SECTION 1B

SOHC ENGINE MECHANICAL

CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in B unless otherwise
noted.

TABLE OF CONTENTS
Description and Operation . . . . . . . . . . . . . . . . . . 1B-2 Air Filter Assembly . . . . . . . . . . . . . . . . . . . . . . . 1B-14
Engine Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-2 Air Filter Element . . . . . . . . . . . . . . . . . . . . . . . . . 1B-15
Engine Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . 1B-2 Positive Crankcase Ventilation (PCV) Hose
Cylinder Head and Valve Train . . . . . . . . . . . . . . 1B-2 and Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-15
Engine Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-3 Intake Manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-16
Crankshaft . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-3 Exhaust Manifold (Typical) . . . . . . . . . . . . . . . . . 1B-18
Connecting Rod . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-3 Exhaust Manifold (Euro III) . . . . . . . . . . . . . . . . 1B-20
Piston, Piston Ring and Piston Pin . . . . . . . . . . . 1B-3 Timing Belt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-21
Timing Belt and Pulley . . . . . . . . . . . . . . . . . . . . . 1B-4 Oil Pan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-23
Engine Mount . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-4 Oil Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-24
Component Locator . . . . . . . . . . . . . . . . . . . . . . . . 1B-5 Distributor Case . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-26
Cylinder Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-5 Cylinder Head and Gasket . . . . . . . . . . . . . . . . . 1B-28
Engine Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-6 Engine Mount Damping Block . . . . . . . . . . . . . . 1B-32
Manifold & Air Flow System . . . . . . . . . . . . . . . . . 1B-7 Engine Mount Front Damping Bush . . . . . . . . . 1B-34
Timing Belt & Engine Mount . . . . . . . . . . . . . . . . 1B-8 Engine Assembly . . . . . . . . . . . . . . . . . . . . . . . . . 1B-35
Diagnostic Information and Procedure . . . . . . . 1B-9 Unit Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-47
Compression Pressure Check . . . . . . . . . . . . . . . 1B-9 Cylinder Head and Valve Train
Components . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-47
Oil Pressure Check . . . . . . . . . . . . . . . . . . . . . . . . 1B-9
Engine Block Components . . . . . . . . . . . . . . . . . 1B-59
Adjustment of Valve Clearance . . . . . . . . . . . . . 1B-10
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-71
Ignition Timing Check and Adjustment
(Typical) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-11 Engine Specifications . . . . . . . . . . . . . . . . . . . . . 1B-71
Valve Timing Check and Adjustment . . . . . . . . 1B-12 Fastener Tightening Specifications . . . . . . . . . . 1B-73
Repair Instructions . . . . . . . . . . . . . . . . . . . . . . . . 1B-14 Special Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1B-75
On-Vehicle Service . . . . . . . . . . . . . . . . . . . . . . . . . 1B-14 Special Tools Table . . . . . . . . . . . . . . . . . . . . . . . 1B-75

DAEWOO M-150 BL2

1B – 2 SOHC ENGINE MECANICAL

DESCRIPTION AND OPERATION

ENGINE TYPE
The engine is 4-cycle, water-cooled, in-line 3 cylinders
with displacement of 796cc (68.5×72.0mm) (2.70×
2.83 in.).

Engine model F8C Type SOHC /

(Specifications) 2 Valve (MPI)
Maximum power (kw/rpm) 37.5 / 6,000
Maximum torque (NSm/rpm) 68.6 / 4,600
Compression ratio 9.3 : 1

D102B002

CYLINDER HEAD AND VALVE TRAIN

The cylinder head is made of cast aluminum alloy for
better strength in hardness with lightweight, and cam-
shaft (k) and rocker arm shaft (h) arranged in-line sup-
port.

D102B001

ENGINE LUBRICATION
The engine lubrication is of the wetsump method to draw
up the oil forced by the oil pump. The oil pump is of a
trochoid type, and mounted on crankshaft at crankshaft
pulley side (a). Oil is drawn up through oil pump pickup
tube (b) and passed through pump (c) to oil filter (d). The
filtered oil flows into two paths in engine block. In one
path (e), oil reaches crankshaft journal bearings. Oil
from crankshaft journal bearings is supplied to connect-
ing rod bearings by means of intersecting passages
drilled in crankshaft, and then injected from a small hole D102B003
provided on big end of connecting rod to lubricate piston
(f), rings, and cylinder wall. In another path (g), oil goes
up to cylinder head and lubricates rocker arm (i), valve The combustion chambers are formed into the manifold
(j), camshaft (k), etc. through the oil hole provided on the combustion chambers with increased squish parts for
rocker arm shaft (h). better combustion efficiency and its intake and exhaust

DAEWOO M-150 BL2

 SOHC ENGINE MECANICAL 1B – 3
parts are installed in the cross flow arrangement. The crankshaft (m) and its small end to piston pin to transmit
rocker arm (i) operates in seesaw motion to close and the power.
open the intake and exhaust valves (j) with camshaft by The big end is detachable, and its upper and lower parts
turning the rocker arm shaft of each intake and exhaust are fastened by bolting after the metal bearings (q) are
part. inserted.

