E350 driveline vibration.

[Swem]

I have a 2010 E350 convertible, with 145,000 miles and a generally comprehensive service history.

Having previously run completely smoothly, I now have a driveline vibration/rough running on start up and idle when cold. It gets worse when in gear, more so in drive than reverse.
Once the car has been driven and fully warmed through it disappears. But it is very noticeable when running poorly and certainly not like it was up to this point.

The engine mounts were replaced under warranty a couple of weeks ago having failed after being replaced 15,000 miles previously together with the gearbox mount - this has reduced the vibration to a degree but not eradicated it.

It's currently in with my usual and very good garage, they can't find anything obviouslywrong and have had overnight so from cold. The gearbox level is correct and the fluid looks healthy, although this hasn't been changed recently, and there are no engine or gearbox fault codes. The suggestion is that it could be engine related, possibly injectors? I have previously experienced an occasional slightly uneven idle, I had read that this could potentially be caused by a gearbox issue? This didn't create the vibration I'm currently experiencing.

I'm planning to sell the car having already bought it's replacement, so any suggestions or pointers would be gratefully received prior to the garage taking it apart!

Thanks.

Simon.

 

[Smiley]

From the symptoms you describe I would have thought that it is more likely to be engine related.
A couple of thoughts
1. a leaking injector which is dripping fuel into a cylinder overnight
2. a bit of valve seat degradation on one or more cylinders - as the head warms up it expands slightly and allows the valves to seat properly.
I had a 124 diesel years ago with similar symptoms to your car - replaced quite a lot of parts inc all injectors and no improvement - eventually concluded that it was valve seat wear in a rear (less well cooled) cylinder. The problems started at about 150k miles and did not get any worse over the next 180k miles
The risk is that you could spend a lot of money chasing the fault - in your situation I would sell the car with a declared fault - let someone else have fun with the parts bin.

 

[Swem]

From the symptoms you describe I would have thought that it is more likely to be engine related.
A couple of thoughts
1. a leaking injector which is dripping fuel into a cylinder overnight
2. a bit of valve seat degradation on one or more cylinders - as the head warms up it expands slightly and allows the valves to seat properly.
I had a 124 diesel years ago with similar symptoms to your car - replaced quite a lot of parts inc all injectors and no improvement - eventually concluded that it was valve seat wear in a rear (less well cooled) cylinder. The problems started at about 150k miles and did not get any worse over the next 180k miles
The risk is that you could spend a lot of money chasing the fault - in your situation I would sell the car with a declared fault - let someone else have fun with the parts bin.

Great thanks, sounds like the way to go then.
Much appreciated.