Quick OM642 question.

KennyN

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As above people , I am experiencing a very slight vibration / buzzing sensation through the steering wheel when the car , CLS 2010, is idling at its fully warmed 600 rpm.

Car stationary , gearbox in any position , AC on / off , foot on /off the brake it make no difference to the vibration.

Increase the revs by the slightest (625) and the vibration stops , above tickover it is as smooth as ever . With the engine cover off and resting my hands on the airboxes i can feel the same vibration so i am 100% convinced it is engine related.

As i do very short journeys the car very seldom gets warm enough to idle at 600rpm but recently i have been using the car more allowing it to warm up properly and have noticed this above issue.

No fault codes on the Carsoft , mpg unaffected but still terrible , no unusual engine noises apart from the usual diesel mechanical mayhem.

Thoughts , is this normal or have i got yet more work / outlay ahead ?

Kenny
 
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M80

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I would say it's because your tickover is too low.
Mine ticks over at 680, the C320 was around 750 if memory serves.
 
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KennyN

KennyN

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I would say it's because your tickover is too low.
Mine ticks over at 680, the C320 was around 750 if memory serves.


The car has always sat at 600rpm when fully warmed up and the battery is happy , it starts at 1000 , drops to 800 after a few seconds where it sits until it warms up and settles at 600.

I have only recently noticed , had the car four years , this but it may be that they all do it and i am being over critical.

It is not intrusive at all but it is there non the less.

Kenny
 

Wighty

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I must admit that does sound low , I'll check mine when it's next warm .
 

John Laidlaw

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Most of the diesels I’ve had have sat 800 ish when warm- I’ve only had one Mercedes diesel mind and that was a hybrid so doesn’t count! I’ll check my Volvo later but iirc it’s also sitting 800 plus
 

Larkone

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Bearing going on one of the wheels on the auxiliary belt?
 

PB53CLS

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Kenny,mine does the same as yours!
 
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KennyN

KennyN

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Kenny,mine does the same as yours!

That's good to here , I will give the aux belt and pulleys a check over on my next day off just for piece of mind.

Kenny
 

malcolm210

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‘Yes, they all do it sir’

Seriously though when I bought my E350cdi two years ago the tickover when warm at 600rpm was as you describe a bit lumpy and certainly not what you’d expect and would smooth out as soon as the revs were increased

Wind the clock on two years and the use of BP fuel exclusively and with the odd dose of Millers diesel cetane enhancer the tick over is really smooth, I can only assume there was a build up of soot on the injector tips so nothing to worry about
 

malcolm210

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‘Yes, they all do it sir’

Seriously though when I bought my E350cdi two years ago the tickover when warm at 600rpm was as you describe a bit lumpy and certainly not what you’d expect and would smooth out as soon as the revs were increased

Wind the clock on two years and the use of BP fuel exclusively and with the odd dose of Millers diesel cetane enhancer the tick over is really smooth, I can only assume there was a build up of soot on the injector tips so nothing to worry about or elsewhere in the intake system
 
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