ENGINE BLOCK
As the largest part of the engine components. the block PISTON, PISTON RING AND PISTON
(l) has all the necessary parts attached to outer surface
of it.
PIN
On the inside surface of block, there are bore surfaces Piston
by horning, which are cylinders, and on the periphery of The piston (r) is of the open skirt type and its crown is
the cylinders, there are the passages to prevent the exposed in the combustion chamber to generate power.
over-heated and to lubricate the engine block. Its land and skirt parts are made of coat aluminum alloy
which is light and has excellent heat conductivity in order
to meet its continuous and high speed reciprocation
CRANKSHAFT movement.
The crankshaft (m) is to convert the rectilinear motion
into the rotation motion through the connecting rod (n) Piston Ring
which transmits the power generated by combustion. It is composed of two compression rings (s) and one oil
On the one side of it, oil pump, crankshaft pulley and ring (t) and installed between the grooves of the piston
timing belt pulley are attached, and oil seal housing and to make the high speed reciprocating movement main-
flywheel are on the other side. taining a remarkable air tightness as well as cylinders. It
A special steel of high grade cast iron is used for the ma- is a critical parts to affect the compression pressure, oil
terial to stand the bending load and distortion. The mate- consumption, compression, blow by pressure and en-
rial of the main bearing (o) is aluminum alloy. The split gine performance.
thrust bearings (p) are inserted in the journal bearing
part (No.3). Piston Pin
The pin (u) is not fixed to the piston or connecting rod
and its both ends are assembled by the circlip (v) in the
full floating type. The pin is used to transmit the power
from the crown part of piston to connecting rod.

D102B004

CONNECTING ROD
D102B005
The connecting rods (n) are made of forged steel, and
its section is typed “I” with its big end connected to

DAEWOO M-150 BL2

1B – 4 SOHC ENGINE MECANICAL

TIMING BELT AND PULLEY ENGINE MOUNT

The timing belt connects the camshaft timing pulley (w) This is to absorb or reduce the engine vibration and im-
and the crankshaft timing pulley (x). The timing belt pact from the wheeled road. Engine mount is attached to
coordinates the crankshaft and the camshaft and keeps the engine–front side, the engine-right side and the en-
them synchronized. The timing belt also turns the cool- gine-rear side and one transaxle mount is attached to
ant pump (y). The timing belt and the pulleys are toothed the transaxle side.
so that there is no slippage between them. There is a
tension pulley (z) that maintains the correct timing belt
tension. The timing belt is made of a tough reinforced
rubber similar to that used on the serpentine drive belt.
The timing belt requires no lubrication.

D102B007

D102B006

D102B008

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 SOHC ENGINE MECANICAL 1B – 5

COMPONENT LOCATOR
CYLINDER HEAD

D12B4011

1 Oil Filler Cap 7 Cylinder Head Gasket

2 Cylinder Head Cover 8 Cylinder Head
3 Cylinder Head Cover (Euro III) 9 Intake Rocker Arm
4 Distributor Case 10 Exhaust Valve
5 Camshaft 11 Intake Valve
6 Exhaust Rocker Arm

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1B – 6 SOHC ENGINE MECANICAL

ENGINE BLOCK

D21B0011

1 Oil Level Gauge Stick 6 Flywheel

2 Piston 7 Crankshaft
3 Connecting Rod 8 Oil Pan
4 Engine Block 9 Oil Pump Strainer
5 Oil Filter 10 Oil Pump Assembly

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 SOHC ENGINE MECANICAL 1B – 7

MANIFOLD & AIR FLOW SYSTEM

D21B0021

1 Intake Manifold 7 Snorkel

2 Exhaust Gas Recirculation (EGR) Pipe 8 Oxygen Sensor
3 Exhaust Gas Recirculation (EGR) Valve and 9 Exhaust Manifold
Solenoid 10 Exhaust Manifold Heat Shield
4 Throttle Body Assembly 11 Exhaust Manifold Heat Shield (Euro III)
5 Air Filter Assembly 12 Exhaust Manifold (Euro III)
6 Resonator

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1B – 8 SOHC ENGINE MECANICAL

