I just purchased my new 2009 Altima Coupe 2.5S about a month ago. When I turn the air conditioning on, it's fine. However, sometimes when the air conditioning is off and just the vent is running (this is with and without the circulation on), my car blows out this humid, fungus odor. I first took it back to the dealership, and they said nothing was wrong. I complained to corporate and ended up taking it back for a second time. They sprayed a deoderizor threw my vents. It worked for about a week, then the smell came back. I'm scheduled to take it back in for a third time this weekend. DOES ANYONE HAVE ANY IDEAS ON WHAT IS THE PROBLEM AND/OR HOW TO FIX IT? Anyone have this problem with their new altima? Obvisously the service center doesn't have any clue.

I have the same exact smell so i know what your talking about i just never thought anything about it so i never brought it in

when you run your ac for awhile and shut off ur vehicle without "drying the vents" out by switching from cold ac to vent only, and letting it blow for a few seconds..you get that ugly mildew smell.

But this can happen even though I "dry the vents" by turning the air con off and letting the regular air run about 4 minutes before I get home. When I'm ready to go to work the next morning, the smell comes out again. When I take my car out for lunch, it's there again even though I haven't ran my air con the whole day. It's a variable, but frequent problem. Is there any suggestions as to what I or the service center can do? Perhaps mildew did build up in the system somewhere? This is the only thing that's keeping my from being completely satisfied with my altima.

i had this too for a while, they changed my in cabin filter and it got rid of the smell

THANK YOU! I'll make sure they do that when I take it in for the 3rd time. Make sense, is it hard to do? Do you know if I can do it myself and save me the trip?

its pretty easy to diy- theres a diy writeup about it- saves urself a bit of time/money too

Lol i thought this is something common when you just turn the fan on. i've always experienced this in all the cars i've driven

yeah it's a diy job, just buy the filter, then you can remove your glove box and squeeze it out, it's aparently a really tight fit. i'm not sure where the diy thread is, but it's somewhere

http://www.nicoclub.com/subpages/nissan-tech.shtml

check for the coupe section at the bottom, in "how-to change in cabin air filter" good luck!

Guys, Foul smell can be a very serious issue. I have 2008 Altima. I started noticing a real bad smell in my car during driving. I also noticed that my a/c used to turn off automatically and start blowing hot air. One day I was driving on a highway and my engine stopped of its own as if it was getting heavily overloaded. I was able to restart the engine but "Service Engine Soon" warning came on.

Dealership diagnosed that the THERMOSTAT which is mounted in the engine was bad and it was not letting the coolant flow and cool the engine. Bad smell was the smell of coolant being burned when engine was getting overheated. Whenever the engine temperature used to rise, the controller used to turn off a/c to remove load from the engine. And when the engine temperature was touching its high limits, it went into the safe mode and stopped to prevent any damage to the engine.

After they replaced the thermostat assembly, I got rid of foul smell and also my a/c does functions properly.

This seems to be an old thread and since it was revived, I figure I would add my experience too. I would sometimes get this weird smell. It's not a foul smell per say. It's more like a mouldy/smelly socks smell. Ok... that could be foul too but not a burning type smell. This would happen if I turn on the A/C for a while to cool things down. I would then turn off A/C because it was cool enough. Shortly after, with vents only, this smell would appear. Like smelly feet. This is not consistent. Once in a while only. This is a 2009 Altima and experienced this almost 6 month months after the car was brand spankin new. My previous car, a 2008 civic si had this same issue. It too was a brand new car. I'm not too concerned. If this happens when I have passengers in the car, I just remind everyone that it's not my smelly feet!

Speaking of changing cabin filter, can't find the how to stated above. I purchased a filter on ebay for about $12. I was able to get to the filter but it is a b**ch to get out. Still haven't changed it yet. The opening for the filter is waaaay smaller than the filter itself. Boggles my mind.

If you have cloth seats, make sure to not fart in them cause they soak in the seat and produces mold

i used to havea jetta and the previous owner had a dog they would take with them everywhere (including the car). Hence, whenever it rained and humidity settled in, a distinct wet dog smell would penetrate the whole car.

Mayb inquiring on the previous owner's driving habits (if your car is used) could clarify any issues.

I think this is all about perception and what we are defining as "bad smell". Both the Altima and previous Civic were brand new from dealership (less than 50kms on them) and I still experienced this odd smell from time to time after using air conditioner. I think it's quite clear that in previous posts, everyone talks about the smell coming out of the vents and not from seats or carpet.

I was just kidding bout the fart lol

I get this smell with all my cars after turning off the A/C and keeping the fan on. It's a simple fact that when the AC turns off, the humidity that had built up from the cold are hitting the vent surface, starts to flow through and you get that pungent smothering smell at times. I can't stand it for more than a few seconds so I usually turn the FAN off as well and hit the circulate button (to keep outside air from coming in the vents and continuing the smell), OR I turn the AC back on and move the temperature knob to the least cold position (right between blue and red) so it keeps the humidity in check without getting too cold.

i've heard that if you run your car with the vents all the way up at high temp for a few minutes it can "burn" off the smell

johnnir3volution wrote:I was just kidding bout the fart lol

No you weren't.... you were referring to those nasty wet ones

yeah i get that smell too, i just turn everything off
but sometimes when i just leave it on it goes away after like 5 mins

johnnir3volution wrote:If you have cloth seats, make sure to not fart in them cause they soak in the seat and produces mold

Helps to wear pants when you drive.

get car cologne
hahaaha

Bumping this thread. I have the same problem. The air coming from the fan without A/C smells like a moldy wet dog. It's definitely not the air cabin filter, since I changed it recently and it didn't do a thing for the smell. From what I've read, it might be a clogged condensation drain, which starts to can moldy and nasty. I have never noticed any condensation drip from the car, so I suspect that may be the problem.

Some have suggested trying to burn it off by leaving the heater on for a bit. I'm afraid it will just stink up the cloth interior, and may just make it worse in the long run.

I will try to find the condensation drain, and keep y'all posted with my findings. Anyone else have this issue by chance?

open all windows and sun roof, point vents out windows, set settings to "face" only, blast heat.

I wasn't planning on hot-boxing it... lol. Nasty.

I am on my third Altima and I had the same issue with 2 of them. They actually sell a spray that u spray into the vent by the passenger side hood hinge. I forget the name basically it's a a/c heater odor/mildew neutralizer it doesn't mask the Odar it kills the mildew bacterial the "wet dog smell" I'm on my iPad on a train or I'd search now but I know I bought it from amazon not to long ago.. Auto stores sell it but not commonly till summer time.. You blast the vents and spray it in it smells amazing and does really work...