I recently bought a Mini during the winter months and didn't try out the AC cooling when buying; only tried the heating which works fine. Today it was warmer and it got hot inside the car so I turned on the cooling and immediately there was a horrible smell, a bit reminiscent of vomit. Very unpleasant. The smell did not appear to get any better over time so I switched off the cooling. Then there was no more smell. What could be causing this and how to fix it?a

 

I did remove the air filter (located below the glove box). It looked perfectly fine and did not smell at all. So how to diagnose this problem further?

 

Forums suggest spraying Lysol in the air intake... but where is this located?

 

I'd check the cabin air filter area well and also make sure there isn't a dead animal in the system anywhere. When I worked at the dealer we pulled a lot of big rats out of the cabin air filter areas/vents. Check the vents, etc. It can happen. Could also be mildew, etc. Some more info HERE.

 

also check that the condensate line isn't blocked ... do you see the steady drip of water from under the car when a/c is running? If not the line is blocked and that water is sitting someplace!

 

FWIW, the A/C in my 2009 Clubman S smells faintly of fresh bandaids when I first turn it on. Quite pleasant and nothing like vomit.

 

Remove cabin filter located below glove box. Run full blast and spay a whole can of disinfectant spray. Replace cabin filter with a new one. Make sure it's carbon filter and not regular.

 

Open the hood take off the shroud covering the battery, check for anything in this area as this is where your fresh air comes from. Leaves, water mold, bugs rodents...Sad but true, fresh air from around the battery!

If you put your AC in fresh mode, you will actually see the top of the cabin air filter. In recirculation mode, the door closes over the filter.