DAF CF65, CF75, CF85 Series . Manual - part 187

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3-1

CE-engine cooling system

DIAGNOSTICS

ΧΦ65/75/85 series

2

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3. CE-ENGINE COOLING SYSTEM

3.1 INTRODUCTION

If there is a fault in the system, it is usually 
detected by the electronic unit in the form of a 
fault code. This fault code can be read out using 
DAVIE. The fault-finding table contains possible 
causes of symptoms not detected by the 
electronic unit. 

DIAGNOSTICS

3-2

©

 200351

CE-engine cooling system

1

ΧΦ65/75/85 series

2

3.2 FAULT-FINDING TABLE

SYMPTOM: ENGINE TEMPERATURE INCREASES

Possible cause

Remedy

Incorrect injectors installed

Check whether the correct injectors have been 
installed

Inlet system failure

Check the inlet system.

Lubrication system failure

Check the lubrication system

Incorrect poly-V-belt tension

Check the poly-V-belt tensioner or replace the 
poly-V-belt

Insufficient coolant

Check the coolant level. Top up if necessary

Coolant hose torn or clogged

Check coolant hoses

Air cooler and cooling system radiator fouled

Check/clean the air cooler and cooling system 
radiator

Wastegate setting is too high.

Check the wastegate setting

Air hose from the turbocharger housing to the 
wastegate diaphragm leaks or is not connected.

Check the air hose. Replace if necessary.

Incorrect or malfunctioning pressure cap

Check the pressure cap

Thermostat opens insufficiently or not at all

Check the thermostat and its operation

Coolant filter fouled

Check the coolant filter Replace, if necessary, and 
clean the cooling system

Coolant pump defective

Check the coolant pump shaft, bearings and 
impeller. Replace the coolant pump, if necessary

Viscous fan defective

Check operation of the viscous fan

Poor fuel quality

Drain fuel, flush fuel system, replace the fuel filters 
and fill fuel tank with fuel

SYMPTOM: EXTERNAL COOLANT LEAKAGE

Possible cause

Remedy

Coolant hoses defective

Check coolant hoses

Coolant pipes defective

Check coolant pipes

Radiator leaking

Check the radiator Pressure-test if necessary

Coolant pump leaking

Check coolant pump If necessary, measure 
bearing play

Defective oil cooler

Check the oil cooler. Pressure-test if necessary

Defective pressure cap

Check the pressure cap. Pressure-test if 
necessary

Heater leaking

Check the heater hoses

Leaking connection between coupling and water 
pipe

Check connection between water pipe and 
coupling for damage.
Replace the O-rings

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CE-engine cooling system

DIAGNOSTICS

ΧΦ65/75/85 series

2

1

SYMPTOM: INTERNAL COOLANT LEAKAGE

Possible cause

Remedy

Defective cylinder head gasket

Check the cylinder head gasket

Cracked cylinder heads or cylinder block

Check the cylinder heads and cylinder block for 
internal cracks. Pressure-test if necessary

Leaking injector sleeves

Check the cylinder heads Pressure-test if 
necessary

Defective compressor cylinder head gasket

Replace compressor cylinder head gasket

Defective oil cooler

Check whether there is coolant in the lubrication 
system

Defective freeze plugs in tappet area (cylinder 
block) or at the top of the cylinder heads

Replace freeze plug(s)

DIAGNOSTICS

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©

 200351

CE-engine cooling system

1

ΧΦ65/75/85 series

2