Over-heating | a. Insufficient engine coolant | Replenish engine coolant, inspect for leakage, and repair it if necessary. |
b. Defective thermostat | Replace. |
c. Malfunction of water pump | Replace. |
d. Clogged engine coolant passage | Clean. |
e. Improper ignition timing | Inspect and repair ignition control system. Basic Diagnostic Procedure |
f. Clogged or leaking radiator | Clean, repair or replace. |
g. Defective radiator cap | Replace. |
h. Improper engine oil in engine coolant | Replace the engine coolant. If ineffective, check, repair or replace engine components. |
i. Air/fuel mixture ratio too lean | Inspect and repair the fuel injection system. Basic Diagnostic Procedure |
j. Excessive back pressure in exhaust system | Clean or replace. |
k. Insufficient clearance between piston and cylinder | Adjust or replace. |
l. Slipping clutch | Repair or replace. |
m. Dragging brake | Adjust. |
n. Malfunction of 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 | Repair or replace. |
b. Leakage from water pump | Replace. |
c. Leakage from water pipe | Repair or replace. |
d. Leakage around cylinder head gasket | Retighten cylinder head bolts or replace cylinder head gasket. |
e. Damaged or cracked cylinder head and cylinder block | Repair or replace. |
f. Damaged or cracked thermostat cover | Repair or replace. |
g. Leakage from radiator | Repair or replace. |
Noise | a. Defective radiator fan | Replace. |
b. Defective water pump bearing | Replace water pump. |
c. Defective water pump mechanical seal | Replace water pump. |