OM603 Noise cyl 1 - PeachParts Mercedes-Benz Forum

grahamk · #1 12-14-2007, 04:09 PM

Hi,
I live in France and I have a 1995 S Class W140 S350 I am very happy with except for one thing.
This is the third engine in this car, I replaced the original 3.5 turbo diesel with used the 3 liter turbo diesel. It performed excellently for about 20 000 Km and now has developed a very nasty ticking noise.
To find the cause I have done the following:

Checked chain stretch – OK
Checked hydraulic valve lifters – OK
Checked injection timing – OK
Checked Injectors – OK
Checked vacuum pump – OK

With a special automotive stethoscope I have found that the sharp metal ticking times to the valve train and comes from cylinder nr 1 it is loudest when placing the stethoscope on the fuel line to injector number 1 (very loud ) Fuel additive to raise the cetane number had no effect, adding automatic gearbox oil (half liter, advised for faulty hydraulic lifters) no effect. The ticking is least when running stationary and gets louder when accelerating.

My remaining options are, can piston be touching the prechamber nozzle, is something lose in the prechamber, pre-ignition because of deposits in prechamber on glowplug.

Engine runs very even, no smoke (Black blue white or other color) uses no oil, runs economical, temperature is normal, power is OK

SO WHAT CAN IT BE??? Please help me , if I take it to the Mercedes garage they are going to start taking the head of and renewing everything and it is going to cost me an absolute fortune. ( Mercedes service stinks here in France. The Mercedes cars are OK but sevice is rubbish)

I would be VERY grateful for any suggestion. ( Except putting a match to it, or running it of a cliff)

Regards Graham;