[modobrew]

So on my normal morning commute today I started to notice diesel exhaust smell inside the cabin about 45 miles into my commute (95% hwy). I looked down at my torque app and the EGR was reading 0% and the EGT was running in the normal range, and remained at 0%??? Typically I see EGR around 94% when the EGT is in the 500-550F range. So this seems rather odd to me. This lasted probably 7-10 minutes, maybe longer, at which point the EGR went up to about 16% and then my EGT started to climb. Shortly after, the car did a regen (EGR 0%, EGT 1170F or so) and the exhaust smell went away??? This is the first time I have noticed this (exhaust smell in cabin, 0% EGR, EGT @ 550F).. What gives?

A little background...
Temperature outside was 7F, first time I've driven the D in temps this low. Would that affect it at all? (Car is garaged ~45F in the garage this morning.) It last did a regen cycle about 450-480 miles ago, which I believe is in the proper range. I'm baffled by this and hope that it's not the charge pipe...

Any help would be greatly appreciated guys.

Lee

[2deerwhistlers]

Originally Posted by modobrew

So on my normal morning commute today I started to notice diesel exhaust smell inside the cabin about 45 miles into my commute (95% hwy). I looked down at my torque app and the EGR was reading 0% and the EGT was running in the normal range, and remained at 0%??? Typically I see EGR around 94% when the EGT is in the 500-550F range. So this seems rather odd to me. This lasted probably 7-10 minutes, maybe longer, at which point the EGR went up to about 16% and then my EGT started to climb. Shortly after, the car did a regen (EGR 0%, EGT 1170F or so) and the exhaust smell went away??? This is the first time I have noticed this (exhaust smell in cabin, 0% EGR, EGT @ 550F).. What gives?

A little background...
Temperature outside was 7F, first time I've driven the D in temps this low. Would that affect it at all? (Car is garaged ~45F in the garage this morning.) It last did a regen cycle about 450-480 miles ago, which I believe is in the proper range. I'm baffled by this and hope that it's not the charge pipe...

Any help would be greatly appreciated guys.

Lee

Maybe the 'bellows' from the exhaust manifold to egr cooler has cracked? I would look for soot in this region with the engine cover off

[Mark M]

Do you have a catch can? If so, did you use heater hose for the plumbing? I found heater hose degrades over time when used with oil vapors and becomes porous. My car has developed an oil smell as a result of this with oil residue on the outside of the hoses. I'm trying to source 3/4" CPE or Nitrile hose to redo my catch can correctly.

[modobrew]

Originally Posted by 2deerwhistlers

Maybe the 'bellows' from the exhaust manifold to egr cooler has cracked? I would look for soot in this region with the engine cover off

I'll take a look this evening with the engine cover off. EGR cooler is over on the passenger side of the engine bay, correct? I think I remember seeing it when I was looking to install the EGR black plates. Haven't installed those yet, but I think I remember the cooler being over in that region.

Originally Posted by Mark M

Do you have a catch can? If so, did you use heater hose for the plumbing? I found heater hose degrades over time when used with oil vapors and becomes porous. My car has developed an oil smell as a result of this with oil residue on the outside of the hoses. I'm trying to source 3/4" CPE or Nitrile hose to redo my catch can correctly.

No oil catch can installed.

[TDIwyse]

Originally Posted by modobrew

... I looked down at my torque app and the EGR was reading 0% and the EGT was running in the normal range, and remained at 0%??? Typically I see EGR around 94% when the EGT is in the 500-550F range. So this seems rather odd to me. ...

http://www.bimmerfest.com/forums/sho...6&postcount=25

In extreme cold weather the vehicle will turn EGR off. At least that's what I've measured over the years...

[BB_cuda]

Originally Posted by 2deerwhistlers

Maybe the 'bellows' from the exhaust manifold to egr cooler has cracked? I would look for soot in this region with the engine cover off

Seems i recall threads where the outlet region of the cooler showed some cracking. The salvage cooler that i got from dealer mechanic had soot on one of those 90° pieces along outlet tract leading to EGR housing mating flange. Those brazes crack. It had been replaced under warranty for leaking (gas not water).

Seems someone else spoke of a cracked hose coming off of DPF going to differential pressure sensor. There are many potential sources of smell. I would have to think harder to what would make smell go away after regen completed though.

[2deerwhistlers]

Well during regen you're putting extra fuel out the exhaust.. That's a good start

[Yozh]

Here are the sources of exhaust smell that I could think of:
-EGR cooler and all the way to the EGR itself.
-DPF connection to the turbo flange
-differential pressure sensor and hoses
-exhaust pressure sensor and its connection
- the other ones you do not really want to even think about, like your turbos or the manifold.

One item to consider here is the relation of exhaust back pressure to the smell and the fact that the smell went away after the regen. A few of the above mentioned may exhibit leaking with increased exhaust back pressure but not otherwise. I would start at the differential pressure hoses and look at the whole EGR cooler and all the way to EGR itself. If you had smell at stationary then could be lots of things. If you were in motion then most likely differential pressure hoses.