BMW M5 Forum and M6 Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
180 Posts
Discussion Starter #1
I'm noticing a pretty stinky mildew smell whenever we get bad rain. I've ran my hand across every surface of carpet in the car and I can't find any wet spots. Took a good look at the pillars and headliner and don't see anything wet. Also checked the trunk.

I don't think it's A/C related because I can smell it as I open the door and get in the car.

Any ideas?
 

·
Registered
Joined
·
180 Posts
Discussion Starter #2
I should note I did notice moistness on my rear door sills. Is this an indicator of vapor barrier failure?
 
  • Like
Reactions: omgroffles

·
Registered
Joined
·
43 Posts
Probably. The door sills should be completely dry. Check the drain holes on the bottom of the doors, too. If plugged, water can accumulate inside the doors, even if it does not reach the bottom of the not-completely-sealing vapor barrier and spill out on the carpet, and may cause mildewy/fetid conditions. Ask me how I know.
 
  • Like
Reactions: omgroffles

·
Registered
Joined
·
180 Posts
Discussion Starter #4
Probably. The door sills should be completely dry. Check the drain holes on the bottom of the doors, too. If plugged, water can accumulate inside the doors, even if it does not reach the bottom of the not-completely-sealing vapor barrier and spill out on the carpet, and may cause mildewy/fetid conditions. Ask me how I know.
Thanks, I'll check this out tomorrow morning. Really wanna get this fixed... the smell is embarrassing. I guess it's good that I'm not getting half an inch of water in my carpets like other folks but I really gotta track down the source of the smell.
 

·
Registered
Joined
·
43 Posts
Thanks, I'll check this out tomorrow morning. Really wanna get this fixed... the smell is embarrassing. I guess it's good that I'm not getting half an inch of water in my carpets like other folks but I really gotta track down the source of the smell.
In my 03/540i the smell of mildew was terrible with all vapor barriers replaced, drain holes cleaned and all carpets + padding bone dry. I figured it must be the A/C condenser(?) under the dash, even though I have not used the A/C once in the 3 years I owned the car (like to drive with the sunroof open :7:). However, the PO probably did. The smell was so strong that everybody riding in the car was commenting on it. Embarrassing to the nth degree. Went to the stealer and had them perform a cleaning service. They were very cognizant of the problem and said they do this quite often. I assume that they sprayed their factory-supplied mildew killer solution in the cabin air intake with the heat/A-C blower on with the micro filters removed. IIRC, paid about $60.00 (1/4 hour labor + ca. $25.00 for the solution). IIRC, I waited some time to pick up my car in order to let the solution completely evaporate. Smell was gone and the car smelled fresh. I did not want to do this myself because I believe that the solution is probably very strong (more than likely contains some fungicidal agent [mildew=fungus]), and I figured that you must have experience to spray just the right amount. Also, there are DIYs (Bfest, Bforums) where you drill a hole on the side of the foot well to access the condenser inside in the middle and pretty much blindly spray some anti-mildew solution directly on the condenser and its tray with a wand. Paying the $60, in my opinion, was well worth it. The stealer also said that more than likely I'll have to repeat the process in a year or two. No problem.
 

·
Registered
Joined
·
43 Posts
Also, I should add that you should check the underside of the carpet/padding for mildew that may have developed from previous wet episodes. Furthermore, shampooing the carpet wouldn't hurt either.
 

·
Registered
Joined
·
143 Posts
Wow super timely thread. I just discovered my rear mats and carpet were soaking wet this morning after our extra rain in California. I couldn't figure out why the rear was wet and the front was completely dry.

EDIT: timely because I had no idea this was a common issue. I was beyond confused thinking I must have left my windows cracked or something else. Because of this thread I was able to search vapor barriers and now I have a much better idea on how to attack this problem. Thanks!
 

·
Registered
Joined
·
2,917 Posts
Wow super timely thread. I just discovered my rear mats and carpet were soaking wet this morning after our extra rain in California. I couldn't figure out why the rear was wet and the front was completely dry.

EDIT: timely because I had no idea this was a common issue. I was beyond confused thinking I must have left my windows cracked or something else. Because of this thread I was able to search vapor barriers and now I have a much better idea on how to attack this problem. Thanks!
Also as a heads up, if the problem still persists after replacing the vapor barrier, you may have to look into your sunroof drains.
 
  • Like
Reactions: omgroffles

·
Registered
Joined
·
180 Posts
Discussion Starter #9
The weird thing for me is I can't find any wetness on the carpets. I suppose its possible theres water pooling in my doors but that means I'd have to pull apart all 4 door panels to confirm that theory.

Is it possible the mildew is in the A/C system and the smell just creeps into the cabin? I know with most people who have that issue the smell doesn't appear until the A/C is used... but this is just a persistent stink that is there 24/7 until it dries up.
 

·
Registered
Joined
·
301 Posts
I had this problem before, in a different BMW. It ended up being the drainage tubes in the windshield pillars getting clogged with dirt and debris. I would blow some air through the sunroof drainage holes and see if that helps.
 

·
Registered
Joined
·
180 Posts
Discussion Starter #12
I had this problem before, in a different BMW. It ended up being the drainage tubes in the windshield pillars getting clogged with dirt and debris. I would blow some air through the sunroof drainage holes and see if that helps.
Thanks! I just gave this a try but it started to rain down pretty heavy the second I opened my sunroof and started blowing air through it. I'm gonna give it another try tomorrow if I am blessed with some dry moments after work.

Along with the smell, I do get fogged rear + front windshields in the morning. On my way home from work this isn't a problem but I did notice my sunroof glass was fogged up today. Possibly an indicator of moisture in the sunroof drains?
 

·
Registered
Joined
·
180 Posts
Discussion Starter #13
Okay, bringing this one back from the dead. We had our first rain in a few weeks and the smell has returned :(

I'm not sure what else to look for aside from pulling my carpets and checking the foam underneath. The smell is rank, and I still cannot find any moisture or wetness inside the interior or trunk at all.
 

·
Registered
Joined
·
991 Posts
Okay, bringing this one back from the dead. We had our first rain in a few weeks and the smell has returned :(

I'm not sure what else to look for aside from pulling my carpets and checking the foam underneath. The smell is rank, and I still cannot find any moisture or wetness inside the interior or trunk at all.
You need to pull your carpets and check the foam backing. Lots of times the water doesn't leak directly on top of the carpets, but on to the floor beneath them. The foam then absorbs it like a sponge leaving the top of your carpets dry.
 

·
Registered
Joined
·
180 Posts
Discussion Starter #15
You need to pull your carpets and check the foam backing. Lots of times the water doesn't leak directly on top of the carpets, but on to the floor beneath them. The foam then absorbs it like a sponge leaving the top of your carpets dry.
This'll be my next move. Thanks!
 

·
Registered
Joined
·
369 Posts
I thought I was the only one who noticed a strange smell in my car. Thanks for the tips, hopefully I can stop it before it gets really awful.
 

·
Registered
Joined
·
1 Posts
Okay, bringing this one back from the dead. We had our first rain in a few weeks and the smell has returned :(

I'm not sure what else to look for aside from pulling my carpets and checking the foam underneath. The smell is rank, and I still cannot find any moisture or wetness inside the interior or trunk at all.
I have this in my E39 also and have discovered that the smell was coming from inside the doors, its like mold or something is growing in there. I found it when I took the door trim off and had a sniff in the gap for the window STINKS. Cant seem to pin point it within the door though.
 
1 - 18 of 18 Posts
Top