Intermittent smoke coming from engine bay (OM642 W212)

[TeddyRuxpin]

Hi,

About a month ago I was in London traffic and noticed some smoke/steam coming from the passenger side of the engine bay (RHD car) - it would come out of the corner, near the wiper, where the battery is in the engine bay. I wasn't sure if I was imagining it or if it was the exhaust fumes of the car in front! It was not constant, extremely intermittent (I haven't seen it in a month) so I'd catch a flash of it then look, and it might be gone, or carry on for a couple of seconds.

I got home and looked and the engine and the only thing I found was some vapour and a leak from the PCV, which is on the other side of the engine. I have now replaced that, no more leak from there - although it was a different kind of 'smoke'/vapour coming from there, much thinner.

However yesterday, in traffic, I noticed a bit of smoke/steam/vapour coming from the same spot (passenger side), much to my annoyance.

Does anyone have any idea on what things to check for? I can't see anything really obvious in the engine bay, but I'm still new to this engine and I'm not sure where everything is located

The only thing in the actual engine bay over that side is the EGR valve - is that something that could do this? I can't see anything near the battery (cover still on).

Cheers for any suggestions!

Ed

 

[Larkone]

Oil cooler seals starting to give out possibly

 

[TeddyRuxpin]

Hi,

Sorry, I should have mentioned - they were done by MB 2.5 years ago (about 25K miles ago) and the oil cooler itself, the seals, and a bunch of other stuff were changed, so it’s unlikely to be that.

I also forgot to say that I changed the main turbo seal again recently, along with the new seal on the breather pipe from the PCV, as well as the two oval shaped seals on the air intakes.

Cheers,

Ed

 

[Larkone]

Put some cardboard under the engine to see if there are any leaks/drips as that will help determine what is causing the smoke - moisture or oil

 

[Petrol Pete]

If it is oil you will smell it in the cabin, vapor/steam ? not so much, or not at all.

 

[rudolfdiesel]

Have you managed to fix it? I have the same problem it seems

 

[TeddyRuxpin]

Yes, the problem was a fuel line leak. It was happening all the time, but was only 'obvious' during DPF regens, as the engine and exhaust heats up so much that the diesel starts to smoke. Diesel doesn't usually combust at these temps but it's important to be careful and check ASAP if you have a diesel leak.

I was lucky in that the mechanic I took it to just had to re-righten a fuel line on one side of the engine (at the top of the V) and didn't require any new parts.