TIMING BELT & ENGINE MOUNT

D12B4041

1 Engine Mount Damping Block 9 Timing Belt Tensioner

2 Engine Mount Intermediate Bracket 10 Crankshaft Gear
3 Engine Mount Brace Bracket 11 Timing Belt Upper Front Cover
4 Transaxle Mount Bracket 12 Timing Belt Lower Front Cover
5 Transaxle Mount Damping Block 13 Crankshaft Pulley
6 Engine Mount Front Bracket 14 Engine Mount Lower Bracket
7 Engine Mount Front Damping Bush 15 Engine Mount Upper Bracket
8 Timing Belt

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 SOHC ENGINE MECANICAL 1B – 9

DIAGNOSTIC INFORMATION AND PROCEDURE

COMPRESSION PRESSURE CHECK OIL PRESSURE CHECK
Tools Required Tools Required
09915–64510 Compression Pressure Gauge 09915–77310 Oil Pressure Gauge
Check the compression pressure in the following proce- Prior to check oil pressure, check the followings:
dures: D Check oil level and add if required.
1. Warm up the engine to the normal operating tempera- D Replace the discolored, deteriorated or diluted oil.
ture (Cooling temperature : 80–90_C (176–194_F)).
D Check any oil leakage and repair the defective parts.
2. Stop the engine and then remove the high tension
Check the compression pressure in the following proce-
cable and the spark plug.
dures:
3. Disconnect the distributor optical sensor connector.
1. Remove the oil pressure switch (b) from the cylinder
4. Install the compression pressure gauge 09915–64510 block.
(a) in the hole of spark plug.
2. Install the oil pressure gauge 09915–77310 (c) to the
mounting place of the oil pressure switch.

D12B301A

D12B302A
5. Disengage the clutch in Neutral (to lighten starting
load on engine upon cranking), and depress the ac-
3. Start the engine and warm up to the normal operating
celerator all the way to make the throttle fully open.
temperature.
6. Crank the engine with the starting motor, and read the
4. Raise the engine speed up to 2,000rpm and then
highest pressure on the compression pressure gauge.
read oil pressure.
D The difference of measured value between cylinders
is 98.06kPa (14.22 psi) and less.
D On checking, make the connection perfectly airtight
ÁÁÁÁÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁ
Item Unit Standard
between the hole of spark plug and compression pres- kPa 245.15–294.18
Oil Pressure – 2000rpm
sure gauge. (psi) (35.55–42.66)

ÁÁÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁÁ
ÁÁÁÁÁ
ÁÁÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁÁ
ÁÁÁÁÁ
5. After checking, wrap the threads of oil pressure
Unit Standard Limit switch with a seal tape and tighten it to the specified

ÁÁÁÁÁÁ
Compression 1,176.72– torque 12–16 NSm (106–144 lb-in).

ÁÁÁÁÁÁ
Pressure 1,225.75 1,274.78 6. Start the engine and check oil pressure switch for oil
kPa(psi)

ÁÁÁÁÁÁ
– 400 rpm (177.73) (170.62– leakage.
184.84)

7. After checking, remove the gauge and install the re-

moved parts.

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 1B – 10 SOHC ENGINE MECANICAL

ADJUSTMENT OF VALVE
CLEARANCE
Adjust the valve clearance in the following procedures:
1. Remove the air filter/resonator assembly and the
relevant parts installed on the cylinder head cover.
2. Remove the cylinder head cover hexagon bolts and
remove the cover.
3. Turn over the crankshaft to make No.1 cylinder
matched with the compression top dead center.
(When the camshaft sprocket notch (d) is aligned with
the timing belt rear cover triangle pointer (e) and the
crankshaft sprocket point (f) is aligned with the oil D102B304
pump housing point (g), the compression top dead
center is on the ignition sequence for No. 1 cylinder.)
6. Check the valve clearance for the No. 1 cylinder ex-

ÁÁÁÁÁÁÁ
ÁÁÁÁ
ÁÁÁÁÁÁÁ
ÁÁÁ
haust top dead center.

ÁÁÁÁÁÁÁ
ÁÁÁÁ
ÁÁÁ
ÁÁÁÁÁÁÁ
ÁÁÁ
ÁÁÁÁÁÁÁ
ÁÁÁÁ ÁÁÁÁ
ÁÁÁ
Cylinder
Condition 1 2 3
No.

ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁ
Exhaust top dead
center of No.1
Intake f

ÁÁÁÁÁÁÁ
cylinder Exhaust f

Q f marks indicates the place where the valve clear-

ance can be checked and adjusted.
D Check and adjust the valve clearance (i) using thick-
ness gauge (j).
D102B303

4. Check the valve clearance for No. 1 cylinder com-

ÁÁÁÁÁÁÁ
ÁÁÁÁÁ
ÁÁÁ
ÁÁÁ
ÁÁÁ
pression top dead center.

