damaged components as required. Worn, damaged or bent valve push rod Inspect the valve rocker arms. Inspect the valve push rods Inspect the valve lifters. Repair or replace damaged components as required. Worn, damaged or dirty valve lifter Inspect the valve lifters. Repair or replace damaged components as required. Worn or damaged camshaft lobes Inspect the engine camshaft lobes Repair or replace damaged components as required.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Worn, damaged, improperly installed or Inspect the timing chain and loose timing chain and sprockets sprockets. Repair or replace damaged components as required. Worn, damaged or improperly installed timing chain tensioner, if equipped ‘in tensioner. . Inspect the timing cl Repair or replace damaged components as required. LOWER ENGINE NOISE, REGARDLESS OF ENGINE SPEED Lower Engine Noise, Regardless of Engine Speed Cause Correction Low oil pressure ¢ Verify oil pressure. Refer to Oil Pressure Diagnosis and Testing. « Repair or replace damaged components as required. Detonation or spark knock « Verify the operation of the ignition controls system. Refer to Diagnostic System Check - Engine Controls in Engine Controls. # Repair or replace damaged components as required. Worn, damaged or improperly installed « Inspect the accessory drive system accessory drive belt - severe cracking, es bumps or missing segments in the SE STARTER # Repair or replace damaged components as required. Worn, damaged or improperly installed « Inspect the accessory drive system accessory drive system components components. « Repair or replace damaged components as required. Worn, damaged or improperly installed « Inspect the crankshaft balancer crankshaft balancer # Inspect the crankshaft + Repair or replace damaged components as required. Wom, damaged or improperly installed engine flywheel Inspect the engine flywheel Inspect the engine flywheel bolts. Inspect the torque converter. Inspect the torque converter bolts.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Inspect the crankshaft. Repair or replace damaged components as required. Worn, damaged or improperly installed torque converter « Inspect the torque converter. # Inspect the torque converter bolts. # Inspect the engine flywheel. « Repair or replace damaged components as required. Damaged oil pan, contacting the oil pump screen An oil pan that has been damaged may loosen, improperly position or restrict oil flow at the oil pump screen, preventing proper oil flow to the oil pump. Inspect the oil pan. « Inspect the oil pump # Repair or replace damaged components as required een. Worn, damaged, improperly installed or restricted oil pump screen An oil pan that has been damaged may loosen, improperly position or restrict oil flow at the oil pump screen, preventing proper oil flow to the oil pump. Inspect the oil pan. « Inspect the oil pump screen. + Repair or replace damaged components as required. Worn, damaged or improperly installed piston Pistons must be installed with the mark, or} dimple, on the top of the piston, facing the front of the engine: piston pins must be centered in the connecting rod pin bore. # Inspect the spark plugs. Refer to Spark Plug Inspection in Engine Controls + Verify engine compression. Refer to Engine Compression Test. « Inspect the cylinder bores. « Inspect the pistons. « Inspect the piston pins. « Inspect the connecting rods. # Repair or replace damaged components as required. Wor, damaged or improperly installed connecting rod bearing « Inspect the connecting rods. Inspect the connecting rod bearings. « Inspect the crankshaft connecting rod journals « Repair or replace damaged components as required. Worn, damaged or improperly insta crankshaft bearing # Inspect the crankshaft bearings.