COOLING(H4SO) > Engine Cooling System Trouble in General

INSPECTION

Trouble

Possible cause

Corrective action

Overheating

a. Insufficient engine coolant

Replenish engine coolant, inspect for leakage, and repair it if necessary.

b. Loose timing belt

Repair or replace timing belt tensioner.

c. Oil on drive belt

Replace.

d. Malfunction of thermostat

Replace.

e. Malfunction of water pump

Replace.

f. Clogged engine coolant passage

Clean.

g. Improper ignition timing

Inspect and repair ignition control system.

h. Clogged or leaking radiator

Clean, repair or replace.

i. Engine oil mixed in engine coolant

Replace engine coolant.

j. Air/fuel mixture ratio too lean

Inspect and repair the fuel injection system.

k. Excessive back pressure in exhaust system

Clean or replace.

l. Insufficient clearance between piston and cylinder

Adjust or replace.

m. Slipping clutch

Correct or replace.

n. Dragging brake

Adjust.

o. Defective radiator fan

Inspect the radiator fan relay, engine coolant temperature sensor or fan motor and replace them.

Over-cooling

a. Ambient temperature extremely low

Partly cover radiator front area.

b. Defective thermostat

Replace.

Engine coolant leaks

a. Loosened or damaged connecting units on hoses

Correct or replace.

b. Leakage from water pump

Replace.

c. Leakage from water pipe

Correct or replace.

d. Leakage around cylinder head gasket

Retighten cylinder head bolts or replace gasket.

e. Damaged or cracked cylinder head and cylinder block

Correct or replace.

f. Damaged or cracked thermostat case

Correct or replace.

g. Leakage from radiator

Correct or replace.

Abnormal noise

a. Defective drive belt

Replace.

b. Defective radiator fan

Replace.

c. Defective water pump bearing

Replace water pump.

d. Defective water pump mechanical seal

Replace water pump.