Symptom Charts

SYMPTOM CHART, LEAKS

Symptom	Possible Cause	Action
External coolant leaks	Damaged hose(s) Damaged expansion tank Damaged radiator Leaking seals/gaskets Cracked/damaged casings	Refer to the relevant section of the workshop manual and test the cooling system for leaks
Internal coolant leaks Note: This may be indicated by the production of white smoke from the exhaust	Leaking seals/gaskets Cracked/damaged casings	Refer to the relevant section of the workshop manual and test the cooling system for leaks
Engine overheats	Insufficient coolant Insufficient oil Pressure cap fault Thermostat not opening Coolant pump failure Cooling fan failure	Refer to the relevant section of the workshop manual and test the cooling system for leaks Check the engine oil Test the operation of the thermostat Test the operation of the coolant pump Test the operation of the cooling fan
Engine takes too long to reach operating temperature	Thermostat stuck open	Test the operation of the thermostat
External oil leaks	Gaskets Seals Oil pipes Oil filter Oil cooler Damaged/cracked casings Crankcase ventilation system Piston ring blow-by	Clean and confirm the area of the leak. Check the visual condition of oil carrying components. Check the crankcase ventilation system. Carry out a compression test, Refer to Pinpoint Test A .
Internal oil leaks (leaks into coolant or combustion chamber) Note: This may be indicated by the production of blue smoke from the exhaust	Gaskets Seals Damaged/cracked casings Worn valve guides Worn cylinder bores/pistons Broken piston rings	Check for traces of oil in the coolant. Check for evidence of oil in the combustion chambers (deposits on the glow plugs, etc). Confirm oil consumption and vehicle usage with the owner/driver. Carry out an oil consumption test, Refer to Pinpoint Test B .

NOTE: As the checks suggested here are open to interpretation, they should be used as a guide only. Descriptions of noises, etc, are in general terms, so depend on a degree of experience on the part of the technician.

SYMPTOM CHART, NVH

Symptom	Possible Cause	Action
Rattle/ticking from top of engine	Valve gear noise Camshaft bearing noise Timing belt noise Tensioner noise Vacuum pump noise High pressure fuel pump noise	Check the engine oil pressure, Refer to Pinpoint Test C . Check the function of the hydraulic tappets and the camshaft condition. Check the camshaft bearings. Check the timing belt and tensioner Check the vacuum pump Check the high pressure fuel pump
Growl from top of engine	High pressure fuel pump belt noise High pressure fuel pump belt tensioner noise	Check the high pressure fuel pump belt Check the high pressure fuel pump belt tensioner
Squeaking/Creaking/Squeal from front of engine	Auxiliary drive belt Auxiliary drive belt tensioner Driven components on auxiliary drive belt	Check the auxiliary drive belt Check the auxiliary drive belt tensioner Check the driven components
Whine/Slap/Growl from front of engine	Auxiliary drive belt Auxiliary drive belt tensioner Driven components on auxiliary drive belt Timing belt noise Timing belt tensioner noise	Check the auxiliary drive belt Check the auxiliary drive belt tensioner Check the driven components Check the timing belt Check the timing belt tensioner
Knock from lower half of engine (often worse with a cold engine)	Piston slap Piston pin noise Connecting rod bearing noise	Check the engine oil pressure, Refer to Pinpoint Test C . Check piston, cylinder bore, piston pin and connecting rod bearing for excess wear
Knock/Rumble from lower half of engine (often worse on overrun)	Main bearing noise	Check the engine oil pressure, Refer to Pinpoint Test C . Check connecting rod bearing for excess wear
Misfire/Rough running	Engine management system Fuel charging and controls Exhaust gas recirculation (EGR) system Burnt/sticking valves Worn valve guides Worn cylinder bores/pistons Broken piston rings Damaged/cracked casings	Using the manufacturer approved diagnostic system, check the Engine Control Module (ECM) for related DTCs and refer to the relevant DTC index Carry out a compression test, Refer to Pinpoint Test A . Check for excess wear in engine components