ÁÁÁÁÁÁÁ
ÁÁÁÁÁ
ÁÁÁÁÁÁÁ ÁÁÁ
ÁÁÁÁÁ ÁÁÁ
ÁÁÁ ÁÁÁ
ÁÁÁ
Condition
ÁÁÁ
Cylinder
No.
1 2 3

ÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁ
Compression top Intake f f
dead center of

ÁÁÁÁÁÁÁ
No.1 cylinder Exhaust f

Q f marks indicates the place where the valve clear-

f

ance can be checked and adjusted. D102B305

5. If the checking for the valve clearance of No.1 cylin-
der compression top dead center is over, position
No.1 cylinder on the exhaust top dead center as rotat-
ing the crankshaft in a 360–degree arc. (When the
camshaft sprocket point (h) is aligned with the timing
belt rear cover triangle pointer (e), the exhaust top
dead center is on the ignition sequence for No. 1 cyl-
inder.)

D102B306

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 SOHC ENGINE MECANICAL 1B – 11
The measured value of valve clearance should meet the IGNITION TIMING CHECK AND
specified value. If not, adjust the valve clearance.
ADJUSTMENT (TYPICAL)
Important: In case of hot engine, warm up the engine
Note: Ignition timing could not be adjusted for Direct
until the electric cooling fan begins to work and stop the
Ignition System (Euro Stage III).
engine to adjust the clearance with 20–30 minutes there
from. Check and adjust the ignition timing in the following pro-
cedures:

ÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁ
Unit : mm (in.)
1. Warm up the engine to the normal operating tempera-

ÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁ
Item Specified value
ture.

ÁÁÁÁÁ
ÁÁÁÁÁ
Intake
0.15±0.02
(0.0059±0.0008)
2. Turn off the lamp and audio system and shift the shift
gear lever in Neutral.

ÁÁÁÁÁ
Cold
0.32±0.02

ÁÁÁÁÁ
Exhaust
Valve (0.0126±0.0008)

ÁÁÁÁÁ
Clearance

ÁÁÁÁÁ
Intake
0.25±0.02
(0.0098±0.0008)

ÁÁÁÁÁ
Hot
0.42±0.02

ÁÁÁÁÁ
Exhaust
(0.0165±0.0008)

8. When adjusting the valve clearance, loosen the ad-

just nut (k) and then tighten or loosen the adjust rod (l)
properly.

D12B3081

3. Connect terminal A and terminal C of ALDL connec-

tor using the wire (m) or connect the scan tool (n) with
ALDL connector.
4. Connect the timing light (o) with No. 1 cylinder high
tension cable and check the specified value for the
ignition timing, flashing notch on the crankshaft
pulley.

ÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁ Item Specified Value

ÁÁÁÁÁÁÁÁÁ
D102B307

Ignition timing – 950rpm 10_ BTDC

Important: In flashing the timing light, if crankshaft

pulley notch (p) is matched with the mark (10) for timing
check, the ignition timing is 10_ BTDC.

D102B309

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1B – 12 SOHC ENGINE MECANICAL
2. Turning the crankshaft clockwise twice, align the
notch (d) on the crankshaft pulley (c) with the mark 0
(e) for the timing check on the timing belt front lower
cover.

D102B310

5. If the ignition timing exceeds the specified value,

loosen the distributor bolts and adjust it to the speci-
fied ignition timing by turning the distributor body (s).
D102B313

3. Check if the notch (f) on the camshaft sprocket is

aligned with the triangle pointer (g) on the timing belt
rear cover.
Important: Notch (f) should be aligned with pointer (g)
to set the valve timing normally.

D102B311

VALVE TIMING CHECK AND

ADJUSTMENT
Check the valve timing in the following procedures:
1. After removing the high headlamp, loosen the bolts
D102B314
(a) and remove the timing belt front upper cover (b).

D102B312

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 SOHC ENGINE MECANICAL 1B – 13
Adjust the valve timing in the following procedures:
1. Loosen the bolt and remove the timing belt pulley (c). 4. Using the bolt, turn the crankshaft clockwise to align
In loosening the bolt, use the driver (h) in the picture the mark (m) on the crankshaft sprocket with the
shown. pointer (n) on the oil pump housing. Then, turn the
camshaft to align the notch (f) with the pointer (g).

D102B315
D102B318

2. Remove the oil level gauge guide tube (i) and the tim-
ing belt front lower cover (j). 5. Install the timing belt (l) and the tensioner (k). (Do not
tighten the tensioner bolt completely.)
Turning the crankshaft clockwise twice, align the
mark (m) with the pointer (n) and tighten the tensioner
bolt to 15–23 NSm (11–17 lb-ft).

D102B316

3. Remove the timing belt tensioner (k) and the timing

D12B319A
belt (l).

6. Install all removed parts.

D102B317

DAEWOO M-150 BL2