R 350 CDI, black smoke, jerky at low revs, soot on exhaust, occasional limp mode

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Thanks again Supernoodle really helpful - definitely "hesitation and surging" is a much better description of what I am experiencing - as mentioned only between 1000 - 2000 revs... so the actuator looks to be the most likely culprit - not sure if I am brave enough to try to swap the actuator out so I guess a reluctant trip to my garage for a more detailed look is the way to go... though they will probably tell me it's a new turbo...
I did have a DPF fault before - the garage removed it and cleaned it and it seemed to be fine. Clearly there is something else going on which caused that DPF fault initially - so I hope that by not dealing with the root cause they haven't screwed up the DPF again as they are expensive...
Why not buy a refurbed exchange actuator form TurboVanes, get your garage to swap over (I did mine in less than 30 mins), make sure you get the old one back so you send it to TurboVanes to get your deposit back. That you avoid the garage trying to do any 'diagnostics' on the issue.
 
Larkone - great advice - the swap doesn't look overly complicated - just rather cramped - so may give it a go myself... thanks again.
 
When i changed my turbo i took the old one apart, it was really coked up badly, as for the variable vanes, you have the circular plate and then there is a rod which goes through the plate for each one, on one side the vane, on the other the arm that turns it in the sprocket.

The holes that these rods go through were the main issue for mine, they were really badly coked up in there and making it very hard to turn the vanes, not all but a couple which was difficult by hand. Combine several of these at the same time and the actuator will struggle and stick on its movement.

I would agree with the previous posts, take it off and send it off for a refurb or replace it ( not a difficult job to do)TRB.png
 
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Thanks Unclebuck - I'll give it a go...
 
Do you guys recommend against bothering to clean it then?

I’d be over the moon if this juddering was resolved.

@npritch is yours intermittent too?
 
I just removed the air intake Y pipe to check which actuator to order - I noticed a small pool of oil where the pipe goes into the turbo - is that usual? or would that indicate that the PCV valve needs replacing... I ask because it would probably be sensible to do both at the same time - however getting at the PCV valve looks pretty hard on an R class - do the windscreen wipers need to be taken off first? Thanks in advance.
 
Maybe that’s where mine is headed, but sometimes it goes away for a while for me, rarely when cold. Or, they could be totally different issues!

Really curious to open up the actuator and have a look, though.
 
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.
 
I'm afraid I don't know Teddy - they said it was the lower one - and not easy to spot - until they did the boost test...
 
Maybe that’s where mine is headed, but sometimes it goes away for a while for me, rarely when cold. Or, they could be totally different issues!

Really curious to open up the actuator and have a look, though.
Page 1 of this link was my actuator take apart buddy , I think it’s worth doing
 
When i changed my turbo i took the old one apart, it was really coked up badly, as for the variable vanes, you have the circular plate and then there is a rod which goes through the plate for each one, on one side the vane, on the other the arm that turns it in the sprocket.

The holes that these rods go through were the main issue for mine, they were really badly coked up in there and making it very hard to turn the vanes, not all but a couple which was difficult by hand. Combine several of these at the same time and the actuator will struggle and stick on its movement.

I would agree with the previous posts, take it off and send it off for a refurb or replace it ( not a difficult job to do)View attachment 119017
Have you seen the result of this thread buddy , one of the same fault codes as your p0299
 
Page 1 of this link was my actuator take apart buddy , I think it’s worth doing
Thank you - were you getting light juddering/hesitation at ~1500rpm, too?

Mine is intermittent - I just popped out for 1/2 hour and no sign of it.

No codes either.

I'm inclined to think that I have a very small air leak.
 
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Thank you - were you getting light juddering/hesitation at ~1500rpm, too?

Mine is intermittent - I just popped out for 1/2 hour and no sign of it.

No codes either.

I'm inclined to think that I have a very small air leak.
No I was getting limp mode (I think , it was a while ago :rolleyes:) , I just meant it’s an easy diy job that costs nothing to open and clean the actuator)
 
Hey @npritch or anyone else, any rough idea of how much an indie would charge to do a boost/smoke/leak test?

I've never had one done before.
 
Hi Teddy - I think they ran a diagnostic - the fault codes showed a turbo boost problem - which I assume wouldn't be detected with a smoke test - but only with a boost test. The part was just over £100 and the whole bill inc. VAT came to just over £200... hope that helps?
 
Hey @npritch or anyone else, any rough idea of how much an indie would charge to do a boost/smoke/leak test?

I've never had one done before.
Will let you know tomorrow when I am finally allowed out to pick mine up.
 

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