E85 3.0i aircon compressor - Shared with?

[DaveP]

So, I'm on the hunt for a good used compressor (shout if you're breaking a car, obviously!) for a 2003 automatic 3.0i.

Ebay continues to be a frustrating place to search, particularly based on part numbers. RealOEM is showing me three different part numbers for the compressor here: https://www.realoem.com/bmw/enUS/showparts?id=BT52-EUR-06-2003-E85-BMW-Z4_30i&diagId=64_1273
- 64529158038
- 64506950789
- 64529182798

Firstly, any ideas which (or all?) of those is the correct one I should be looking for? (I'm going to try and look for a part # on the car shortly)

Secondly, searching on those part numbers brings up compressors for N52-engined E92s among other things. Do we know whether the Z4 shared a compressor with other models? (I had assumed the M54-engined E46, but it feels unlikely the N52 would be the same)

Thanks in advance!

 

[DaveP]

So it looks like I've found someone breaking a 2004 2.2, which appears to also be an M54 and crucially shares a part # with mine on RealOEM.

Anyone spot any issues with this?

 

[Pondrew]

Can't help with your part numbers, but interested as to what happened to your a/c compressor?
The actual compressors themselves are usually very reliable, as they are extremely simple mechanically.

 

[DaveP]

Can't help with your part numbers, but interested as to what happened to your a/c compressor?
The actual compressors themselves are usually very reliable, as they are extremely simple mechanically.

I don't think we'll know until it comes off, but it's not engaging at all in spite of there being pressure in the system.

 

[Pondrew]

I don't think we'll know until it comes off, but it's not engaging at all in spite of there being pressure in the system.

Sounds like the clutch or lack of power to the clutch. I presume the clutch assembly is not removable (a different part number) then?

 

[DaveP]

I don't think we'll know until it comes off, but it's not engaging at all in spite of there being pressure in the system.

Sounds like the clutch or lack of power to the clutch. I presume the clutch assembly is not removable (a different part number) then?

Doesn't look like it on RealOEM, sadly. The unit comes complete.

 

[Pondrew]

Not wanting to offend but I presume you definitely have power to the clutch magnet? It could be a dodgy low, or high, pressure switch if not.
In the olden days when I used to work on car a/c systems, I used to find a few where the electrical connections to the clutch had corroded or got damaged over time.

 

[Motionblurrr]

Not wanting to offend but I presume you definitely have power to the clutch magnet? It could be a dodgy low, or high, pressure switch if not.
In the olden days when I used to work on car a/c systems, I used to find a few where the electrical connections to the clutch had corroded or got damaged over time.

How can one check this?

 

[DaveP]

When I get a moment this week, I'll check the resistance of the low pressure switch and whether power is getting there.

It's pretty easy to access, being right next to the condenser.