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma ENGINE NOISE UNDER LOAD Engine Noise Under Load Inspect the crankshaft journals. # Repair or rep mponents as required, Cause Correction Low oil pressure # Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing, # Repair or replace as required Detonation or spark knock « Verify the correct operation of the ignition controls. Refer to Diagnostic System Check - Engine Controls in Engine Controls « Repair or replace damaged components as required. Worn, damaged or improperly installed engine flywheel « Inspect the engine flywheel « Inspect the engine flywheel bolts. Inspect the torque converter. Inspect the torque converter bolts. « Inspect the crankshaft. + Repair or replace damaged components as required. Worn, damaged or improperly installed torque converter « Inspect the torque converter. « Inspect the torque converter bolts. « Inspect the engine flywheel. # Repair or replace damaged components as required. Worn, damaged or improperly installed pistons Pistons must be installed with the mark, or dimple, on the top of the piston, facing the front of the engine; piston pins must be centered in the connecting rod pin bore. « Inspect the cylinder bores. « Inspect the pistons. « Inspect the piston pins. « Inspect the connecting rods. # Repair or replace damaged components as required. Worn, damaged or improperly installed connecting rod bearing Inspect the connecting rods. « Inspect the connecting rod bearings.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma # Inspect the crankshaft connecting rod journals, # Repair or replace damaged components as required. Worn, damaged or improperly installed crankshaft bearing Inspect the crankshaft bearings. « Inspect the crankshaft journals. # Repair or replace damaged components as required. ENGINE WILL NOT CRANK - CRANKSHAFT WILL NOT ROTATE Engine Will Not Crank - Crankshaft Will Not Rotate Cause Correction Seized accessory drive system component 1, Remove accessory drive belts 2. Rotate crankshaft by hand at the balancer or flywheel location. Hydraulically locked eylinder # Coolant/antifreeze in cylinder # Oil in cylinder « Fuel in cylinder 1. Remove spark plugs and check for fluid 2. Inspect for broken head gasket 3. Inspect for cracked engine block or cylinder head 4. Inspect for a sticking fuel injector. Seized automatic transmission torque converter 1. Remove the torque converter bolts 2. Rotate crankshaft by hand at the balancer or flywheel location. Seized manual transmission 1. Disengage the clutch. 2. Rotate crankshaft by hand at the balancer or flywheel location Refer to Unit Repair Manual - Manual Transmi mn. Broken timing chain and/or gears Inspect timing chain and gears. Repair a required. Seized balance shaft Inspect balance shaft Repair as required Material in cylinder Broken valve Inspect cylinder for damaged components and/or foreign materials. Repair or replace as required.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Piston material « Foreign material Seized crankshaft or connecting rod bearings # Inspect crankshaft and connecting rod bearings. « Repair as required Bent or broken connecting rod « Inspect connecting rods. « Repair as required. Broken crankshaft # Inspect crankshaft # Repair as required COOLANT IN COMBUSTION CHAMBER Coolant in Combustion Chamber. Cause Correction DEFINITION: Ex Rotate. coolant in the cylinder bore 3. Inspect by performing a cylinder leak-down test. During this test, excess sive white smoke and/or coolant type odor coming from the exhaust pipe may indicate coolant in the combustion chamber. Low coolant levels, an inoperative cooling fan, or a faulty thermostat may lead to an "overtemperature” condition which may cause engine component damage. 1A slower than normal cranking speed may indicate coolant entering the combustion chamber. Refer to Engine Will Not Crank - Crankshaft Will Not 2. Remove the spark plugs and inspect for spark plugs saturated by coolant or e air bubbles within the coolant may indicate a faulty gasket or damaged component . Inspect by performing a cylinder compression test. Two cylinders "side-by-side" on the engine block, with low compression, may indicate a failed cylinder head gasket. Refer to Engine Compression Test. Cracked intake manifold or failed gasket Replace the components as required Faulty cylinder head gasket Replace the head gasket and components as required, Refer to Cylinder Head Cleaning and Inspection and Cylinder Head Replacement - Left or Cylinder Head Replacement - Right Warped cylinder head Machine the cylinder head to the proper flatness, if applicable and replace the cylinder head gasket. Refer to Cylinder Head Cleaning and Inspection Cracked cylinder head Replace the cylinder head and gasket2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Cracked cylinder liner or engine block __|Replace the components as required. Cylinder head or engine block porosity _ [Replace the components as required. COOLANT IN ENGINE OIL Coolant in Engine Oil Cause Correction DEFINITION: Foamy or discolored oil or an engine oil "overfill" condition may indicate coolant entering the engine crankcase. Low coolant levels, an inoperative cooling fan, or a faulty thermostat may lead to an "overtemperature" condition which may cause engine component damage. Contaminated engine oil and oil filter should be changed. 