ENGINE LUBRICATION &
COOLING SYSTEMS
SECTION
LC
CONTENTS
PRECAUTIONS AND PREPARATION............................1
Liquid Gasket Application Procedure ..........................1
Special Service Tools ..................................................2
ENGINE LUBRICATION SYSTEM..................................3
Lubrication Circuit ........................................................3
Oil Pressure Check......................................................3
Oil Pump ......................................................................4
Oil Cooler .....................................................................7
Oil Jet...........................................................................7
Turbocharger ...............................................................8
ENGINE COOLING SYSTEM..........................................9
Cooling Circuit .............................................................9System Check..............................................................9
Water Pump ...............................................................10
Thermostat .................................................................12
Radiator .....................................................................14
Re®lling Engine Coolant ............................................14
Cooling Fan (Crankshaft driven) ...............................15
Cooling Fan (Motor driven)........................................15
Radiator (Aluminum type) ..........................................16
Overheating Cause Analysis .....................................20
SERVICE DATA AND SPECIFICATIONS (SDS)..........21
Engine Lubrication System ........................................21
Engine Cooling System .............................................21
LC
Overheating Cause Analysis
Symptom Check items
Cooling
system parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
Ð Thermostat stuck closed Ð
Damaged ®nsDust contamination or paper
clogging
Mechanical damage
Clogged radiator cooling tubeExcess foreign material (rust,
dirt, sand, etc.)
Reduced air ¯owCooling fan does not operate
ÐÐ Fan coupling does not operate
High resistance to fan rotation
Damaged fan blades
Damaged radiator shroud Ð Ð Ð
Improper coolant mixture ratio Ð Ð Ð
Poor coolant quality Ð Ð Ð
Insufficient coolantCoolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deteriora-
tion or improper ®tting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Over¯owing reservoir tankExhaust gas leaks into cooling
systemCylinder head deterioration
Cylinder head gasket deteriora-
tion
Except
cooling
system parts
malfunctionÐ Overload on engineAbusive drivingHigh engine rpm under no load
Driving in low gear for extended
time
Driving at extremely high speed
Powertrain system malfunction
Ð Installed improper size wheels
and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air ¯owBlocked bumper Ð
Ð Blocked radiator grilleInstalled car brassiere
Mud contamination or paper
clogging
Blocked radiator Ð
Blocked condenser
Ð
Installed large fog lamp
ENGINE COOLING SYSTEM
LC-20
