[C.J]

I've been getting a whining noise from my belt this week (I had the belt replaced last year so I didn't think it would be it again). The garage say the bearings are shot on the AC pump. Which is fair enough.

My question is, if the AC pump was causing the belt whine, would it be all the time or only when the AC was on? Do the bearings still turn (via the belt) even when not engaged?

Also, any idea on cost?

12th April:

25th April:

[kiel_dafo_kenyg_as]

If the A/C isn't on the pulley spins freely.
Never heard of an A/C pump bearing failure. Don't they outlive the car usually?

[C.J]

Originally Posted by whiteblue

If the A/C isn't on the pulley spins freely.
Never heard of an A/C pump bearing failure. Don't they outlive the car usually?

Depending on wether your car has Co² package or not you need a belt with different length. Maybe they installed the wrong belt last year. Without Co² package the belt has to be 6millimeters shorter (4PK 830)

Is the AC pully attached to the AC pump? Could it be that pully with a faulty bearing? So the whole pump must be replaced?

[C.J]

Just added a video to first post.

[jamesmurray]

It will most likely be the bearings on the tensioner that are worn out;

http://www.eurocarparts.com/ecp/c/BM...bd4af15&000112

James

[peter2704]

my A/C went noisy on me so fitted a shorter belt to by pass the pump,now quiet but no A/C,how much for a new pump inc fitting?

[C.J]

Originally Posted by peter2704

my A/C went noisy on me so fitted a shorter belt to by pass the pump,now quiet but no A/C,how much for a new pump inc fitting?

Was yours noisy all the time (with AC on/off)? Like my vid?

I got quoted £995 today from my indi. I'm just not convinced it's the pump.

I have BMW warranty so I'm hoping it's covered, will take it to them soon.

[Calluhan]

Originally Posted by C.J

Was yours noisy all the time (with AC on/off)? Like my vid?

I got quoted £995 today from my indi. I'm just not convinced it's the pump.

I have BMW warranty so I'm hoping it's covered, will take it to them soon.

Wow that's a lot of 'fitting' costs! A brand new Denso pump is less than 300 quid so I wonder where that price comes from?

[C.J]

Back with my indi today to triple check it's the AC pump. Typically it was bloody quiet this morning.

I've booked it in with BMW too, as if it is the pump, i'm confident it'll be covered under warranty (at least it's not listed as an excluded part).

[Iyrix]

My AC pump was noisy for ages, then on the way to the garage it totally failed.

[C.J]

Originally Posted by Iyrix

My AC pump was noisy for ages, then on the way to the garage it totally failed.

What happened when it failed? What were the costs?

[peter2704]

mine sounded like a supercharger whine through the rev range from inside,outside it sounded rough,first i thought it was an idler pulley ,but they felt ok,so did the short belt to bypass the ac pump and the car became the quietest it had ever been since i owned it.

[peter2704]

yep sounded like yours.

[C.J]

Originally Posted by peter2704

mine sounded like a supercharger whine through the rev range from inside,outside it sounded rough,first i thought it was an idler pulley ,but they felt ok,so did the short belt to bypass the ac pump and the car became the quietest it had ever been since i owned it.

Thanks, yep, supercharger is the sound I can hear too.

[Iyrix]

Nothing major, pulley shattered into 1000 pieces and belt came off. I was lucky to have pulled up to the garage. Open the bonnet and it go in front of me!

[C.J]

BMW had it yesterday. Confirmed it's the AC compressor. Earliest booking is May 7th

Today however the noise has got considerably worse after a 60mile drive. Worryingly bad. Sounds like a propellor.

I can't speak to BMW now until Monday, any idea if it's related or what it sounds like? I'm not moving it until I know.

[kiel_dafo_kenyg_as]

Originally Posted by C.J

BMW had it yesterday. Confirmed it's the AC compressor.

I've edited my prior post cause I was wrong about the belt size (4PK830 is for diesel only)

I don't understand how the A/C compressor can make a noise when the A/C is off. Does the noise signature change unter load (A/C on)?

[C.J]

Originally Posted by whiteblue

I've edited my prior post cause I was wrong about the belt size (4PK830 is for diesel only)

I don't understand how the A/C compressor can make a noise when the A/C is off. Does the noise signature change unter load (A/C on)?

It does change pitch when AC is switched on, but I guess the belt spins faster?

They said the AC pulley is constantly spinning, as it doesn't have a clutch, and electronically it turns on with the button. Either way, it's under warranty fortunately.

I just don't know how bad it'll get in 10 days.

[peter2704]

keep us posted ,also find the cost if poss .Want to get mine back in action this summer