Could this be the source of my cabin smell? (Residue under EGR valve)

TeddyRuxpin

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Hi,

I have some pretty mild cabin smell from my OM642 engine. Most people that get into the car don't notice it, but I can (faintly). You can also smell it when you walk in front of the car/stick your head into the engine bay. Unlike another member on here, you can be going very slowly and the smell will waft in, so my hunch is more that the engine is simply hot and heating up some kind of leak or old residue.

The engine has had several leaks in the past, such as the coil cooler seals and a fuel/diesel line leak (close to the area where this residue is), which obviously leaves residue on the engine, which when hot, may stink a bit. So it could just be that?

But, I have been poking around and found this residue just underneath the EGR valve, to the side of the turbo (see pic). I've had the EGR off in the past a couple of times to clean it. I was wondering what the cause could be - my memory of this pipe is that it's only air that is released into that pipe, so it wouldn't cause this kind of leak. I did wonder if the pipe isn't on properly, though, perhaps that clip is only 'one use'.

I've actually cleaned off some of the residue from the large silver pipe and the only bit is left is the stuff that isn't easily accessible with a cloth (without removing EGR again). I'll try to clean more tomorrow then I'll be able to see if it gets dirty again.

It does not look like the green turbo seal is leaking (as that would spray oil). I can't see any other leaks, the car is running very well and no errors or CEL. FWIW the car had a new cabin filter about 10 months ago.

Anyone know if this clip/hose could cause this 'leak', or what the source of that oily residue in the area under the EGR valve could be?

Cheers,

Ed
 

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Given how many I’ve had to have changed over the years, I wouldn’t discount a leaking injector - there seems to be just a whiff of diesel in the cabin and the outside.
 
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TeddyRuxpin

TeddyRuxpin

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Ah, crap. I did used to have a leaking fuel line, but this was fixed with 1/2 labour and the mechanic simply tightened up the lines... I can't see any fuel leaking, certainly nothing like in this video... I'm currently watching:

 
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TeddyRuxpin

TeddyRuxpin

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FWIW I realise that hose on the EGR is actually a coolant hose (not just an air hose), so it could well be the source of the 'leak'/residue... could be nothing to do with the smell, though.
 

Larkone

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I would go with it being your previous leak. If you can clean the residue that would help eliminate that. When mine broke a fuel line clip and sprayed diesel all over the front of the engine and undertray I ended up with a new undertray because I couldn't get rid of the smell - it had soaked into the foam. New undertray fixed that.
 
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TeddyRuxpin

TeddyRuxpin

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Thanks!

But wait, there's foam on the undertray?! I thought they were just plastic? I just gave it a google and it just looks like plastic to me - what exactly did you replace?

When the mechanic fixed the link he said he 'did his best' to clean the residue, but as it's diesel, it's tricky as it's so sticky and... gross in general.
 

W1ghty

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Thanks!

But wait, there's foam on the undertray?! I thought they were just plastic? I just gave it a google and it just looks like plastic to me - what exactly did you replace?

When the mechanic fixed the link he said he 'did his best' to clean the residue, but as it's diesel, it's tricky as it's so sticky and... gross in general.
The main undertray on my E320cdi has a foam padding that can soak up stuff as Larkone says
 

Larkone

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The main undertray on my E320cdi has a foam padding that can soak up stuff as Larkone says
It certainly has
1601297825574.png

Those little squares are raised hollow foam so the diesel gets inside. Impossible to get out without destroying it.
 
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TeddyRuxpin

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Interesting, thank you! It looks very different to the pics of the undergrad on my W212 E350, can anyone who has a W212 chime in?

Will try to find out how much that costs for my E350!
 

W1ghty

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Interesting, thank you! It looks very different to the pics of the undergrad on my W212 E350, can anyone who has a W212 chime in?

Will try to find out how much that costs for my E350!
Look down behind the radiator , can you not see the under tray ?
 
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TeddyRuxpin

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My wheel ramps arrived today, so should be able to get underneath within the week... although... rain everyday....

From peering down through the radiator/fan, it looks like there's a load of old crap in there, but no obvious signs of a leak leak.
 

W1ghty

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My wheel ramps arrived today, so should be able to get underneath within the week... although... rain everyday....

From peering down through the radiator/fan, it looks like there's a load of old crap in there, but no obvious signs of a leak leak.
Everyone should be taking the very front undertray off every year and getting all the leaf muck out that coats the bottom of the rad and rad pipes to stop rot
 

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