My car is an 03 MCS with 100Kmiles on it. Starting about a month ago, a whining noise appeared when the A/C is on. I can hear it around 2K rpm (softly), but it gets louder and more pronounced once the revs start passing 3K rpm. While holding the rpms high (e.g., ~4K), if I hit the A/C off button, the noise disappears instantly. So, it is rpm dependent, but irrelevant to whether the car is moving or not (can reproduce it while idling).

When I described the problem here, it was suggested that it could be the A/C compressor since it is an rpm dependent whining that comes on only when the A/C is on.

Today, after an oil change at an independent mechanic, I asked him to listen to it. After listening for 5-10 seconds, he said that it's the supercharger, because A/C puts extra load on the supercharger making it more pronounced. He said that he's seen them go bad on the early year cars and did 3 in September.

He's been wrong in the past in his initial, quick diagnoses; so, I would like to ask the NAM guru for opinions here. Can it be the SC? If so, what other symptoms should I look for to confirm that it is? Nothing sounds out of ordinary until the A/C comes on.

I dont have any mods except the 15% Webb SC pulley (since 54Kmiles). The crank pulley was also replaced with a stock, newly designed one, in case it has anything to do with it...

Thanks very much for your time and help in advance!

 

The supercharger will make rattling sounds as it dies.


Take a look at this thread.
https://www.northamericanmotoring.co...ater-pump.html

 

Thanks for the link to the thread. May be I should record the noise and upload it to youtube. I am not sure if it's rattling or not. Let's say it is and the SC is dying, would you expect the pronounced, rpm-dependent whining noise with the A/C?

 

Well, my a/c compressor wines, but I don't hear any rattles from my supercharger. But I'm planning on changing the fluid in the supercharger this winter as a preventative measure. After this, we'll see if the a/c still whines, or if it was the s/c.

 

My guess would be that the A/C clutch bearing is going bad.
You might want to investigate on your own by using a long screwdriver or Mechanics Stethoscope to listen to various parts (such as A/C Compressor or Supercharger). If you have to use a screwdriver, place the tip of the screwdriver on the suspect part and put your ear on the end of the handle to hear the noise coming from the part. Do this carefully, with the engine running, with and without the noise occurring. You should be able to isolate the noise to a specific part (A/C or S/C).
The stethoscope (link below) is very useful and only costs about $6 at Harbor Freight Tools. I use mine all the time. It is also a little safer than using a long screwdriver. You can probably find something similar at a local auto parts store.
http://www.harborfreight.com/cpi/cta...emnumber=41966

 

Please just buy the $6 tool and also check the water pump for noise.

 

What do you mean by rattling sounds?

Is this noise loud enough to hear while driving?

 

I am willing to try, but without having a reference point, I wont be able to tell what is normal and what's not. When I listen to a human heart, it speaks to me with every single beat, valve openings/closings, timing, etc. However, listening to a car engine is completely foreign to me.

 

Hello Volki, I think you'll be surprised how fast you will tune in to your MINI's heart.

 

When you listen to each individual part. you will be able to isolate which part is creating the whine. You will be able to hear the noise through the stethoscope.

 

Could it be a belt slipping or maybe just worn out? My old Geo did a whining noise and all I did was changed the belt. Just a suggestion...... you never know

 

Thanks for the replies. I'll go ahead and order that stethoscope and try to identify the source of the whine (and also whether the SC is rattling or not). Once I am done, I will keep it on my desk to scare my patients :D

 

most local parts stores will have that stethoscope for about the same price too.

 

Thanks! I'll make few phone calls then...

 

Hi I too have a noise coming from my supercharger. It is a "groaning/moaning" sound. I had this on my original 02 SC, which I was told by a specialist; that it was the bearings. So I decided to buy another unit from ebay, which was new-in-box, and the later teflon coated one.

On intsalling the new SC, my specialist called me and said; unfortunately your new charger has a noise too, this is down to a "high tollerance level" within the charger :(
It is real strange as it has the groaning noise again, alsmost like the bearing issue beforehand!

They replaced it with new belt, and matching JCW reduced pulley.
My old SC had a 17% reduced pulley. I am thinking that that was the original cause, for the SC to start having problems!

