Initial 'smell' from aircon

DublinWriter

Driving an '03 BWM 320td.

Lately, I switch on the aircon, and I'm greeted by a horrible stale smell for the first few seconds. Everything is fine after that.

Answers on a postcard anyone?

Bixx

Hey I've done a bit of work with air conditioning units for buildings so I know a bit about it. First of all a lot of the refrigerants can have a smell like ammonia - can be mistaken as gas - so you may have a small leak in your system. The disappearance of the smell could then be explained by the fresh air coming in and diluting it. The other option is that there may be something stuck at the fresh air intake. Open the bonnet and see if you get a smell. If you do see if you can see a dead something or a lump of something around the air intake. Don't know how much use this will be. Good luck.

DublinWriter

Thanks dude...that's exactly what it smells like - ammonia! I just couldn't put my finger on it.

I'll get them to check it out next service.

crosstownk

Keep an eye on your A/C performance - if it becomes less effective with time then you are most likely loosing refrigerant from the system.

There are auto A/C specialists who can check it out a lot cheaper than the BMW main dealer.

bazz26

This is a common enough problem with air conditioning that is not used on a regular basis. In countries like Ireland air conditioning tends to get very little use except on the few warm days we have now and then.

Usually this stale type smell comes from the build up of bacteria in the filter or in the ventalation system itself.

AMurphy

I'd suggest a buildup of bacteria on the accumulated dirt and pollen in the evaporator (coler). I'd not suspect a leak, as it woudl continue to leak and be very inneffective very fast.
The reason you get an initial smell is the bacteria only build up (grow) when the evaporator is warm, ie, overnight, so on switching it on for the first time, you get eitehr a bloom of gas and/or spores. These can leave you unable to breath and gasping (like ammonia) in bad cases.

Leaks usually occur in the joints between parts or between rubber to steel piping, or from the complressor itself and not from the evaporator.

\m/_(>_<)_\m/

DublinWriter wrote:

Driving an '03 BWM 320td.

Lately, I switch on the aircon, and I'm greeted by a horrible stale smell for the first few seconds. Everything is fine after that.

Answers on a postcard anyone?

probably something as simple as the pollen filter