1982 SD Turbo I5 Compressor Knocking
 

Hello,

Excuse me for not being up to speed on the search function here.

I have read that this has a R4 GM compressor but you need to get the correct R4 Compressor. Something about oil. This one is less than 2 years old and knocks and it won't turn by hand. I suspect it is on it's last leg?

Thanks