[AD18]

Hi all,

I've tried searching for this problem but haven't found anything, or I'm not searching for the right thing but I have noticed when the air conditioning is in use, there is a noticeable rattle/buzzing sound.

This sound only appears when the A/C button is pressed (see video) and it builds and drops with the revs of the car. I'm not really sure what this could be, but with the hot summer we had this year it definitely became noticeable especially at low speeds.

Any ideas what it could be or certain things i should look into?

The car recently went in to have the air con blasted to remove musty smells and I saw that it was also 'topped up' but I'm sure its been going on for a while.


Video link below, just turn your volume up to hear what I'm talking about.

Thanks

[wallsmk2]

sounds like the compressor. I had a similar noise in an old 911 and it was apparently due to low refrigerant not lubricating the compressor. I have no idea about these but presume the refrigerant pushes the oil through the compressor? so low refrigerant, bad lubrication. Perhaps take it back and get them to check levels.

But with all noises, could be anything!

[AD18]

Originally Posted by wallsmk2

sounds like the compressor. I had a similar noise in an old 911 and it was apparently due to low refrigerant not lubricating the compressor. I have no idea about these but presume the refrigerant pushes the oil through the compressor? so low refrigerant, bad lubrication. Perhaps take it back and get them to check levels.

But with all noises, could be anything!

I think you could be right. Ive tried to do a bit more searching and came across this video which is pretty much the same problem. Poster stated that his was "low on refrigerant and lubrication oil for the compressor".

[wallsmk2]

sounds like it. Did you take it back to the aircon guys?

[AD18]

Originally Posted by wallsmk2

sounds like it. Did you take it back to the aircon guys?

Haven't managed to yet. It was an indy I went to, its due to go back in soon so will update with what the outcome is.

[mrbubba]

Originally Posted by AD18

Haven't managed to yet. It was an indy I went to, its due to go back in soon so will update with what the outcome is.

It's a long shot, but did you ever sort this? Just had my aircon refilled and now have the same noise when in use. I used Kwik Fit near me to do it

Edit - Took the motor out from under the glovebox and it was full of leaves. Removed leaves and nice and quiet again

[AD18]

Originally Posted by mrbubba

It's a long shot, but did you ever sort this? Just had my aircon refilled and now have the same noise when in use. I used Kwik Fit near me to do it

Edit - Took the motor out from under the glovebox and it was full of leaves. Removed leaves and nice and quiet again

I haven't unfortunately, I've been putting up with it for the moment (and using the windows/sunroof instead!) as other things needed sorting. The car is going in for some work again soon so I will mention this motor to see if that sorts it.

[mrbubba]

Originally Posted by AD18

I haven't unfortunately, I've been putting up with it for the moment (and using the windows/sunroof instead!) as other things needed sorting. The car is going in for some work again soon so I will mention this motor to see if that sorts it.

Mine was full of leaves

[AD18]

Originally Posted by mrbubba

Mine was full of leaves

Is access to this motor easy? Something the average person can do or are specialist tools required?

[mrbubba]

Originally Posted by AD18

Is access to this motor easy? Something the average person can do or are specialist tools required?

Very easy. A couple of torx screws to remove the lower trim on the glove box, then a couple more torx screws for the motor (you can see it as soon as you remove the underneath panel)
Then lift a tab and twist, the motor will fall out.
I'm not great at car DIY, but used a YouTube video

[neo61uk]

Originally Posted by AD18

I think you could be right. Ive tried to do a bit more searching and came across this video which is pretty much the same problem. Poster stated that his was "low on refrigerant and lubrication oil for the compressor".

Sorry for replying to an old thread.
Have same issue, same noise on my e92 335i n55
Air con off and its dead quiet.
Air con on and its buzzing / whining on idle / low rev.

Just did a full clean/ refill/ re-oil on Air Con but still same noise - no difference at all.
Checked the blower motor and its fine, no dirt no leafs,
Only make noise with air con on and sounds like it's rev dependent - meaning its coming from air con compressor? Not sure how do I hear it through the vents?

Any input greatly appreciated.

Anyone got to the bottom of this?

[KalevE]

Same problem here as above. Any updates?

[jacbo]

I had a horrible rattling when turning air con on, compressor was dying and replaced with brand new Denso unit.

Took old one apart and found fair bit of corrosion. Believe the system was left open at some point and eventually destroyed the compressor.

On other cars it could potentially be bearing on the air compressor clutch system?

[KalevE]

Mine was due to low refrigerant level. Went to check it this morning and there was only 190 grams in it (supposed to be 590). After filling it the noise disappeared right away. AC compressors pressure etc we’re fine and no leaks were found. They put some kind of color additive in it too so if it looses refrigerant too quick, we could see where it comes out.