Hello all,

First and foremost, I have searched and read up on this topic but a lot of the threads have either gone unanswered or have died before the real question was answered.

I just purchased an 04 MCS and I love it, the car is flawless however the other day I noticed that the car makes this really ugly sound whenever I turn the AC on. The car makes this whirring, grating, kind of sound; it almost sounds like what a coffee maker sounds like when it's finishing the brewing process lol. It's pretty noticeable and rather annoying and it only comes on when I turn on the AC. If I turn the AC off, the noise persists until I turn the car off and let it sit for a while. Any Idea what this could be? I want to be able to diagnose the problem before paying MINI dealership to do it for me

Thanks,

 

Look under the hood while it is running and noisy. You should be able to figure out if it is the AC compressor or the radiator fan, both of which are high on the suspect list.

 

I shall do that right now, but what exactly is it I should be looking for?
I also forgot to mention that the AC does work and blow cold while it makes the noise

 

They are both near the front, but the fan should give you a clear sound since it isn't buried. It would help if you can listen while someone else turns the AC on and see if you can figure out where it comes from. I am using general car knowledge since I have only had the mini about 2 weeks, but the compressor probably is on the left side front buried. Fan is on the radiator. There should be enough seperation to determine if you are lucky.

 

alright thanks,
I'll try to see what the deal is

 

I'm guessing that the ac clutch is enguageing...causing the rattle, then not releasing, since it my be partially failed. Just a guess. Another thing to look at might be the belt and pullies on the belt...a bearing on one could be failing, and when extra tension of addeding the load of the ac..it starts to rattle.
Could you describe the "racket" a bit more? Is it a squeeling sound, a rattle, a grinding sound, or even a scraping sound? You said the car was quiet till you turned the ac on right....then the noise starts...and it stays on after the ac is off, correct, then after the sits, it is quiet when you restart?
What is the car's cooling fan doing? Depending on the sound, you may be hearing the ps cooling fan, which is under the car activating...they tend to get gummed up with sand/debris, and the bearings can fail, sometmes siezing....
The sound of the noise or racket is important, and like was said, open the hood, with the ac off, listen, then turn on the ac...and see if you can tell where the sound is comming from. The ac compressor is on the pax ( us) side, at the bottom of the serptine belt.
The ps cooling fan is on the bottom, center, a few feet back......

 

I'm going to make a video and record the sound for everyone, that's the best way I can describe the sound. Thanks for the help guys I really appreciate it

 

My car made a similar sound last year and shortly after stopped blowing cold air. I had the a/c recharged and the problem was solved. No more "coffee brewing" sound and now it blows cold air. I hope it's something simple like a recharge to fix your problem.

 

i'm hoping it's the same sort of issue as well, I will upload a video later so stay tuned! how much was your ac recharge btw? did you go to a mini dealer?

 

I am glad things worked out for you but I just want to point out that fixing a leaking A/C system by putting in refrigerant is exactly like fixing a leaking boat by pumping all the water out.

In the end, unless you find and repair where it is escaping, nothing is really fixed except the symptom of no cold air coming out the vents. (I understand that is all anyone including myself care about..)

Just in case the waranty is close to expiring and you had it fixed for free, make sure they really repair the issue, not the symptom.

 

I agree. The shop did some sort of leak test to see if the refrigerant was leaking which it wasn't. They filled it back up again and a year later, everything is still fine. The car is an '04 and had lived previously in Florida and California so I assume the A/C was used regularly. It didn't surprise me that it needed a recharge.

The cost was just over $100 here in Canada and I had it done at a local mechanic down the street from me. I've had pretty horrible service at our MINI dealer so I avoid them at all costs.

 

I have the same problem as the OP. To add to the mystery, when I turn on the A/C the voltage drops from 13-14V down to 10-12V on the voltmeter. Since I don't want to drain my battery, I have been leaving the A/C off. But I need to get to the bottom of this.

 

You are most likely seeing the voltage drop due to a change in the idle...after a few minutes, it shoul re-stabilize higher... I know after a few stats and short drives, it takes a bit of time for the voltage to return to normal...
It is possible the alternator is very weak...and the cobination of the cooling fan, interior fan, and the lower idle combine to overload it, but since the alternator can bew a few hundread $$ plus install, I would trouble shoot it, and do a load test before swapping it.