LUBRICATION
SYSTEM
Purpose
1. Lubrication for moving Parts.
2. Cooling
3. Sealing
4. Cleaning
5. Damping
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LUBRICATION PRINCIPLES
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Engine Oil
▣ Types of Oils
1. Mineral Oil
2. Synthetic Oils
3. Semi-synthetic oils
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Oil Properties
1. Viscosity
2. Anti Oxidation
3. Sealing
4. Cleaning
5. Prevent of foaming.
6. Oil thermal properties
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ENGINE LUBRICATION SYSTEMS
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PURPOSE AND FUNCTION
▣ The primary function of the engine lubrication system is to maintain a positive
and continuous oil supply to the bearings. Engine oil pressure must be high
enough to get the oil to the bearings with enough force to cause the oil flow
that is required for proper cooling.
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NORMAL OIL PRESSURE
✓ The normal engine oil pressure range is from 10 to 60 PSI (200 to 400 kPa) or 10
PSI per 1000 engine RPM.
✓ It is normal to see the following:
✓ Higher oil pressure when the engine is cold due to the oil being cold and at a higher
viscosity Lower oil pressure when the engine is at normal operating temperature due
to the oil becoming thinner even though it is multi-viscosity oil.
✓ Lower oil pressures at idle and higher pressures at higher engine speeds because oil
pumps are “positive displacement” pumps.
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NORMAL OIL PRESSURE
▣ The relatively low engine oil pressures obviously could not support these high
bearing loads without hydrodynamic lubrication. Oil pressure measurements
only show the oil pump pressure and not the pressure created between the
bearings and the crankshaft journal due to hydrodynamic forces.
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Wet Sump lubrication system
1. Oil Sump
2. Oil Strainer
3. Oil Pump
4. Oil relief valve
5. Oil filter
6. Oil Galleries
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Oil Sump
▣ What is the purpose of a windage tray?
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Oil Strainer
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Oil Pump
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Oil Pump
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Oil Pump
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FACTORS AFFECTING OIL PRESSURE
▣ Oil pressure can only be produced when the oil pump has a capacity larger
than all the “leaks” in the engine.
▣ Leaks..
▣ Oil pump capacity.
▣ Viscosity of the engine oil.
NOTE: A clogged oil pump pickup screen can cause lower than normal oil pressure
because the amount of oil delivered by the pump is reduced by the clogged screen.
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Journal Bearing
▣ Why excessive bearing clearances will decrease oil pressure??
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Pressure Regulator
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Oil Filter
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Oil Filter
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Oil Filter
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Oil Filter
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OIL COOLERS
▣ To control oil temperature, many diesel, high-performance, and super- or
turbocharged engines have an external engine oil cooler.
▣ Oil temperature should be:
▣ Above 212°F (100°C) to boil off any accumulated moisture
▣ Below 280°F to 300°F (138°C to 148°C)
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Oil Gallaries
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Oil Gallaries
▣ Oil is sent to the rocker arms on this Chevrolet V-8 engine through the hollow
pushrods. The oil returns to the oil pan through the oil drainback holes in the
cylinder head.
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OIL DIPSTICK
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OIL DIPSTICK
What Will Happen When Oil Level Is Below Min & Up Max?
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OIL PRESSURE INDICATOR
Warning light PRESSURE GAUGES
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BASIC LUBRICATION SYSTEM
DIAGNOSIS AND SERVICE
▣ Other than engine destruction, engine lubrication problems can cause other
engine concerns, such as noise, exhaust smoke, and the need to add oil to the
crankcase.
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OIL CONSUMPTION
What The Reasons Of Excessive Oil Consumption ??
✓ Worn Piston Rings, Valve Seals, Or Valve Guides
✓ Cam Cover Gasket, Head Gasket, Oil Filter, Front And Rear Seals, Oil Pan Gasket
✓ Positive Crankcase Ventilation (PCV) System
✓ External Oil Cooler
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POSITIVE CRANKCASE VENTILATION
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SLUDGE
▣ Excessive sludge can also be caused by a
plugged PCV hose or valve. Because the PCV
purges the crankcase of vapor and moisture, a
plugged system will allow condensation to
build up and contaminate the oil.
