[Soul_Glo]

After about 20 minutes of driving... with a/c off... and temp set to 23 degree celcius... knurled wheel set to red... there is a smell that stinks to high heaven...

Gym socks, horse shit... how else can I describe it?

Switching the a/c on for a few minutes cures it for a while but toward the end of the journey it only returns with vengence.

Any advice much appreciated.

[Alex.J]

Somebody put some turd in your pollen filter?!

Could be mould in the system, a regas and flush would be advised!

[Soul_Glo]

Cabin filter is clean as a whistle - done 3 months ago. Checked it and all good.

Re-gas was done last month as a/c was not getting cold enough.

Heater-evaporator replaced under warranty 8 months ago because aluminium oxide was flying out the vents and it was like a snow storm...

Now suspecting a bad heater core...

[old grey steve]

Don't know what vehicle you've got and I know it's difficult to describe a smell but when we check various smells reported in cabins by customers apart from the stated pollen/cabin filter heating issues described above there are some other areas that we look at from time to time that actually solve the problem and are worth looking for as describing the issue you're experiencing can be difficult a put your finger on and we've learnt to never rule anything out.


Leaking rocker cover gasket, oil will run down and eventually make contact with the manifold which will burn and with the air flow of the vehicle the smell will naturally be pushed back and will unless shut of vent in to the cabin.

Cracked exhaust manifold/exhaust flexi's black soot residue that an under bonnet inspection with the aid of a torch would prove useful, small or slight loss of power, slightly different exhaust / engine tone all signs of a problem on the 325 330d's for instance as well as the 5 series units with the same power plants we've seen a fair few cracked manifolds that emit exhaust fumes which eventually vent into the cabin, the exhaust flexi's also can break up through age or if the cars low enough and you go over enough speed humps with the pressure of the exhaust grounding and the manifold bolted firmly in place the flexi takes the brunt of the force, telltale rattle or a visual look with the aid of a ramp and torch will help.

Rare but also the gaskets on the manifold can over time leak slightly and also worth looking at is the vehicles vacuum pump which can leak and emit enough oil to create a problem too.

[Soul_Glo]

Thank you I really appreciate the advice.

[Soul_Glo]

Took it to dealer who said they cannot help. They said that "smells" are not covered under the warranty and all they could offer was an air con bomb. Obviously they want me to line their pockets so they can investigate it all. I have AUC warranty and they said that it would not be covered... not sure where I stand now.

[Exxie]

Take a look at your windscreen washer fluid. I had a horrible smell and worked out that the cap popped up during a heatwave and the fluid went rancid. Was not pleasant...

[wuntunmein88]

I have the same problem with my 335i after turning off A/C. Does the air con bomb trick work?

[wallsmk2]

get a £10 aircon bomb from Halfords and see if that solves it

[Soul_Glo]

Nah the a/c bomb can only do so much. You need two a/c bombs and don't run them together but run them one after the other! What really helps is using the REST button - advised by someone else off here. Cannot remember the thread. The theory being that it helps the moisture in the vents to evaporate rather than just cool down, sit there and grow bacteria. If you don't have a REST button then putting the heat on for a few minutes before you leave the car might work. I hit REST and let it do its job for 15 minutes at the end of the journey. I don't always need to use it though and sometimes it is okay. Last point in hand is cleaning or changing out the micro filter more often. I change mine once a year but hoover it out or clean it every 6 months.

If it is really bad and none of the above work then the bacteria may be on the a/c evap itself and the best method would be to access that and give that a clean out.

[rhysh1990]

Mines never smells unless i have the aircon on then turn it off - it stinks! If i dont put it on its fine, with it on its fine but as soon as i turn it off it stinks for a few minute. Would one of them aircon bombs help?

[djgandy]

Originally Posted by rhysh1990

Mines never smells unless i have the aircon on then turn it off - it stinks! If i dont put it on its fine, with it on its fine but as soon as i turn it off it stinks for a few minute. Would one of them aircon bombs help?

Yeah that's the smell. No idea what it is or where it is from.

[Terryk]

as Silver Fox says it's from the moisture. this phenomenon happens to all the cars I have driven, i.e. vw polo, peugeot 307, ford focus, renault megane, vw golf, hond jazz hybrid etc. I think thought that inside my bimmer it's a more tolerated situation. I use annually a/c cleaner spray from 1Z too.