[code600]

So I have this problem where my fan spins very loud when you turn on the AC. It spins loud only when the car is idle, if I am driving around then the fan calms down, if I stop somewhere it goes loud again. Before you say that it's suppose to be loud, it's not, because I compared it to my brothers and his runs twice as quiet as mine. Mine really sounds like an airplane. Also the AC won't turn on at all when it is to hot outside, I noticed it doesn't turn on when the temperature outside is over 97F. Water pump? Or thermostat? Is there a way I can test which one it is besides going to the dealer?

[Turb0Surge]

Your brothers probably wasn't warmed up? I don't know what else to tell you because both mine and my brothers are loud also. Sound like a jet taking off.

[mundo74]

Sound like Your condensing pressure is too high. Get a ac manifold gauge to monitor the high and low pressure. If your high pressure is say below 300 psi then it could be a faulty press transducer. The way it works is that the fan varies its speed to keep the condenser pressure in range. If the pressure sensor is bad it could be giving the hvac computer false readings. If the hvac computer sees the condenser press is too high it will turn off the compressor to avoid an uncontained failure.

[code600]

Originally Posted by Turb0Surge

Your brothers probably wasn't warmed up? I don't know what else to tell you because both mine and my brothers are loud also. Sound like a jet taking off.

Trust me, my brothers fans have never been this loud like mine, ever. Just when you turn on ac the fan spins pretty much at full. I didn't find it a problem since I didn't use ac last year but it's been really hot lately and I need ac and plus people always telling me whats wrong with it. I mean if you put my car next to an airplane I think my car would be louder. I will probably check the pressure tomorrow.

[mike3000fl]

mine does this too, just like you describe. full blast jet fan roar when the ac button is on. shuts off a few seconds after i turn it off.

it only behaves this was over a certain outside air temp. around 86. in the cooler times of the year it functions fine.

i have read that the fan is designed to kick on so that the ac system functions optimally when it is very hot outside. sort of like how on a home ac unit the part of the system that sits outside has a fan to draw air through the coils and remove heat.

interested in seeing your ac hi/low manifold pressures... please post the result if you do check it.

also..... i have a bad thermostat. it is stuck open so I haven't bothered replacing it. you can pull codes for free at autozone. Write down the code's P number because their scan tool doesn't show the proper fault description. I had to look it up online with the P code. the employee told me it was something crazy like a cruise control fault.

[Anon007]

Originally Posted by code600

So I have this problem where my fan spins very loud when you turn on the AC. It spins loud only when the car is idle, if I am driving around then the fan calms down, if I stop somewhere it goes loud again. Before you say that it's suppose to be loud, it's not, because I compared it to my brothers and his runs twice as quiet as mine. Mine really sounds like an airplane. Also the AC won't turn on at all when it is to hot outside, I noticed it doesn't turn on when the temperature outside is over 97F. Water pump? Or thermostat? Is there a way I can test which one it is besides going to the dealer?

At least yours only sounds like an airplane, mine sounds like the entire navy is taking off

[Teohenwhy]

Mine does the same thing as well as my friend's 328i when he first bought it from the dealership. He actually took it back and they showed him with the other cars on the lot that is normal only when the outside temperature is pretty hot.

[Tim07e90]

I agree. My car does this as well. It was about 98 degrees here in So Cal on Sunday and while I was taking pics of my car I noticed how loud my fan was when my AC was on. Good to see other owners have this same concern and that it's normal.

[sebaNYC]

good to know that im not the only one, i was worry about it, actually i was trying to avoid use the AC for long periods

[Sara]

I had that problem in my 2006 325..in my case it turned out to be the "e box" it was doing its job but it was just being loud about it so they replaced it under warranty and everything was quiet again.

[BOBKUR]

Normal Noise.

[dcat151]

I've never had this issue with my BMW, but my wife's Odyssey does exactly what you describe: with the a/c on the fan is really loud when the car is idling, but not when it's moving. Hers has been doing this ever since we got it and we haven't had any issues resulting from it. I just chalked hers up to Hondas being less refined.

[termikaustin_84]

i have 07 328xi and it makes the same annoying sound, but my friens has 06-325i and has no sound. he was surprised how a newer car make so loud sound