[muhanda1]

Model 320d 2010
Car is 3 yrs old now.
Every time when I turn the heating or cooling on it sucks fumes from outside.
Doesn't matter what I select from the little push button on the dash with 2 green lights above it. I had this problem since bought the car brand new. Took the car to 2 Dealers under warranty and they said there is no problem with it. Now I had enough of it. Is there anyone experienced the same problem or similar. Could someone please give me some ideas where to start.
Thanks

[196806]

Common. You might have minor oil leak somewhere. It only happens to mine when I've got an oil leak to fix - unless you have a serious leak oil with normally burn off resulting in the fumes coming into the car unless you drive with the air recirculating.

[muhanda1]

I can smell it only when the fan is running (ie cooling or heating on) and the front vehicle is smokey. It's definitely coming from out side irrespective of whether the air is re-circulating or not.

[Scotty89]

Yes, I think what he's saying is that unless you've got a serious oil leak, the fumes are just residual oil burning up.

If it's just oil burning up, the smell should go away after it's burned up the residue, unless it's constantly leaking and feeding the fumes into the cabin.

Have you tried searching for oil leaks in the engine bay?
The cabin air filter is under the cowl at the top rear of the engine bay, so any hot oil fumes will end up going through it and coming into your cabin. Once it's in there, recirculate will only cycle it around and around.

[muhanda1]

There are no oil leaks. I have a feeling one of the vents not closing properly so it sucks outside air through the defective vent. I do not where to start?http://www.e90post.com/forums/images...es/mad0259.gif

[JinAM]

It's most likely one of the flap in the air/con box isn't working properly. Go to a better dealer, if you are still under warranty. Easy way to show them the fault is turn on full recirculate with fan on, spray fragrance around the microfilter housing and see if you can smell it inside.