Cooling System Troubleshooting

SymptomProblemSolution

Engine Overheats

Lack of coolant in cooling system

Fill cooling system to proper level.

 

Radiator core dirty

Clean radiator as required.

 

Engine overloaded

Reduce engine load.

 

Too low crankcase oil level

Fill crankcase to proper oil level.

 

Loose or defective fan belt

Replace fan belt as required. Check belt tensioner. (See Section.)

 

Defective thermostat(s)

Test thermostat opening temperature; replace thermostats as required.

 

Damaged cylinder head gasket

Replace cylinder head gasket. See your John Deere engine distributor or servicing dealer.

 

Defective coolant pump

Replace coolant pump. See your John Deere engine distributor or servicing dealer.

 

Defective radiator cap

Replace radiator cap as required.

Coolant in Crankcase

Cylinder head gasket defective

Replace cylinder head gasket. See your John Deere engine distributor or servicing dealer.

 

Cylinder head or block cracked

Locate crack, repair/replace components as required.

 

Cylinder liner seals leaking

Remove and inspect cylinder liners. See your John Deere engine distributor or servicing dealer.

 

Leaking oil cooler

Pressure test oil cooler; repair/replace as required. See your John Deere engine distributor or servicing dealer.

 

Defective oil cooler O-rings

Remove and inspect oil cooler O-rings; replace as required. See your John Deere engine distributor or servicing dealer.

 

Faulty coolant pump seal; weep hole plugged; coolant leaking through bearing

Replace coolant pump seals. See your John Deere engine distributor or servicing dealer.

Coolant Temperature Below Normal

Defective thermostat(s)

Test thermostats; replace thermostats as required.

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