1. Inspect the oil for excessive foaming or an overfill condition. Oil diluted by coolant may not properly lubricate the crankshaft bearings and may lead to component damage. Refer to Lower Engine Noise, Regardless of Engine Speed . Inspect by performing a cylinder leak-down test. During this test, excessive air bubbles within the cooling system may indicate a faulty gasket or damaged component. 3. Inspect by performing a cylinder compression test. Two cylinders "side-by-side" on the engine block with low compression may indicate a failed cylinder head gasket. Refer to Engine Compression Test. Nv Faulty external engine oil cooler Replace the components as required. Faulty eylinder head gasket Replace the head gasket and components as required, Refer to Cylinder Head Cleaning and Inspection and Cylinder Head Replacement - Left or Cylinder Head Replacement - Right Warped cylinder head Machine the cylinder head to proper flatness, if applicable, and replace the cylinder head gasket. Refer to Cylinder Head Cleaning and Inspection. Cracked cylinder head Replace the cylinder head and gasket. Cracked cylinder liner or engine block [Replace the components as required. Cylinder head, block, or manifold porosity [Replace the components as required. ENGINE COMPRESSION TEST 1, Ensure that the vehicle batteries are in good condition, and fully charged. 2. Operate the vehicle until the engine is at normal operating temperature. 3. Disconnect the positive ignition coil wire plug from the ignition coil.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Disconnect the fuel injector electrical connector. Remove all of the spark plugs NOTE: Do not insert objects into the throttle plate opening. Damage to the throttle body can result, requiring replacement of the throttle body assembly. Block the throttle linkage wide open. Install the engine cylinder compression gage to the cylinder being tested. Using the vehicle starter motor, rotate, or crank the engine for 4 compression strokes, or puffs, for the cylinder being tested. If the engine rotates for more than 4 compression strokes, test the cylinder again. Record the compression reading, Remove the engine cylinder compression gage from the cylinder being tested Repeat steps 8-11 for each additional cylinder. All cylinders must be tested to obtain valid test results. If any cylinders have low compression, inject approximately 15 ml (1 0z) of engine oil into the cylinder through the spark plug hole. Repeat steps 8-11 for all low compression cylinders The minimum compression in any one cylinder should not be less than 70 percent of the highest cylinder. No cylinder should read less than 690 kpa (100 psi). For example, if the highest pressure in any one cylinder is 1035 kPa (150 psi), the lowest allowable pressure for any other cylinder would be 725 kPa (105 psi). Multiply the highest cylinder pressure by 70 percent, 1035 kPa x 70 percent = 725 kPa (150 psi x 70 percent = 105 psi), in order to determine the lowest allowable pressure in any other cylinder. « Normal The compression builds up quickly and evenly to the specified compression « Piston rings leaking Compression is low on the first compression stroke. The compression builds up on the following strokes, but does not reach normal. Compression improves considerably when you add oil. Valves leaking Compression is low on the first compression stroke. The compression does not build up on the following strokes, and does not reach normal. Compression does not improve much, if at all, when you add oil. » Head gasket leaking2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Compression is low on the first stroke. The compression does not build up on the following strokes, and does not reach normal. Compression does not improve much, if at all, when you add oil. Adjacent cylinders have the same, or similar, low compression readings 15, If one or more cylinders fails to meet the minimum specified compression, repair or replace all damaged or worn components and test the engine again. CYLINDER LEAKAGE TEST Tools Required J 35667-A Cylinder Head Leakdown Tester. See Special Tools and Equipment. With the use of air pressure, a cylinder leakage test will aid in the diagnosis. Use the cylinder leakage test in conjunction with the engine compression test in order to isolate the cause of leaking cylinders. CAUTION: Refer to Battery Disconnect Caution in Cautions and Notices. 