Vito Engine - grey heavy smoke

[GWhittell]

Pressure differentials idle vs boosting can permit leaking of oil (esp compressor) I think.

Useful to know!

I always approach things from an optimistic point of view so I would check the simpler (and usually) cheaper options first. Maybe a sensible approach would be to find an Indy with good knowledge of your engine to confirm the PCV, they’ll be loads cheaper than MB! I also need to find a good Indy in West Yorkshire who know the OM642 engine really well. Hopefully someone in the ‘know’ can recommend someone?


07 Viano 3.0

 

[Bellow]

It used to be that turbos for petrols had better sealing than those for diesels as petrols could generate strong vacuum on the over-run that diesels wont. Whether that is still the case for petrols now FBW (fly-by-wire) is the norm (giving the theoretical option of leaving the butterfly open while cutting fuel on the over-run) I do not know. Or any other strategy deployed by FBW (eg, increasing butterfly open gradually with rpm when the pedal is floored) - though I'd like to.
Diesels that employ throttling as part of EGR admission may be more demanding on turbo sealing - though again, I don't concretely know.

Back to the OP's issue. Should we/he be concerned for the potential of 'runaway' given that oil is somehow finding its way to the cylinders? Or does the grey colour imply it's a fuelling issue? Oil invariably burns to a blue hued smoke. On a petrol (under Lambda mixture control) though, significant amounts (2T levels) of oil can be burned and no smoke show.

 

[ToonTiger]

Hmm, I’m very surprised that you don’t have a PCV valve! I’m no expert, I’m sure someone on the forum may know more about the engine than I do....
Do you have a small (maybe about an inch in diameter) pipe connecting into the intake pipe that is in between your turbo and air box? If you do, that’s likely to lead to you PCV if it’s got an oily residue in it.

Other than than the PCV another explanation could be the turbo oil seals. Again, I’m not an expert but my understanding is that at idle your exhaust gas temperatures (EGT’s) are a lot lower and if you have oil leaking into the exhaust from the turbo it won’t burn off as much as it does when the engine is under load. Once you load the engine the EGT’s go up massively and start to burn the oil off. Once it’s burned away the smoke gets significantly less and won’t really be visible until the EGT’s drop again. (I think this is what’s wrong with my Audi A2 Tdi but that’s another story). I think the only way to check for this is to either monitor oil consumption or remove the exhaust at the turbo after a long idle and check for oil.

Maybe someone could confirm my thought above? I hope it’s not that though as that’s more hassle than a PCV valve!


07 Viano 3.0

Hi thanks for the detailed reply, I'm determined to sort this problem out.
Luckily for me it passed the mot last week, fortunately it wasn't left idling!
I will pass your comments onto the local garage I use.
Also thinking is it worth getting a Star diagnostics check.
will let you know how I get on
Thanks

 

[Steeelyglint]

Hi how did you get on? I have a Viano with a 2.2 diesel that is chucking out embarrassing amounts of blue smoke after idling. Did you find a PCV and did it cure it?

 

[Steeelyglint]

Could the Op update on the outcome please? My 2.2 Viano 2008 has the same problem and the garage recommended changing the turbo. I've paid for it to be changed (£900)but I don't think it's fixed! They claim it's still burning oil off from the exhaust but I'm very sceptical.

 

[Toodog]

Could the Op update on the outcome please? My 2.2 Viano 2008 has the same problem and the garage recommended changing the turbo. I've paid for it to be changed (£900)but I don't think it's fixed! They claim it's still burning oil off from the exhaust but I'm very sceptical.

Hi
I had the same smoke issue with my ‘06 and was worried my turbo was going.
In the end I had the injectors refurbished, new glow plugs installed and the engine management software updated which added some extra bhp and solved the smoke issue.
Turbo was ok.