Puffs of Black smoke on acceleration, car jerky at low revs, soot around exhaust, occasional lapse into limp mode...

[Nickyp]

Thanks star - I had a quick look - but probably needs a proper smoke test?

 

[mioba]

The PCV is a painsteaking beach on the W251 because if its location. Working on that engine is hard work beecause many things are high up, and its very tight meaning sometimes (mostly) you are working blind by touch, needings mirrors and a back and arms long like a giraffe.
I think you would be better getting it done by an indy as you infer not being so hands on,....0

And the orange seal to the turbo should be a service item on these, if the oil had leaked down into the V, then it will kill your swirl flap motor.

 

[Nickyp]

Thanks Mioba - yes I think it might be a bridge too far - the actuator looks doable though... concerned by your last sentence though - the oil had pooled very slightly at the bottom of the intake to what I imagine you mean by the "swirl flap motor" - would that indicate a problem with the PCV?

 

[star]

Another cause could be the egr, guessing is going to cost you. A boost pipe and egr can give you a jerking engine.

 

[Nickyp]

Thanks Star. That's all I need....

 

[Nickyp]

Solved! Thanks to all for the help. It was (as some of you suggested) a split OSF lower boost hose - detected after a "boost test". Around £200 and I have my old car back - such a relief. Thanks again.

 

[mattkh]

Thanks for letting us know.
Very happy for you.

 

[sausage]

Good stuff.

 

[mioba]

Good one OP.
I also had a hose fail which lead to - running lean on bank one error code. Cant remember the code now.
But glad you all sorted.

 

[ashford charlie]

As someone with zero capabilities with regard to car mechanics, I've followed this post with interest. The support shown to the OP and the knowledge displayed is one of the reasons this website is so good. Well done all concerned.