1, Disconnect the battery ground negative cable. 2. Remove the spark plugs. Refer to Spark Plug Replacement in Engine Controls - 4.3L. 3. Rotate the crankshaft to place the piston in the cylinder being tested at top dead center (TDC) of the compression stroke, with both valves closed. 4. Install the J 35667-A IMPORTANT: It may be necessary to hold the crankshaft balancer bolt to prevent piston movement. w Apply shop air pressure to the J 35667-A and adjust according to the manufacturer instructions. IMPORTANT: Perform the leakage test on all cylinders and record the values before doing any repairs. 6. Record the cylinder leakage value, Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions: A. Air leakage from the intake or exhaust system may indicate a wom or burnt valve ora broken valve spring. 1. Remove the valve rocker arm cover of the suspect cylinder head, Refer to Valve Rocker Arm Cover Replacement - Left or Valve Rocker Arm2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Cover Replacement - Right. .. Ensure that both valves are closed. Inspect the cylinder head for a broken valve spring, . Remove and inspect the suspect cylinder head. Refer to Cylinder Head Replacement - Left or Cylinder Head Replacement - Right. B. Air leakage from the crankcase, oil level indicator, or oil fill tube may indicate worn piston rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block or a damaged cylinder head RwN 1, Remove the piston from the suspect cylinder. Refer to Piston, Connecting Rod, and Bearing Removal or Piston, Connecting Rod, and Bearing Installation 2. Inspect the piston and connecting rod assembly. Refer to Piston, Connecting Rod, and Bearings Cleaning and Inspection. 3. Inspect the engine block. Refer to Engine Block Cleaning and Inspection 4, Inspect the cylinder head. Refer to Cylinder Head Cleaning and Inspection. 7. Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket. ‘A. Remove both cylinder heads, Refer to Cylinder Head Replacement - Left or Cylinder Head Replacement - Right B. Inspect both cylinder heads. Refer to Cylinder Head Cleaning and Inspection. C. Inspect the engine block. Refer to Engine Block Cleaning and Inspection 8. Remove the J 35667-A . 9. Install the spark plugs. Refer to Spark Plug Replacement in Engine Controls - 4.3L. CAUTION: Refer to Battery Disconnect Caution in Cautions and Notices. 10. Connect the battery ground negative cable. OIL CONSUMPTION DIAGNOSIS Excessive oil consumption, not due to leaks, is the use of | liter (1 quart) of engine oil within 3 200 kilometers (2,000 miles), However, during initial engine break-in periods 4 828-6 437 kilometers (3,000-4,000 miles), oil consumption may exceed | liter (1 quart) or more. The causes of excessive oil consumption include the following conditions: External oil leaks Tighten the bolts and/or replace gaskets and oil seals as necessary.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Incorrect oil level or improper reading of oil level indicator With the vehicle on a level surfaci correct oil level. , allow adequate drain down time and check for the Improper oil viscosity Use recommended SAE viscosity for the prevailing temperatures Continuous high speed driving and/or severe usage Crankcase ventilation system restrictions or malfunctioning components Valve guides and/or valve stem oil seals worn, damaged, or the seal omitted Ream the valve guides and install oversize service valves and/or new valve stem oil eals. Piston rings broken, improperly installed, worn, or not seated properly Allow adequate time for the piston rings to seat. Replace broken or worn piston rings as necessary fitted « Piston improperly installed or mii OIL PRESSURE DIAGNOSIS AND TESTING 1. With the vehicle on a level surface, allow adequate drain down time, 2-3 minutes, and measure for a low engine oil level. Add the recommended grade engine oil, and fill the crankcase until the oil level measures FULL on the oil level indicator. 2, Operate the engine and verify low or no oil pressure on the vehicle oil pressure gage or the oil indicator light Listen for a noisy valve train or a knocking noise. 