Permit me a dumb question here - I just bought an 88 M3, seems to be a good car and the A/C was converted to 134 recently. On the way home from Memphis to Washington State, the air conditioner "pitched" it's belt and I see that the compressor is now not quite lined up right, as if one of 2 or more mounting bolts or bushings has broken or come loose. I can rock the compressor back and forth with my hand, I need to fix this before driving the car much. I have not had a chance to get under the car to check it out. I see that this system has an idler pulley to adjust tension on the belt - is this the stock setup or did the conversion to 134 include some sort of non-standard brackets?

I have a paper factory manual for the 89 year E30's and it does not show the accessories on the front of the motor.

I understand that the S14 is rough on accessories, are there any upgrades or tricks that I need to know about in fixing this?

I removed mine. You can fix it though... There are 4 rubber bushings that are essential to the operation of the bracketing system on your car. Idler pulley? Are you sure? I haven't seen that on any M3... You really need to get the car up where you can see what pieces are actually missing/ broken to further diagnose (it is probably missing hardware as well). Also, R134a is a terrible conversion, it draws more power and is less efficient. It just doesn't eat big holes in our precious ozone;)

You need to replace the rubberised bushings.
It won't hurt to run w/o belt.(engine feels more zippy). Check that all the mounting fasteners are present.
Also take a look at your alternator bushings, which will also show a gooey melted appearance when bad. they will allow misalignment of the pulleys and toss the belt also.
There are durable urethane replacements for the alternator bushings.
m.

Rip it out! I did :D You're in Washington and don't have to worry about the heat. I daily drive mine and I live in Texas!

Check the brackets, I've heard of them braking or cracking a lot. The bushings could also be bad.