[satz]

I've noticed this a couple of times on my car.. Say I've driven it with the AC on (HVAC set to Auto), and then switched AC off just before I parked it.

Then when I start it up, say 30 minutes later, the AC seems to be on, even though the AC light is off. The air is too cool to be just fresh air (and in fact usually the car pumps out hot air because of the engine bay heating up).

Switching on the AC and then off again doesn't change the air temp, nor can I hear any engage/disengage from engine bay (nor any rev change).

Only if I switch drive experience from Sport Indiv to Comfort, do things go back to normal...

Seems a strange and rather specific fault. Any ideas? I'd ask the dealer, but this problem doesn't repeat itself often

[g0t2bmiirii]

Originally Posted by satz

I've noticed this a couple of times on my car.. Say I've driven it with the AC on (HVAC set to Auto), and then switched AC off just before I parked it.

Then when I start it up, say 30 minutes later, the AC seems to be on, even though the AC light is off. The air is too cool to be just fresh air (and in fact usually the car pumps out hot air because of the engine bay heating up).

Switching on the AC and then off again doesn't change the air temp, nor can I hear any engage/disengage from engine bay (nor any rev change).

Only if I switch drive experience from Sport Indiv to Comfort, do things go back to normal...

Seems a strange and rather specific fault. Any ideas? I'd ask the dealer, but this problem doesn't repeat itself often

I've noticed this with my last car that i had (Infiniti).. my theory is the car goes by what the temperature is outside and regulates it to be inside depending on the temperature you set it. For example if it's like 80 degrees outside and you turn on the fan itself and leave the temperature at 72 degrees and shut off the a/c button, the car will still blow cold air because it wants to regulate the temperature to what you want it to be (in this case 72 degrees). I think that's how it works. So unless if you lower it all the way that's the only way you'll get the cold air. Take this with a grain of salt, just a theory, maybe other people here can confirm it

[Wgosma]

You won't hear or feel the compressor engage/disengage as it's a variable volume compressor - common design used on many modern cars. The compressor is always 'engaged'- this may be why you sense cool air flow even with a/c switched 'off' when controls are set to 'auto' mode...that's my guess.

[Fast400]

So there's a couple things that take effect on the AC being on. I believe when you turn the button off, it has off a period of time while drive (ie 5 min). If you turn it off, park, then come back and drive off it will stay on the rest of that timeframe. The other thing that has an effect is the setting in the climate control settings (idrive) is where you've set the two center vents (cold~hot). If they're set to fully cold, I've found my a/c will try to accommodate even with the switch off. Hope this helps.

[freshxdough]

AC can turn on in the background to dehumidify the air. I have AC on all the time at my preferred temperature. In newer BMWs there's really no reason I have the AC off. You won't feel the ac kicking on and off. MPG difference is minimal if any compared to older vehicles witch clutch compressors.

[satz]

hi guys
many thanks for the responses.

Couple of related questions:
1. do the X3s have the humidity sensors on the windscreen? If so, does that automatically activate the windscreen defrost (or do I have to switch on AC?)

2. Would it wear out the AC compressor sooner by running it all the time?

cheers

[Alias1431]

Originally Posted by freshxdough

AC can turn on in the background to dehumidify the air. I have AC on all the time at my preferred temperature. In newer BMWs there's really no reason I have the AC off. You won't feel the ac kicking on and off. MPG difference is minimal if any compared to older vehicles witch clutch compressors.

Kinda random question, but sometimes my climate control will automatically turn off my cabin air recirculation button, all by itself. I have the iDrive 6.0 option to "freshen" the cabin air or whatever turned off.
It's annoying, I'll get a strong whiff of exhaust at a light or something, look down, and it's off. Do you know why it does that, or how to stop it?

[freshxdough]

Originally Posted by Alias1431

Kinda random question, but sometimes my climate control will automatically turn off my cabin air circulation button, all by itself. I have the iDrive 6.0 option to "freshen" the cabin air or whatever turned off.
It's annoying, I'll get a strong whiff of exhaust at a light or something, look down, and it's off. Do you know why it does that, or how to stop it?

Recirculation is automatically set to give fresh air every so often.

[Fast400]

Here's a video that talks the point a little bit. It's definately about cutting down moisture in the evaporator of the A/C system.