Mystery intermittant vibration

[idlerider]

I’m getting a vibration/judder that seems to be from the drivetrain. It varies between not there at all and quite pronounced, often set off by the road surface. Left or right cornering makes no difference and appears to be most pronounced at about 60 mph.

Can anyone tell me what the cause might be?

 

[M80]

Check to see if it might be rev related.
The TC can do this, in my experience between 1,800 and 2,000 revs. I've read the lock up solenoid can be the culprit.

 

[idlerider]

TC? Cracked it - torque converter! Doh.

 

[AlanGunn]

When the tc starts to fail (lockup clutches) you will get a vibration when sort of coasting but you will see the rev counter fluctuate as well.

 

[brandwooddixon]

Does the vibration change if you change down a gear or two? If not then it's unlikely to be the torque converter.
Look at possible issues with rear suspension, wheels or tyres as well. For example, if it's triggered by road surface then there could be some resonant frequency hit with a weak rear shock absorber.

 

[AlanGunn]

If it is the tc lockup clutches the vibration will go away if you put your foot down or take your foot off.

 

[idlerider]

I'm grateful to everyone who's responded and have tried to test all your suggestions, with the following observations:
engine revs appear to make no difference, nor does gear changing;
rev counter does not fluctuate;
acceleration or braking produces no change.
I'm coming to suspect that 'brandwooddixon' may have the right answer - rear shock absorber(s).

 

[Wighty]

I’m getting a vibration/judder that seems to be from the drivetrain. It varies between not there at all and quite pronounced, often set off by the road surface. Left or right cornering makes no difference and appears to be most pronounced at about 60 mph.

Can anyone tell me what the cause might be?

What mileage are you on buddy ?
North of 100k might be worth changing engine and transmission mounts.

 

[idlerider]

What mileage are you on buddy ?
North of 100k might be worth changing engine and transmission mounts.

Just got there last month!

 

[M80]

These can be a bitch.

Drop the prop shaft, looking for clicky uj or bearing wear.
Be sure to mark meeting flanges prior to dropping.

 

[Stalky]

I have the same judder, which comes while gently accelerating. Also a 'BRRRRR" vibration, which appears for a few seconds every now and then on the freeway while doing around 110 KM/H. I spoke to the workshop foreman at the local Merc dealership (Very fancy place!) and he immediately pointed to the Torque Convertor (TC) and gave me an eye-watering price for the part! This was with reference to the 'judder'. The other vibration on the freeway, he just shrugged his shoulders! No idea, he said. HELP!

 

[Stalky]

The above problems all on my recently purchased W212 E350 CDI with 7222.9 G-Tronic 7 speed box. Current mileage is 244,000 Kilometers.
I dropped the prop-shaft and replaced the center hanger and bearing. The old one still looked OK, and it has made no difference.

 

[Stalky]

Follow up :- I spent the afternoon scanning every facet of the W212 E350 CDI. No codes! Then test drive with scanner monitoring the gearbox. The Torque Converter NEVER shows 'Locked Up', Only 'Open' when parked idling, and always 'Slipping' when driving at all speeds, foot on throttle or off.
Any suggestions from the 'Old Merc Boys"? Help!
If I switch off the ESP, it seems to stop the 'BRRRRRRRR' issue. TC still 'slipping' all the time. I hope that I don't have to pay for a new TC! Above my pay grade! The vibration seems to point to a possible intermittent wiring problem to the wheel speed sensors, which I read of elsewhere. Very tricky to find the culprit wire.