▣ If the sludge on the filler cap is white, suspect a
blown head gasket. The whitish gel is caused by
coolant mixing with the oil.
▣ Often, sludge can be removed by flushing the
system. However, if the buildup is great, the
engine should be torn down and cleaned.
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FLUSHING THE SYSTEM
▣ Flushing the lubrication system periodically is recommended by some
manufacturers. However, there are others that do not recommend flushing the
engine.
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How Engine Lubrication System Works
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OIL CHANGING
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Dry Sump Lubrication System
▣ Used with high speed vehicles
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Dry Sump Lubrication System
ADVANTAGES
1. A shallow oil pan allows the engine to be mounted lower in the vehicle to improve
cornering.
2. The oil capacity can be greatly expanded because the size of the reservoir is not
limited. A larger quantity of oil means that the oil temperature can be controlled.
3. Allows the vehicle to corner and brake for long periods, which is not able to be
done with a wet sump system due to the oil being thrown to one side and away
from the oil pickup.
4. Allows the engine to develop more power as the oil is kept away from the moving
crankshaft.
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Oil Pump
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COOLING SYSTEM
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PURPOSE AND FUNCTION
▣ Today’s engines create a tremendous amount of
heat.
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PURPOSE AND FUNCTION
▣ Today’s engines create a tremendous amount of
heat.
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How Car Cooling System Works
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LOW-TEMPERATURE ENGINE PROBLEMS
▣ To reduce cold engine problems and to help start engines in cold climates,
most manufacturers offer block heaters as an option. These block heaters are
plugged into household current (110 volts AC) and the heating element warms
the coolant.
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HIGH-TEMPERATURE ENGINE PROBLEMS
▣ Maximum temperature limits are required to protect the engine. Higher than
normal temperatures can cause the following engine-related issues.
1. High temperatures will oxidize the engine oil and Higher than normal
temperatures will also cause the oil to become thinner (lower viscosity than
normal).
2. Thinned oil will also get into the combustion chamber by going past the piston
rings and through valve guides to cause excessive oil consumption.
3. Detonation (also called spark knock or ping) to occur.
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COOLANT
▣ Coolant Water + Antifreeze
▣ If water is boiled Air Pocket
▣ If water is frozen Volume Increase
▣ Corrosion Inhibitors
▣ Coolant Color – Change
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THERMOSTAT
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THERMOSTAT
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COOLING SYSTEM OPERATION
▣ Air Cooled Engine
□ Simple
□ No moving Parts
□ No maintenance
□ No Liquid & Leak
□ Low Efficiency
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WATER GALLERIES
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WATER GALLERIES
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WATER GALLERIES
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WATER PUMP
Mechanical Pump
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WATER PUMP
▣ Some engines have an electric water pump for the
engine cooling system.
Electric Pump
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RADIATOR
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RADIATOR
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RADIATOR
▣ Transmission Cooler
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PRESSURE RADIATOR CAP
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PRESSURE RADIATOR CAP
Use caution when opening a hot radiator. Always squeeze the top
hose first to make sure that the cooling system is not under
Safety pressure (Figure 14.56). If coolant is heated to 240°F (116°C) and the
radiator cap is removed, the coolant temperature will be well above
Note its unpressurized boiling point. It will boil violently and someone
could be badly scalded by the exploding coolant!
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EXPANSION TANK
▣ CLOSED-COOLING SYSTEMS
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EXPANSION TANK
▣ CLOSED-COOLING SYSTEMS
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EXPANSION TANK
▣ OPENED-COOLING SYSTEMS (SURGE TANK)
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EXPANSION TANK
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HOSES
▣ Why are hoses made of rubber & reinforced ??
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3
Water Outlet
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4
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HEARER SYSTEM
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FAN
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ELECTRIC FAN
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TEMPERATURE SENSORS
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Fuel System
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110
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TURBO &
SUPER CHARGER
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TURBOCHARGERS
TURBOCHARGER
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TURBO CHARGER
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TURBO CHARGER
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TURBO CHARGER
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TWIN TURBO
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SEQUENTIAL TURBO
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SUPERCHARGERS
SUPERCHARGER
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SUPERCHARGER
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