Author Topic: M42 compressor used anywhere else? (Read 3039 times)

ClayW · « **on:** June 02, 2011, 10:35:43 AM »

Is the AC compressor on the M42 used anywhere else? My motor didn't have one when I bought it and I am looking for one to get the AC project going in a few weeks.

colin86325 · « **Reply #1 on:** June 02, 2011, 11:29:27 AM »

Judging from bmwfans.info it appears it is unique to the E30 M42 cars.

DesktopDave · « **Reply #2 on:** June 02, 2011, 02:31:24 PM »

I'm not sure either. I'd figure the mounts are specific to the M42 definitely, but the compressors are somewhat interchangeable.

This annoys me - I should have checked when I had a few M20 units around. I just gave the last one away or I'd have a definite answer for you tonight.

monty23psk · « **Reply #3 on:** June 02, 2011, 03:50:46 PM »

I checked realoem for part numbers, and it is only e30 m42 specific for the r134a model. didnt check the r12 version.

DesktopDave · « **Reply #4 on:** June 02, 2011, 04:39:04 PM »

If you pick up an R12 version, just change out the oil. They're compatible with both refrigerants. I'm not sure which manufacturer is best, likely they're pretty much all the same.

You'll need an R134 expansion valve though, but I think that's shared with a lot of other cars, including BMWs.

If you figure this x-ref out, let me know. I have a BMW OEM r134 conversion kit (installed in my 325) that might find its way to my M42 if they can swap.

jakeb · « **Reply #5 on:** June 03, 2011, 07:26:03 PM »

The other option is to run an e36 m42 compressor and then get a serpentine belt pulley and swap out the vband pulley on the crank. You would need a e36 compressor, matching bracket w/tensioner, and then the matching compressor. I might even have some sitting around. I will have to take a look.

DesktopDave · « **Reply #6 on:** June 03, 2011, 09:33:34 PM »

That's an excellent idea. Should have though of it myself. Great time to upgrade the idler gear out of the timing chain too, eh?