Wierd vibrations

[minyak]

Hi all,

Never experienced this before, but on 2 separate occasions while travelling at around 30-50mph on I'm sure fairly smooth roads, my cars body started to vibrate, shudder for around half to a minute and then went away. The engine seem to run fine, not too sure what is the source. It felt wierd as if we were on a flight going thru mild turbulence...could it be wheel misaligning, exhaust joint failing or something. Its a C220 CDi estate (W203). But instinct tells me that the source is something from underneath, but what could it be?? help please
Thanks.

 

[miro]

Hi all,

Never experienced this before, but on 2 separate occasions while travelling at around 30-50mph on I'm sure fairly smooth roads, my cars body started to vibrate, shudder for around half to a minute and then went away. The engine seem to run fine, not too sure what is the source. It felt wierd as if we were on a flight going thru mild turbulence...could it be wheel misaligning, exhaust joint failing or something. Its a C220 CDi estate (W203). But instinct tells me that the source is something from underneath, but what could it be?? help please
Thanks.

Wheel bearing ?

 

[Voltan]

Assuming you are sure that it is not road induced, my guess is it was engine related. You know, like the engine faltered intermittently for a brief moment, before singing along happily again. Do check your fuel and fuel system thoroughly. Check for fuel bugs that may grow in your tank- if so remove and clean the tank plus use the diesel debugging chemical. Or check for excessive water in fuel - drain out at the water trap until you see just fuel draining out.

 

[Ian B Walker]

Things I would check are engine mountings, gearbox mountings, Propshaft doughnuts, wheel balancing, torsion bar bushes, shock absorbers.

 

[grober]

Beach Boys required I think!

Have you tried playing track1 DISC 2 of the Beach Boys Platinum Collection when this problem occurs? Sorry couldnt resist! I am veering towards Voltans expanation since the other mechanical faults should be consistently induced every time you drive at 30-50mph. Is the engine hot or cold when this happens? How many miles has the car done in total . If you try to accelerate out of the 30-50 zone while its happening what happens. The other possibility that occurs is some sort of intermittant electrical fault causing the engine to lose power. How does the instrument panel look when all this is happening. Is there a particular additional electrical device operating when this fault occurs which might be bringing down the voltage supply. See I wasnt just kidding about the Beach Boys?

 

[minyak]

Hi,

So far engine and electricals wise, no strange messages on the on-board computer during the shudder, I am regular on the diesel debugging/fuel additive, also dont think its trapped moisture. It happens when the engine is well heated up not cold. The car has done in excess of 100000 miles already, been serviced on time etc...but due for next service real soon. Only other device that runs during this time is the CD player, nothing else. Could be wheel bearing or some mounting as some of you said. I will send it off to the works soon. Thanks.

 

[grober]

Ingress of water?

The fact you car has done 100,000 miles plus does make the possibility of some sort of mechanical fault more likely, as suggested by some forum members. As I said I am puzzled by its intermittant nature. If its engine or electrics related it may show up as a stored fault/s when MB interogate the ECU when you next get it serviced. Only other thing I could think of was ingress of water to some electrical circuitry/ fuses. For example there was a post where the lid of the fusebox of forum members car wasnt sealing allowing water to seep in. This gave rise to strange faults. Did the fault occur during wet weather or after driving thro standing pools of water? Tho again I guess that would show up on your dashboard display. This takes us back to fuel. Does it happen when you are low on fuel or just performed a violent manouevre, heavy braking, cornering,acceleration- anything to stir up the tank contents. Have you filled up from any fuel pump you might regard as "suspect" recently. Fuel additives will only compensate for a certain level of fuel contaminant. Just a few thoughts.

 

[Muller]

Vibrations also on my merc

I had exactly the same problem, with the whole body of the car vibrating, it turned out to be the MAS sensor, as the engine pulled under load, the whole car would shake, very noticeably

Ryan