DAF LF45, LF55 Series. Manual - part 160

©

 200505

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BE/CE engine cooling system

DIAGNOSTICS

ΛΦ45/55 series

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3. BE/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

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 200505

BE/CE engine cooling system

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ΛΦ45/55 series

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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 the 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 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

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DIAGNOSTICS

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SYMPTOM: EXTERNAL COOLANT LEAKAGE

Possible cause

Remedy

Coolant hoses defective

Check the coolant hoses

Coolant pipes defective

Check the 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

Inspect the oil cooler. Pressure-test if necessary

Defective pressure cap

Check the pressure cap. Pressure-test if 

necessary

Heater leaking

Check the heater hoses

SYMPTOM: INTERNAL COOLANT LEAKAGE

Possible cause

Remedy

Defective cylinder head gasket

Check the cylinder head gasket

Cracked cylinder head or cylinder block

Check the cylinder head and cylinder block for 

internal cracks. Pressure-test if necessary

Defective compressor cylinder head gasket

Replace the compressor cylinder head gasket

Defective oil cooler

Check whether there is coolant in the lubrication 

system

Defective expansion plugs in cylinder block or 

cylinder head

Replace the leaking expansion plug(s)

DIAGNOSTICS

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©

 200505

BE/CE engine cooling system

1

ΛΦ45/55 series

2