I have the same exact problems you are having. AC noise is from the blower motor. the bearing is going bad on the motor and the motor needs to be replaced. part is like 90 bucks but the labor is expensive. you are better off DIYing this but it is not easy to get it out or installing a new one.
Check out this thread http://forum.e46fanatics.com/showthread.php?t=507678 there is alot of info on there

But as far as the stalling out issue there are alot of ways to get rid of it. It could be anything at this point. some people replace their spark plugs and it goes away, some people clean out the icv valve or whatever. search "rough idle" and you can see alot of info on it.

 

Had the same issue before. problem was low freon caused by a leak in the evaporator. it could be the compressor struggling.

 

It may be something to do withyour freon.. Butim not too sure..

I'm also having some issues with my AC at the moment, it makes an hissing sound when I turn the snowflake on, and a slight groan. If I turn the snowflake off than all is silent, just the sound of wind blowing.

Also, when I first turn my AC on, the blower speed varies going from low to high and low again and the. Settles down to my settings.. What's with that? Fsr failing?

 

It may be something to do withyour freon.. Butim not too sure..

I'm also having some issues with my AC at the moment, it makes an hissing sound when I turn the snowflake on, and a slight groan. If I turn the snowflake off than all is silent, just the sound of wind blowing.

Those are the early symptoms before it eventually runs out of freon and the noise will get louder

Also, when I first turn my AC on, the blower speed varies going from low to high and low again and the. Settles down to my settings.. What's with that? Fsr failing?

its cheaper to replace the final stage unit first, im pretty sure it'll fix that. or worst-case it could be the blower.

 

First of all, screw you for living in a climate where you'd need ac in Feb. j/k

Sounds like it's low on charge. Variable displacement compressors seem to groan when the charge is low. IF YOU'RE NOT EXPERIENCED CHARGING an a/c system, find someone who is. It's likely that you'll damage the system and create major problems for yourself if you screw it up.

 

First of all, screw you for living in a climate where you'd need ac in Feb. j/k

Sounds like it's low on charge. Variable displacement compressors seem to groan when the charge is low. IF YOU'RE NOT EXPERIENCED CHARGING an a/c system, find someone who is. It's likely that you'll damage the system and create major problems for yourself if you screw it up.

+1

Its -10 outside here

 

I'm having the exact same problems you are. As for the weird sound with your a/c, you could need a new resistor for the a/c fan, or to get it recharged.


As for stalling on cold starts, I'm about to replace all 6 spark plugs and all 6 ignition coils. Others have said to clean your IACV, and that couldn't hurt at all, but it would have to be really clogged up for it to be causing your car to stall out. Also, you said your car runs fine otherwise, so you're not stalling out any other time your car is idling.

 

Thanks for the replies so fast. The noise disappears when I turn the snowflake off even if the fans are running. I'm not that mechanically inclined but isn't the blower fan controlled by the fans being on or os that a different fan?

I asked a mechanic to check the freon and he said it was "ok".

 

I will drop by the work shop next week, will update soon..

 

I've had the same groan almost winding noise, like others here it was because I was low on freon.

 

I have same symptoms as post 1... only when compressor is cycled on... not the fan... I am leaning toward low R134a ... will buy/borrow some ac gauges and check high and low pressure.

 

Just wanted to update. I had the same Chewbacca sounding noise at low rpm 1500-2000. Took it to my local shop and I was 1/2lb low freon. Low and high showed normal. Hope this helps some of yall out. Aloha

 

LOL @ 'chewbacca'. but very accurate. i had that as well on my 330ci. also noticed a high pitched squeal which occurred only right near redline. turned out both were related... my compressor failed catastrophically after a few thousand miles (it froze and actually stopped the engine while sitting at a stoplight). upon replacement, both noises were gone.

 

Had this issue and found a cheap fix...

I have an e90 325xi with the N52 motor, and I had the AC on groaning issue. I had 64k mi on it, and my service advisor told me to try to put a new serpentine belt, e90s don't have a separate AC Belt, but it may apply to an e46 too.

Anyways replaced my belt and viola! groaning is quieted down 99.8% So you only here what I would considered a normal operational tone from the AC.

$50 belt vs compressor or new blower fan.

UPDATE: Noise came back but is quieter than before, so I guess I have a freon leak. The belt helped a little, but I guess it will need a visit to the dealer.

 

+1 on the above, mine was low too

I have an e90 325xi with the N52 motor, and I had the AC on groaning issue. I had 64k mi on it, and my service advisor told me to try to put a new serpentine belt, e90s don't have a separate AC Belt, but it may apply to an e46 too.

Anyways replaced my belt and viola! groaning is quieted down 99.8% So you only here what I would considered a normal operational tone from the AC.

$50 belt vs compressor or new blower fan.

UPDATE: Noise came back but is quieter than before, so I guess I have a freon leak. The belt helped a little, but I guess it will need a visit to the dealer.

UPDATE 2: Took it into the dealer my e90 N52 was low on freon by .54 lbs. I am going to just top it off myself the next time it happens, with a quick shot from a diy can of freon from walmart. Not accurate but I do not plan on overfilling it or maxing it out, .5 lbs is very little and should get rid of the noise with a quick spritz of freon.

 

Sorry for resurrecting an old thread, but I just wanted to add more data for those searching for moaning or groaning noises when the compressor engages.

My 325Ci was making these noises, but only during the winter months and only until the car was warmed up. It's been making these noises for the past 5 winters, but it still blew cold in the California 109degF summers so I put it off. I finally found a guy I could trust with my car, we checked it, and it was 0.98lbs low.

We did an evac and recharge, no more noises, it's even colder now and all is well.

 

noise gone for now

funny this came up cause last weekend I shot a can in my system, and my noise went away as well. The low side was reading at the bottom of the range, and it went to near middle of the range for my gauge at the ambient temp.

So far so good.

 

I am wondering if your groaning is also when the AC is NOT on ? I read somewhere that a fuel filter (mine has a built in regulator on my 03 325I ) may be a problem . Mine is moaning very annoying and also runs out of gas at just under 1/4 tank. I ordered a new filter and will do the install this week. I think mine is the factory filter with 116 k on it.

 

Mine is making the same noise. But I think its the resisto and/or blower motor. The blower would intermittently shut off at low fan speeds. It would come back on when I change air modes or change fan speed.

 

I had to change my FSR 3 years ago, BMW redesigned it.
Two years later it was the squirrel cage fan.
Three years later I needed a recharge of freon.
The fan is pricey, but you can use the one from an X3 which is cheaper by far.
Find the thread and you'll get the part number and instructions. Pretty sure I posted in it so try Advance Search with DEADF15H as a poster and blower motor or fan in the search. The fan removal takes some patience, but it's a DIY for sure.