# Musty Smell with Sun Roof Open



## 67BMW/2 (Apr 15, 2011)

Hello Fellow Oil Burners,

I have had my 335d for two months now, but 2600 miles on it so far and I love the torque and gas mileage. This BMW has a personality with the diesel grumble at low speeds, and the roar of a V-8 when you punch it. Fun all the way around. I am using the JBD tune at 100% which has given it even more power.

One thing I have noticed is the moment I crack my sun roof, a musty smell permeates the cockpit. It is better when I push the "recirculate air" button on the A/C. The moment I close it, it goes away. Its almost by opening the sun roof, the pressure drops and lets in some diesel odor. 

I was thinking it might be new car residue burning off engine parts etc but it still happens 2600 miles later. Has anyone else experienced this? 

Cheers All,


----------



## autoJeff (Oct 1, 2009)

I have not.


----------



## Snipe656 (Oct 22, 2009)

I don't use my sunroof much but can't say I ever have noticed strange smells when I do. But this is Houston and not like our air smells all that great anyway


----------



## János (Jun 19, 2010)

If you query the main 3-Series forum you should find something relating to sunroof drains becoming blocked (and how to fix it). My guess is that perhaps the drains have become blocked and you are smelling the result.

One thing though - mold and diesel are two different sorts of smells. Does it smell moldy/musty or does it smell oily?


----------



## Flyingman (Sep 13, 2009)

János said:


> If you query the main 3-Series forum you should find something relating to sunroof drains becoming blocked (and how to fix it). My guess is that perhaps the drains have become blocked and you are smelling the result.
> 
> One thing though - mold and diesel are two different sorts of smells. Does it smell moldy/musty or does it smell oily?


Or does it smell sort of a pungent sweet smell. That would be the regeneration.


----------



## 67BMW/2 (Apr 15, 2011)

Hi All,

I just got the D two months ago so I am getting used to the nuances. Flying man hit it, its a pungent sweet smell. But I smell it all the time when my sunroof is open. If I recirculate the air, it almost goes away. I love having my sunroof open on the rare sunny days up here in Seattle, but I think twice about it due to the smell issue. Maybe it will go away with time. As a side bar, every morning I have cobwebs all over the interior. Seems like a spider made its way into my car. I may need to fog the interior to get rid of it or them.

Cheers..


----------



## Snipe656 (Oct 22, 2009)

It should not be there all the time though at least not the regeneration smell. Or guess I should say that is not the case with mine. When mine is doing it, I can smell it with the windows up and sun roof closed but because I have the AC set on auto in regards to recirculation settings. Why BMW did not program the car to not pull outside air in when the regeneration is happening and AC is set to auto for recirculation, seems like a silly oversight. But perhaps I just have a poor sense of smell and what I think I am smelling as the regeneration is actually something else with the car.


----------



## autoJeff (Oct 1, 2009)

I don't think I smell mine during regen with windows closed and recirculate set to auto. I have smelled it a couple time after pulling in my garage during a regen event.


----------



## Snipe656 (Oct 22, 2009)

autoJeff said:


> I don't think I smell mine during regen with windows closed and recirculate set to auto. I have smelled it a couple time after pulling in my garage during a regen event.


To be honest, I am not sure I have since I had the software update done. When the update was done I ended up getting a few "features" that others on here already had in their 2010 cars.


----------

