Amcutler

Hi, I've just got myself a w211 e 320cdi and it has this annoying vibration that only seems to come when at motorway speeds and at constant throttle. If I let off or put on even a smidgen of gas it'll stop until I'm at constant speed again.

144k miles, auto, really good service history if it helps..

Any ideas or help is appreciated!
Thanks

Amcutler

I should also have said that it's coming from the rear left hand side as you sit I the car.

Nicuu

Strange. Mine does the vibration AND buzzing, but that's at low speed, with low throttle.

Don't know what could be wrong. How does the vibration appear?

wallfly54

You don't mention your model year, but if its a 2003, it could be glycol in the automatic transmission. I literally got my car back today from the dealership to fix this problem. I narrowly avoided a pooched transmission (I hope, as the tranny costs more than the car is worth!). They replaced the radiator, cooling lines between the transmission and the radiator and flushed the transmission 4 times. Total cost was around $2,500.

All vibrations, rumblings etc. seem to be gone now.

Check the other blogs. There were several TSBs from M-B on it. Here is an excerpt from the TSB:

Harsh Engagement Possibly Followed by Droning/Buzzing Noises During Light Acceleration
Between Engine Speed of 1200 – 2500 RPM

Model 203.040/061/064/065/081/084/261/264/281/284/740/747/764 Model 209.365/375/376/465/475 Model 211.065/070/076/083/265/283 Up to Production Date 09/2003


If you receive customer reports in the above model vehicles of humming/buzzing noises or noticeable harsh engagement during gentle acceleration between engine speed of 1200 – 2500 rpm; this may be caused by incomplete adaptation of the torque converter, the transmission (EGS) ECU software or glycol contamination of the automatic transmission fluid.

See the attached PDF.

Amcutler

Hi, thanks for the reply, it is a 2003. I've had a look through the history with car and its had a new converter and there's mention of changing pipes and transmission fluid so I think it's been done. The car changes gear smooth still and the vibration seems to be there when at lower rpm or constant speed but goes if you change speed even a tiny amount..
Thanks
Alan

sand8

Have you look at the engine shock mount (one on each side of the engine) and the transmission shock mount (one only)?