So here I am back to a noisy SC, only this time the groaning/moaning noise is not so loud, can be instantly heard at start-up of engine, it gets quieter oncethe engine has warmed up, which is better than my old unit, but still there and bugging me:(

can anybody help?
Dean

 

Hey Dean, how many miles were on the SC you pulled off the car and do you know how many miles it was run with the 17%?

 

about a year ago my supercharger went bad due to the waterpump drive. I have since had it rebuilt. I have the a/c whine as well and i'm 100% sure it doesn't have anything to do with the supercharger. I had the whine before my s/c rebuild and after.

 

Thanks very much for your post. I believe I have the A/C whine and not the supercharger rattle at this point.

Have you resolved the A/C whine issue? Was it the compressor?

 

check the mounting bolts on the AC I've had two customers with broken bolts.

 

Hi above!
Yes it is a kind of groaning/whining sound. Somewhere I read it was something to do with an idler pulley?
I replaced my last charger at 66k Autoex. I am not sure how long the reduced pulley was on the engine, as I bought the car second hand.
I would think up to 40K.
I find it amazing having now replaced one SC with another, and this noise is still there!

Aparantly this (No2) charger is diagnosed as having a "high tolerance" level??
But the whirring/groany sound is still there after the second charger, just not as loud. Have I really been that unlucky??

 

My 02 R53 is having the same issue. I noticed this groaning sound a couple of times when using the AC over the summer. Turning my AC off would cause it to go away, and it wouldn't always occur while using the AC.

The other day, this groaning sound came out of nowhere and is now persistent at all times, whether the AC is on or off. I'm guessing it's either the AC compressor bearing or supercharger bearing. Unfortunately I can't diagnose it at the moment because I need a belt tensioner tool to get the belt off.

Perhaps I should pick up one of those stethoscopes and try to diagnose it that way. If anyone makes progress with this issue, please update this thread. I'm not driving my car at the moment in fear that I will cause more damage.

 

Hi Niko! Sorry to hear you are having the same problems as me! It is anoying me, as I recently bought another SC of ebay, which apparantly is new in box" I was hoping to get rid of the noise. To my disbelief; the groaning noise is still there, although not as bad. Can be heard when the engines starts, and then a bit more vague than before.
And this time the specialist told me it`s down to too much tolerance inside my charger? The first charger he said it was bearings?
I have a feeling it`s not the SC and something hopefully not as exspensive?

Maybe we both can get somebody on here to solve it once and for all.
I was always under the impression; when the bearings go, the SC starts the ratelling inside, and you hear like a sound of marbles ratelling inside?

Maybe it`s down to both are SC needing some OIL??

It is just strange how my specialist diagnosed my first SC, as to a bearing problem. Then with the same sound on the replacement SC only a little quieter "Groaning"; saying it is a tolerance issue??

Hopefully for your sake, you might not need to buy another SC, and it could just be that it needs a little oil, and the same with me

I drive my car daily, the specialist assured it was ok to drive with that noise. So you should be ok to driver your car. But then again is this specialist giving me the right advice?
Although I trust them as they go championship racing throughout the year, and know MINI`S very well.

I got a recent reply on here telling me to remove the belt, and move; by hand all the attachments too feel if there are any un-smooth movements.

To round things up NAM- do we need OIL? Internal Water Pump Drive? Pulley Tenosiner?...

 

I have a ticking or rattling noise that occurs at idle when i am in neutral with clutch out, any time i push the clutch in the noise goes aay but a few seconds after letting it out again i hear the ticking or rattling, sounds almost like something is loose or something.

It is only when the clutch is out and i dont hear anything while driving.

Would supercharger noises be heard while driving, and does anyone know what the ticking noise might be. Its abnoxious.....

 

The water-pump side (PTO) has 2 gears that have play or tolerance. Even new, when you turn the pulley back and forth, you can hear click click. In the long run, wear will occur and increase the tolerance and making the sound louder.

On top of that, the oil chamber is prone to leaking which will cause a SLOW death.

 

Dual mass flywheel, a new clutch sometimes temporarily fixes the issue, but the noise is pretty much a matter of time when it comes to the design. If you do a search for the words in bold you should find many more detailed threads on the topic.