Airco compressor, does it matter which engine it comes from?

[NaweedMustafa]

Been a while from my end. To prep for summer, i need to swap out my airco compressor (makes a whining rattling sound when its switched on + doesnt cool the interior) however, i was wondering if there's a difference between the Calsonic compressor used in the pre-LCI M54 engine or LCI N52?

Found a breaker that has the airco from both engines, of course the one from the N52 looks a bit newer as it was pulled from a 2006 Z4.

Below are the pictures and part numbers for both.



Both compressors come from a 2.5L Z4




Secondly, would you recommend a new 3rd party compressor over a used one from a breaker? Definitely not considering a new one from BMW.

 

[fredej]

I'm not sure if they are interchangeable. To start with, is the dimensions of the pully the same?

I had to change my a/c compressor on my coupé (N52) and went with a used unit. Once installed, I could see there was a small leakage from the shaft seal.
So I ended up replacing it with a brand new unit from BMW. It got rather expensive.

 

[srhutch]

Real OEM will show you the compatible part numbers and if they have been superseded.

 

[enuff_zed]

Sorry, can't help any further with this, but I'd suspect the non-cooling may be due to a lack of refrigerant. Of course that could be leaking from within the compressor: and you'll need to replenish it after the swap anyway.

 

[NaweedMustafa]

Hmm, didn't logically think about the pulley dimensions, thanks!

@enuff_zed that was indeed my initial hunch, but as per the garage, the refrigerant wasn't too low (but was definitely on the low side), so that was topped up. A pressure test was performed and as per their investigation, no leaks. they only noticed the pressure of cooling (not sure what the real term is) was not high enough.

I may go for an aftermarket option as I am not too sure about the seals and lubrication levels on the used part. it is going for €70 so that is suspiciously low.

I normally go for OEM parts on the engine specifically but aftermarket airco pump should be alright i guess? its really just an additional accessory so i dont see it as a huge issue to save some costs there

 

[Dark Diggler]

Could it not just be the pulley that's goosed? It's a clutch pulley isnt it? so if the clutch has gone it will whine and the compressor won't work properly, I don't have any actual knowledge of this issue, it's just a thought!