Replacing - Mercedes-Benz OM 457 LA Operating Instructions Manual

Troubleshooting
90
Problem
The exhaust fumes are
blue.
The exhaust fumes are
white.
The engine is "knock-
ing".
The engine is "knock-
ing".
There are abnormal
sounds.
Indicator lamp for
charge current lights
up.
Replacing the poly-V-belt
If the poly-V-belt is torn or shows damage
patterns, it must be replaced.
Possible causes/consequences and M Solutions
The oil level in the engine is too high; the crankcase ventilation
system is faulty; engine oil has entered the combustion chamber.
X
Adjust the oil level correctly.
X
Have the crankcase ventilation system checked at a qualified
specialist workshop.
Coolant is entering the combustion chamber.
X
Have a pressure loss test carried out at a qualified specialist
workshop.
The engine is misfiring.
X
Consult a qualified specialist workshop.
There is bearing damage.
X
Consult a qualified specialist workshop.
The air intake pipe and exhaust gas pipe are leaking, causing a
whistling noise.
X
Rectify the cause of the leak and, if necessary, replace gaskets.
The turbine or compressor wheel is scraping the housing; there are
foreign objects in the compressor or turbine housing; bearings
have seized on the rotating parts.
X
Have the exhaust gas turbocharger checked at a qualified spe-
cialist workshop.
The valve clearance is excessive.
X
Check and adjust the valve clearance.
The poly-V-belt is slipping.
X
Check that the poly-V-belt contact surfaces are not torn, dam-
aged, oily or glazed. Replace the poly-V-belt if necessary.
The poly-V-belt is slipping.
X
Check that the poly-V-belt contact surfaces are not torn, dam-
aged, oily or glazed. Replace the poly-V-belt if necessary.
G
WARNING
The tensioning device is spring-tensioned.
When it is loosened or tightened, there is a
risk of injury from crushing or entrapment in
pretensioned parts.