Diesel smoke issue

[scorpio stu]

Hi
Ongoing issues
W211 320cdi V6
Has been on star
Came up with back pressure sensor & oxygen sensor
Both have been replaced. No codes showing at all.
Smoke seems to build up on idle. Light grey coloured. On kickdown there is some as well but the car has done 178000 miles so not overly concerned.
It was bucking on hard acceleration but that seems to have subsided a little. I've put terraclean cat cleaner in and it did improve but sat in traffic at Silverstone last weekend there was a ton of smoke.
Going to give it a blast up the motorway now as the old back pressure sensor was caked in soot.
Any other ideas without codes. Thanks. Mot in October so need progress by then !

 

[scorpio stu]

Forgot to add.
Actuator moving believed as it should, turbo replaced July 2020 by previous owner.
Maf sensors replaced when the Turbo was done.

 

[scorpio stu]

Just found out from the previous owner that the actuator was replaced at the same time as the turbo last year

 

[Benzowner]

178000 miles maybe piston rings or bores, that would usually give a bluish tinge to the smoke though.

 

[cbxpete]

178000 miles maybe piston rings or bores, that would usually give a bluish tinge to the smoke though.

More likely to be injectors leaking.

Peter.

 

[scorpio stu]

More likely to be injectors leaking.

Peter.

That's my next thing to do. The smoke gets gradually worse when the car is idling. Does that sound like a leaky injector ?

 

[cbxpete]

That's my next thing to do. The smoke gets gradually worse when the car is idling. Does that sound like a leaky injector ?

More than likely, I have a Jeep with the OM642 engine, same symptoms as yours. Was in heavy traffic in Plymouth earlier, tend to put in neutral when at a standstill and increase revs to about 1000 rpm to avoid smoke screen for those behind, seems to ease the smoke.
Otherwise drive perfectly.

 

[scorpio stu]

More than likely, I have a Jeep with the OM642 engine, same symptoms as yours. Was in heavy traffic in Plymouth earlier, tend to put in neutral when at a standstill and increase revs to about 1000 rpm to avoid smoke screen for those behind, seems to ease the smoke.
Otherwise drive perfectly.

Have you had a leak test to confirm what is definitely wrong and pinpoint which injector it is ?

 

[mercmancdi]

If it’s blue smoke , would it most likely be oil burning / perhaps leaking valve seals / worn piston rings on a high mileage car.
need to deter if it’s diesel or oil burn off before doing anything.

 

[scorpio stu]

If it’s blue smoke , would it most likely be oil burning / perhaps leaking valve seals / worn piston rings on a high mileage car.
need to deter if it’s diesel or oil burn off before doing anything.

To me the smoke looked grey

 

[cbxpete]

To me the smoke looked grey

Yes mines light grey, smells different to oil smoke, bit of a tang to it. I'm looking to replace the Jeep later this year so not spending any more on it. Just replaced the glow plugs, glow plug module and turbo actuator to keep using it for the time being as my every day driver. Use the SL55 when I need a fix, traffic permitting.

 

[scorpio stu]

Yes mines light grey, smells different to oil smoke, bit of a tang to it. I'm looking to replace the Jeep later this year so not spending any more on it. Just replaced the glow plugs, glow plug module and turbo actuator to keep using it for the time being as my every day driver. Use the SL55 when I need a fix, traffic permitting.

Have you confirmed yours is a leaky injector?

 

[mercmancdi]

Sorry my fault been reading too many threads I thought I read blue. White is likely to be unburnt fuel , bluesy grey likely oil ,
too pure a white could be turbo , but I think you stated turbo was sorted and cars running ok. . Don’t want to sound silly but make sure you have a nice clean air filter.

 

[cbxpete]

Have you confirmed yours is a leaky injector?

No, haven't bothered, it seems to be the consensus of opinion by several commercial fitters over the last couple of years. I have changed the PCV valve, changed the turbo seals and as I live in a very rural area I can live with it.

 

[scorpio stu]

No, haven't bothered, it seems to be the consensus of opinion by several commercial fitters over the last couple of years. I have changed the PCV valve, changed the turbo seals and as I live in a very rural area I can live with it.

Fair enough. Just trying to find out the cost to do it.

 

[cbxpete]

Fair enough. Just trying to find out the cost to do it.

I'm sure somebody more knowledgeable than I will be along soon with approximate costs. I didn't fancy doing it myself, the local garage said it would be a few hours work but declined to estimate the cost.

 

[scorpio stu]

Can anyone give me a price please

 

[scorpio stu]

Does anyone know how much I should be paying for injector leak test ?

 

[Tuercas viejas]

Does anyone know how much I should be paying for injector leak test ?

Well on this side its $50 per injector at a Bosch dealer, . which spits out a 5 sector test paper on their computer controlled tester.
Why not give these folk a jingle in Darwen Lancs

Diesel Fuel Injection Components, Parts and Spares - Darwen Diesels Ltd

Diesel Fuel Injection Components, Parts and Spares

www.darwendiesels.com

I still use them for odd ball stuff I can't get here Stateside .
All the best
Tuercas viejas

 

[Jobsworth]

From what you describe it sounds like dripping injectors to me. Automarine Diesel in Portslade do my testing, but I buy replacements from mercedes. Their service-exchange units are £218+vat each last time I bought some, but they are new units when you open the box. Last one I did, five were dripping, one was good. After discussion with the owner we replaced all six. No brainer really.