[DCHM]

Hi everyone,

I have an 2015 i30, CRDI and a persistent problem with the smell from the vents. The forum threads I've found mostly talk about the smell from the A/C when it's turned on, but my issue is the opposite. There's a really nasty smell that appears the moment the A/C is turned OFF (but only if AC was running earlier). If I just start the car and do not turn the A/C, there is no smell. If I then turn on the A/C, still no smell. But the moment I turn A/C off, the smell is really bad. It doesn't matter how long the A/C was running - even if I activate it just for a few seconds (even accidentally, literally click A/C button on then off), the very strong smell appears and would not go away for at least half an hour.

I tried aircon bombs (smell returns in full after a day or two), chaniging pollen and A/C filters (again, smell returns very quickly).

Any  idea what's causing it and how to fix it?

Would be grateful for advice! Thanks

[sundiz]

Ozone treatment might help, if the smell is coming from organic matter. What sort of smell it is? Chemical, BO, mold?

[DCHM]

The smell is really hard to describe - I'd say it smells like concentrated dust (like an old vacuum cleaner might smell) and the smell is a bit wet too. But the filters were changed, and no difference. As I say, the smell only appears if the A/C was switched on and then off - so something must be happening as the A/C starts working. If I don't switch the A/C, or if I switch it on and keep it, there are no bad smells whatsoever. I guess that could rule out some potential issues - as the smell is not constant but appears only in a partiuclar setting?

[Lorian]

Check the aircon drain pipe underneath - probably blocked causing bacteria build up.

[martyni30]

Have you had the Pollen filter changed recently. I had the same problem with a dusty smell when I turned the AC off,. Replacing the pollen filter cured the problem for me.

[DCHM]

Thanks - I did, yes. Didn't help in my case though

[CraigB]

Sounds to me like the evaporator coil needs decontaminating, you'll need to get that done through an aircon service shop.

Also check for debris in and around the air intake vents, matter can build up in there if parked under messy trees.