[gkroegman]

2009 328i... not a "problem" (yet) but something that I wonder about.

If I have the car just on, parked or driving, usually the engine fan is fairly quiet and not really noticeable.

However... as soon as I put the AC on, it goes to MAX right away. It sounds like a freakin jet engine. Coolant is fine, AC blows cold, car drives perfect (absolutely no difference). I can drive to the store or take it on a long road trip, it's the same no matter what.

It's only when the AC is on, whether its blowing a tiny bit or full force. When the compressor is running, that fan is whirring like crazy.

As soon as I turn the AC off (again, if I'm parked, driving, doesn't make a difference) the fan returns to normal and it once again sounds like an automobile and not a jet.

Is this normal?

[Tom K.]

Originally Posted by gkroegman

Is this normal?

Yes, but only if you turn it on by pushing the "Max" button. If you push the "Auto button and your temps are set around 70o F, the fan speed would normally not go to maximum.

Tom

[gkroegman]

Thanks for the quick reply!
I've never heard another car this loud, so it made me curious. A little bit of an increase in fan noise is expected, but not going full force. It's actually kind of embarassing when stopped because other people look at me like my car's gonna explode!
I don't use Max or Auto, I just use the incremental button. I can have it on the lowest setting or the highest, there is no change. I usually have the temp set between 60-65.

[Tom K.]

Originally Posted by gkroegman

Thanks for the quick reply!
I've never heard another car this loud, so it made me curious. A little bit of an increase in fan noise is expected, but not going full force. It's actually kind of embarassing when stopped because other people look at me like my car's gonna explode!
I don't use Max or Auto, I just use the incremental button. I can have it on the lowest setting or the highest, there is no change. I usually have the temp set between 60-65.

I suspect the problem is your temp setting. When set that low, the Auto Climate Control will most likely call for a high (and noisy) fan speed - even in "manual" mode.

Try setting the temp around 70o and pushing the Auto button.

Tom

[MiniXP]

Originally Posted by gkroegman

Thanks for the quick reply!
I've never heard another car this loud, so it made me curious. A little bit of an increase in fan noise is expected, but not going full force. It's actually kind of embarassing when stopped because other people look at me like my car's gonna explode!
I don't use Max or Auto, I just use the incremental button. I can have it on the lowest setting or the highest, there is no change. I usually have the temp set between 60-65.

Originally Posted by Tom K.

I suspect the problem is your temp setting. When set that low, the Auto Climate Control will most likely call for a high (and noisy) fan speed - even in "manual" mode.

Try setting the temp around 70o and pushing the Auto button.

Tom

I think you both may be talking about different things.

gkroegman, are you talking about the radiator fan going on full blast or the ac/climate control fan?

The radiator fan may just turn on high to cool the car since it is working harder when the AC is on. Probably depends on your ambient temps. Is it pretty hot where you are when this happens?

[Billit335]

Or your water pump may be taking a dump, slowly.

[Efthreeoh]

OP. The engine cooling fan (the device located on the radiator) goes on high speed when the AC compressor turns on to ensure maximum cooling of the AC system. When the car is traveling at high speed the fan will slow down, but you'll not notice it since your are traveling at freeway speeds and road and wind noise overcome the fan sound.

If it is concerning to you, you can have the car scanned with a BMW scan tool. If there is some abnoramality with the engine cooling operation, there will be at least one, or more trouble codes, stored in the ECU. These cars should be scanned periodically for finding issues with the various systems of the car prematurely before they become a breakdown.

[este]

Originally Posted by Billit335

Or your water pump may be taking a dump, slowly.

+1 mine was doing the same before it died on me.