[spudulike]

Hi Everyone,

I've been getting a whine from the air conditioning compressor pulley for a while and it's got annoying enough that I reckon it's time to sort it out. It's definitely the compressor pulley as it goes away when I switch off the A/C

Car is a 2006 330i with the N52 and the air conditioning compressor has the low-pressure pipe running diagonally across the front of it. It looks like there's no room to work on the pulley without disconnecting the pipe which means I'd need to de-gas/re-gas the system (something I'd rather avoid).

Has anyone successfully replaced the pulley on an N52? All of the threads I've found on the search seem to be for different engines without that annoying return pipe.

[Biginboca]

I replaced mine a few months ago. I bought the pulley from the eBay seller in Miami.

I don’t recall encountering any interfering pipes being an issue. If you mean the one I am holding here it was easy to work around:



The whole job was pretty straightforward and shouldn’t take more than an hour or so, toughest part was getting the big retaining ring for the pulley off the front of the compressor. There’s a thread on another forum that had a tutorial I followed, you should be able to find it with google. That thread had me remove the radiator fan which I would say is a must do, and very easy just one Torx screw on the top passenger side of the fan holds it in then unplug and slide it up and out of the brackets on the radiator.

[spudulike]

Thanks Biginboca, I was concerned there wouldn't be space to move the pulley off the shaft but from your photo it's clear there's enough space.

Cheers!

[rjahl]

Don't rule out a faulty compressor.

The pulley spins all of the time, regardless of the Clutch state.

I'd also check the "crazy stuff" put a little dressing or water on the belt and see if the noise changes when the belt is wet. Could be a loose belt.

I hate it when I fix something that was not broken.

[desertman123]

Yeah just take the pulley off and inspect. There's rubber dampers that may fall out lol. Those might be cracked - hopefully - makes the job easy.

As for buying a full new pulley, this is a 7SEU7C? somethin somethin Bosch AC compressor, so you can find pieces for that on eBay. Careful though, I bought a cheap ebay pulley and the bearing started screaming after a week, so I just put a stock, used pulley on there and it's been fine since.

[hOlykamOtie*]

Please keep us updated if you're able to remove/replace the pulley on e90 330i. I have the same model with the compressor pipe running in front of the pulley bolt.

[Pilarskica]

I changed mine last year in my 2009.

I used this tool to remove the hub:
https://www.ebay.com/p/AC-Compressor...0848135&chn=ps

This is the pulley
https://www.ebay.com/itm/New-A-C-Com...frcectupt=true

It took me forever to get it out because the hub was seized but I had a chain wrench like this and the hub tool and a breaker bar:

https://www.homedepot.com/p/Crescent...gaAkAfEALw_wcB

I did remove the radiator fan to give me some room. It made it a lot easier.

View post on imgur.com

If you have any questions, let me know. I also used snap ring pliers and a harbor freight puller:

https://www.harborfreight.com/automo...-pc-63953.html

[rothwem]

Okay, get ready for a stupid question here since I know very little about A/C systems:

Wouldn't a whine that goes AWAY when the AC is OFF mean that the COMPRESSOR bearings are bad, not the pulley? It would seem that the bearings in the pulley would be still relative to the spinning shaft when the A/C clutch is engaged, so that should quiet any pulley noise.

Do I have it all wrong?

Anyways, I had a whining A/C compressor and I had it recharged, which made the whine go away AND made the A/C work again. The guy at the shop said it was not holding a vacuum though, and usually its the compressor itself that goes bad on the N52 cars. He told me to come back when the A/C started blowing warm again and he'd tell me if it was leaking in the lines or at the compressor itself.

[Pilarskica]

The compressor pulley is always engaged.

This is what mine sounded like when the ac was off:

[yupetc]

To see if it's AC whine, just remove the belt and run the engine and see if it still does that whine without any of the drive components belted up.

[spudulike]

Ok, I had a good wrangle with the pipe today but it sits right across the middle of the pulley and wouldn’t budge.

I reckon I’ll be taking it to a garage since the only way to get that pipe moved is to disconnect it and that’ll mean a degas/regas 🙁

[850CSi]

has anyone managed a workaround for the rigid refrigerant(?) pipe in front of the pulley?

[sabino56]

On my 2006 E90 330i the metal AC line runs right across the pulley and it has to be removed to get pulley off. I read that some people with similar or same models have a different routing and pulley can be removed without evacuating the AC. I never spent the time to figure out differences in systems.

The pulley has a bearing which rides on nose of compressor and is always spinning. Compressor always spins also as it’s a variable compression compressor. When my bearing went out it started wobbling a bit and took out the compressor front seal. I went thru hassle of discharging, replacing bearing, and recharging before I realized the front seal was leaking. You may want to have some dye injected and check for leaks before replacing the pulley or bearing.
Good luck