4.1.4. Diagnostics and troubleshooting
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Complaints
Possible causes
Corrections
1. Engine overheating
•
Lack of coolant
•
Replenish coolant
•
Radiator cap pressure
•
Replace cap
valve spring weakened
•
Fan belt loosened or
•
Adjust or replace fan belt
broken
•
Fan belt fouled with oil
•
Replace fan belt
•
Thermostat inoperative
•
Replace thermostat
•
Water pump defective
•
Repair or replace
•
Restrictions in water
•
Clean radiator and water
passages due to deposit
passages
of scales
•
Injection timing incorrect
•
Adjust injection timing cor
rectly
•
Restriction in radiator
•
Clean exterior of radiator
core
•
Gases leaking into water
•
Replace cylinder head
jacket due to broken cyli
gasket
nder head gasket
2. Engine overcooling
•
Thermostat inoperative
•
Replace thermostat
•
Ambient temperature
•
Install radiator curtain
too low
3. Lack of coolant
•
Radiator leaky
•
Correct or replace
•
Radiator hoses loosely
•
Retighten clamps or
connected or damaged
replace hoses
•
Radiator cap valve spring
•
Replace cap
weakened
•
Water pump leaky
•
Repair or replace
•
Heater hoses loosely
•
Tighten or replace hoses
connected or broken
•
Cylinder head gasket
•
Replace cylinder head
leaky
gasket
•
Cylinder head or cylinder
•
Replace cylinder head
block cracked
block
4. Cooling system
•
Water pump bearing
•
Replace bearing
noisy
defective
•
Fan loosely fitted or bent
•
Retighten or replace fan
•
Fan out of balance
•
Replace fan
•
Fan belt defective
•
Replace fan belt