3. Inspect for the following: Engine oil diluted by moisture or unburned fuel mixtures Improper engine oil viscosity for the expected temperature . Incorrect or faulty oil pressure gage sensor Incorrect or faulty oil pressure gage . Plugged oil filter « Malfunctioning oil filter bypass valve2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma Remove the oil pressure gage sensor or another engine block oil gallery plug. Install an oil pressure gage. we Start the engine and then allow the engine to reach normal operation temperature Measure the engine oil pressure at the following RPM ao ecification: A. 42 kPa (6 psig) minimum, at 1,000 RPM B. 125 kPa (18 psig) minimum, at 2,000 RPM C. 166 kPa (24 psig) minimum, at 4,000 RPM 8. If the engine oil pressure is below minimum specifications, inspect the engine for one or more of the following: + Oil pump worn or dirty * Malfunctioning oil pump pressure relief valve + Oil pump screen loose, plugged, or damaged « Excessive bearing clearance # Cracked, porous or restricted oil galleries « Engine block oil gallery plugs missing or incorrectly installed # Broken valve lifters OIL LEAK DIAGNOSIS Oil Leak Diagnosis Step ‘Action Yes No IMPORTANT: You can repair most fluid leaks by first visually locating the leak, repairi component, or by resealing the gasket surface. Once the leak is i of the leak. Repair the cause of the leak as welll as the leak itself. 9 or replacing the lentified, determine the cause 1. Operate the vehicle until it reaches normal operating temperature. 2. Park the vehicle on a level surface, over a large sheet of paper or other clean 1 surface. 3. Wait 15 minutes. 4. Check for drippings. Are drippings present? Goto Step2 | System OK [Can you identify the type of fluid and the approximate location of the leak? Go to Step 10 | Go to Step 3 1. Visually inspect the suspected area. Use2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma a small mirror to assist in looking at hard| to see areas. 2. Check for leaks at the following locations: * Sealing surfaces Fittings + Cracked or damaged components Can you identify the type of fluid and the approximate location of the leak? Go to Step 10 Go to Step 4 1. Completely clean the entire engine and surrounding components. 2. Operate the vehicle for several kilometers - miles at normal operating temperature and at varying speeds. 3. Park the vehicle on a level surface, over a large sheet of paper or other clean surface. 4. Wait 15 minutes. 5. Identify the type of fluid, and the approximate location of the leak. Can you identify the type of fluid and the approximate location of the leak? Go to Step 10 Go to Step 5 1. Visually inspect the suspected area. Use a small mirror to assist in looking at hard| to see areas. Nv . Check for leaks at the following locations: * Scaling surfaces + Fittings # Cracked or damaged components Can you identify the type of fluid and the approximate location of the leak? Go to Step 10 Go to Step 6 1. Completely clean the entire engine and surrounding components. N . Apply an aerosol-type powder, baby powder, foot powder, ete,, to the suspected area.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 3. Operate the vehicle for several kilometers (miles) at normal operating temperature and at varying speeds 4. Identify the type of fluid, and the approximate location of the leak, from the discolorations in the powder surface. Can you identify the type of fluid and the approximate location of the leak? Go to Step 10 Go to Step 7 1. Visually inspect the suspected area. Use a small mirror to assist in looking at hard] to see areas. 2. Check for leaks at the following. locations: * Sealing surfaces « Fittings + Cracked or damaged components Can you identify the type of fluid and the approximate location of the leak? Go to Step 10 Go to Step 8 Use J 28428-E High Intensity Black Light Kit in order to identify the type of fluid, and the approximate location of the leak. See Special Tools and Equipment. Refer to the manufacturer's instructions when using the tool. Can you identify the type of fluid and the approximate location of the leak? 1. Visually inspect the suspected area. Use a small mirror to assist in looking at hard to see areas. 