F15 X5 35d - exhaust smell in interior

[Amsterdave]

I bought a 2015 X5 35d M-Sport with about 55,000kms (34,000 mi) on it earlier this year. My first ever diesel vehicle. Added a few years of warranty extension through the dealer and hope to be good for a while!

Lately I've been noticing a slight smell of diesel exhaust in the interior. When I turn the AC to circulate only (M-light on the AC controls) it goes away. If I set it on A or no light (exterior air) it comes back.

I don't think this is normal and am worried it is unhealthy for me or my young children. I've found some threads online about exhaust leaks from the EGR but those were all for older models. Is this an issue with the F15 as well? Any ideas what could be going on here?

[Mr.47]

I too have this, both my E70 35d and F15 X5 35d now 77k miles but only when its cold outside <40*F or <4*C and only last for about 30-60 seconds. Since my diagnostic tool didn't show any hidden error codes related to emission systems, and unlike my E70 35d, didn't find any soot build up around the emissions system, I chalk up as been normal.

Looking at the emissions systems (EGR coolers and EGR valves) There's a few metal hoses interconnecting to each other, and some has metal gaskets on them some connect directly by v-band clamps. I'm guessing that since its cold the metal hoses and gaskets has contracted not creating a proper seal thus small amounts of fumes leaks out until the exhaust heats up expand the metal gasket and metal hose to seal it off.

[smyles]

On e70 it was almost a cracked EGR cooler (replaced twice on mine). Lesser possibilities - loose or cracked exhaust manifold.
I'd check for the same.

[Amsterdave]

Thanks, I will get it checked on the next service. It does seem intermittent and related to cold weather (I didn't notice it this summer, but then again the issue may just not have existed yet at that time). The intermittent nature of the issue could also be related to the climate control alternating between fresh and recycled air. I notice it most in stop/go traffic (70% of my driving unfortunately), not on the highway..

[Amsterdave]

Just a quick update... I took the car in to have this issue looked into today. Turned out there was something loose in the engine bay, causing the exhaust fumes reaching the interior. I am a little concerned that a loose hose did not trigger a CEL/MIL or other warning, but other than that it seems to be resolved now.

Attached is the work order and mechanic commentary...

[BMW_Diesel_Owner]

Could someone please provide instruction on how I can locate and rectify the issue? Thank you very much!

[scootr]

Originally Posted by BMW_Diesel_Owner

Could someone please provide instruction on how I can locate and rectify the issue? Thank you very much!

Diddo here. New for 2018 X5 35d with diesel smell inside - Guess I could remove the engine cover and hunt around but it sure would be sweet to know what I'm looking for and where ~ Cheers

[BMW_Diesel_Owner]

How can we locate the valve cover breather tube? Thanks in advance!