CLS 350 CDI -Puff of Blue Smoke on Startup After Standing

[Mattboocock]

I've had 3 cars with DPF. All 3 have had minor sooting on the exhaust pipe. The only other one I looked at closely was a mates 2014 Scirocco diesel (don't ask), and we had to get the Autosol on the exhaust tips to give them a good clean as they had never been cleaned.

So I would say some minor sooting on DPF exhausts is normal in my experience. But nothing like the sooting that my dad's 2004 Volvo D5 gets.

Yes the D5’s did smoke a lot but great engines in the day!
I’ve cleaned my tail pipes so let’s see if they soot up again..... although the morning smoke is blue..

 

[Mattboocock]

Update...

car is now constantly going into limp mode when engine cold and accelerate lightly.. happens at 13-1500 rpm but NO EML comes on?? I switch the engine off pull the key out put it back in start up and then it’s fine!

merc dealer says they need the EML so they can read the fault code??

warranty runs out in 4 weeks so need it sorting ASAP but they’ve basically said “wait til EML comes on and then bring it in”

 

[MrGreedy]

Sounds a lot like they've said 'wait until the warranty runs out, then bring it in'.

Best of luck, keep pushing them and keep us updated.

 

[Mattboocock]

Sounds a lot like they've said 'wait until the warranty runs out, then bring it in'.

Best of luck, keep pushing them and keep us updated.

Yeah shall do. As they previously replaced the ECU under warranty, I got the impression they didn’t want to do any more warranty work on it… As they said without the engine management light coming on that have to use a different system to “dig down “deeper into the brains of the engine?!

I have an independent garage that I will trust to take it to but of course they’ll charge me £80 to do a diagnostics check.

 

[MercedesDriver]

Blue smoke is usually related to burned engine oil, so if you're having blue smoke only on start-up it might be that valve seals are bad and the oil is finding it's way to the combustion chamber over night and then get burned out with the first ignition. I don't think that blue smoke has anything to do with DPF.

 

[Mattboocock]

Blue smoke is usually related to burned engine oil, so if you're having blue smoke only on start-up it might be that valve seals are bad and the oil is finding it's way to the combustion chamber over night and then get burned out with the first ignition. I don't think that blue smoke has anything to do with DPF.

Thanks for that. Yes it’s just when engine stone cold. Nothing when warm and hard acceleration

 

[E55BOF]

If you get an EML, as far as I know any associated fault code will be stored until actually cleared with a scanner. It can subsequently be read even if the EML has gone out. TBF, though, it is always better to have the EML still on when reading the codes, just in case it's a transient glitch that does not generate a fault code.

On a start from stone cold, you may get a puff of white vapour; this can only be unburnt atomised fuel. Leaving it a couple of seconds after the glowplug light goes out before actually turning the key to engage the starter may help. See this thread for more: CLS 350 2013 Cold/first start problem - part 2 | Engine

I now own that car, and it still does it; I think it's more a characteristic than a problem. It is only white vapour, though, not blue-black.

There's a recent thread somewhere, but I can't find it, singing the praises of Archoil 6200 and 6400 for diesel engines. Damned if I can find it, though.

 

[Bellow]

There's a recent thread somewhere, but I can't find it, singing the praises of Archoil 6200 and 6400 for diesel engines. Damned if I can find it, though.

V Power Petrol Prices | General Discussion

£1.37,99 Tesco momentum Asda normal unleaded £1,20.99 lincoln

forums.mbclub.co.uk

 

[Petrol Pete]

Thanks for that. Yes it’s just when engine stone cold. Nothing when warm and hard acceleration

5 seconds of visible smoke is a MOT fail on a 'Major' I would personally not bother polishing the exhaust tips . I would be spending every day of the last 4 weeks of the warranty getting the car in their workshop by hook or by crook.

 

[Mattboocock]

If you get an EML, as far as I know any associated fault code will be stored until actually cleared with a scanner. It can subsequently be read even if the EML has gone out. TBF, though, it is always better to have the EML still on when reading the codes, just in case it's a transient glitch that does not generate a fault code.

On a start from stone cold, you may get a puff of white vapour; this can only be unburnt atomised fuel. Leaving it a couple of seconds after the glowplug light goes out before actually turning the key to engage the starter may help. See this thread for more: CLS 350 2013 Cold/first start problem - part 2 | Engine

I now own that car, and it still does it; I think it's more a characteristic than a problem. It is only white vapour, though, not blue-black.

There's a recent thread somewhere, but I can't find it, singing the praises of Archoil 6200 and 6400 for diesel engines. Damned if I can find it, though.

Thanks for that. I’ve watched the YouTube clip you suggested and mine is defo blue on cold start up but only for a second or two... I’ll try the second delay on ignition after glow lights out and see what happens...

 

[Mattboocock]

5 seconds of visible smoke is a MOT fail on a 'Major' I would personally not bother polishing the exhaust tips . I would be spending every day of the last 4 weeks of the warranty getting the car in their workshop by hook or by crook.

Your right.... this needs sorting because they’ll identify the issue immediately after it runs out no doubt!!

 

[Mattboocock]

V Power Petrol Prices | General Discussion

£1.37,99 Tesco momentum Asda normal unleaded £1,20.99 lincoln

forums.mbclub.co.uk

Interesting read!!

 

[E55BOF]

V Power Petrol Prices | General Discussion

£1.37,99 Tesco momentum Asda normal unleaded £1,20.99 lincoln

forums.mbclub.co.uk

Thanks for that. I must have skim-read that thread three times, and managed to miss that (skipped the page?) every time; must be getting old...