2. Check for leaks at the following locations: * Sealing surfaces « Fittings * Cracked or damaged components Can you identify the type of fluid and the approximate location of the leak? Go to Step 10 Go to Step 10 Go to Step 9 System OK 1. Inspect the engine for mechanical2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma damage. Special attention should be shown to the following areas: # Higher than recommended fluid levels « Higher than recommended fluid pressures + Plugged or malfunctioning fluid filters or pressure bypass valves « Plugged or malfunctioning engine ventilation system + Improperly tightened or damaged fasteners, 10 Cracked or porous components Improper sealants or gaskets where required Improper sealant or gasket installation Damaged or worn gaskets or seals Damaged or wom sealing surfaces 2. Inspect the engine for customer modifications, Is there mechanical damage, or customer modifications to the engine? Goto Step 11 | System OK Repair or replace all damaged or modified 11 |components. Does the engine still leak oil? Goto Step 1 | System OK CRANKCASE VENTILATION SYSTEM INSPECTION/DIAGNOSIS, Results Of Incorrect Operation + A plugged valve or hose may cause the following conditions o Rough idle © Stalling or slow idle speed 0 Oil leaks © Oil in air cleaner o Sludge in engine # A leaking crank o Rough idle ¢ ventilation valve or hose may cause the following conditions2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma o Stalling o High idle speed Functional Cheek With these systems, any blow-by in excess of the system capacity, from a badly wom engine, sustained heavy load, etc., is exhausted into the air cleaner and is drawn into the engine. Proper operation of the crankcase ventilation system depends upon a sealed engine. If oil slugging or dilution is noted and the crankcase ventilation system is functioning properly, check the engine for a possible cause. Correct any problems. If an engine is idling rough, check for a clogged crankcase ventilation valve, a dirty vent filter, air cleaner element, or plugged hose. Replace as required. Use the following procedure: Remove the crankcase ventilation valve from the rocker arm cover. Operate the engine at idle. Place your thumb over the end of the valve in order to check for a vacuum. If there is no vacuum at the valve, check for the following items: + Plugged hoses * The manifold port ene The crankcase ventilation valve 4. Turn OFF the engine. Remove the crankcase ventilation valve. Shake the valve. Listen for the rattle of the check needle inside of the valve. If valve does not rattle, replace the valve, DRIVE BELT CHIRPING DIAGNOSIS Diagnostic Aids The symptom may be intermittent due to moisture on the drive belt(s) or the pulleys. It may be necessary to spray a small amount of water on the drive belt(s) in order to duplicate the customers concern. If spraying water on the drive belt(s) duplicates the symptom, cleaning the belt pulleys may be the probable solution. A loose or improper installation of a body component, a suspension component, or other items of the vehicle may cause the chirping noise. ‘Test Description The number(s) below refer to the step number(s) on the diagnostic table2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 2: The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table. 3: The noise may be an internal engine noise. Removing the drive belt and operating the engine for a brief period will verify the noise is related to the drive belt. When removing the drive belt(s) the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belt removed. 4: Inspect all drive belt pulleys for pilling. Pilling is the small balls or pills or it may be strings in the drive belt grooves from the accumulation of rubber dust. 6: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misalign pulley using a straight edge in the pulley grooves across two or three pulleys. If a misalign pulley is found refer to that accessory drive component for the proper installation procedure for that pulley. 10: Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed 12: Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley. 14: Replacing the drive belt when it is not damaged or there is not excessive pilling will only be a temporary repair. Drive Belt Chirping Diagnosis Step Action Yes No NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of chirping: * A high pitched noise that is heard once per revolution of the drive belt or a pulley. Chirping may occur on cold damp start up conditions and will subside once the vehicle reaches normal operating temperature. # Itusually occurs on cold damp mornings. Did you review the Drive Belt Symptom Go to 1 |operation and perform the necessary Symptoms - inspections? Engine Go to Step 2_| Mechanical 2 Verify that there is a chirping noise. Go to Diagnostic] Does the engine make the chirping noise? | Go to Step 3 Aids 1. Remove the drive belt.2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma 2. Operate the engine for no longer than Goto 3 30 to 40 seconds. Symptoms - Engine Does the chirping noise still exist? Mechanical | Go to Step 4 Inspect for severe pilling exceeding 1/3 of 4 |the belt groove depth. Does the belt grooves have pilling? Goto Step 5 | Go to Step 6 Clean the drive belt pulleys with a suitable 5 | wire brush Did you complete the repair? Goto Step 15 | Go to Step 6 6 Inspect for misalignment of the pulleys. Are any of the pulleys misaligned? Goto Step 7 | Go to Step 8 7 [Replace or repair any misaligned pulleys, Did you complete the repair? Go to Step 15 | Go to Step 8 g__||nspect for bent or eracked brackets Did you find any bent or cracked brackets? | _Go to Step 9 | Go to Step 10 4g [Replace any bent or eracked brackets Did you complete the repair? Go to Step 15 | Go to Step 10 Inspect for improper, loose or missing 10 | fasteners. Did you find the condition? Go to Step 11 | Go to Step 12 NOTE: Refer to Fastener Notice in Cautions and Notices. 11 | Tighten any loose fasteners.Replace any improper or missing fasteners. Refer to Fastener Tightening Specifications. Did you complete the repair? Go to Step 15 | Go to Step 12 12, | |nspect for a bent pulley Did you find the condition? Go to Step 13 | Go to Step 14 13. [Replace the bent pulley. Did you complete the repair? Go to Step 15 | Go to Step 14 Replace the drive belt. Refer to Drive Belt 14 |Replacement. Go to Diagnostic] Did you complete the repair? Go to Step 15 Aids Operate the system in order to verify the 15. |repair. Did you correct the condition? System OK | Go to Step 3 DRIVE BELT SQUEAL DIAGNOSIS Diagnostic Aids2004 Chevrolet S10 Pickup 2004 ENGINE Engine Mechanical - 4.3L - Blazer/S-10, Jimmy/Sonoma A loose or improper installation of a body component, a suspension component, or other items of the vehicle may cause the squeal noise. If the noise is intermittent, verify the ory drive components by varying their loads making sure they are operated to their maximum capacity. An overcharged A/C system, power steering system with a pinched hose or wrong fluid, or a generator failing are suggested items to inspect. ‘Test Description The number(s) below refer to the step number(s) on the diagnostic table. 2: The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table 3: The noise may be an internal engine noise. Removing the drive belt and operating the engine for a brief period will verify the squeal noise is the drive belt(s) or an accessory drive component. When removing the drive belt the water pump may not be operating and the engine may overheat, Also DTCs may set when the engine is operating with the drive belt removed. 4: This test is to verify that an accessory drive component does not have a seized bearing. With the belt remove test the bearings in the accessory drive components for turning smoothly. Also test the accessory drive components with the engine operating by varying the load on the components to verify that the components operate properly. his test is to verify that the drive belt tensioner operates properly. If the drive belt tensioner is not operating properly, proper belt tension may not be achieved to keep the drive belt from slipping which could cause a squeal noise 6: This test is to verify that the drive belt(s) is not too long, which would prevent the drive belt tensioner from working properly. Also if an incorrect length drive belt was installed, it may not be routed properly and may be turning an accessory drive component in the wrong direction. 7: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misalign pulley using a straight edge in the pulley grooves across two or three pulleys. Ifa misalign pulley is found refer to that accessory drive component for the proper installation procedure for that pulley. 8: This test is to verify that the pulleys are the correct diameter or width. Using a known good vehicle compare the pulley sizes. Drive Belt Squeal Diagnosis Step ‘Action Yes No NOTE: Refer to Belt Dressing Notice in Cautions and