At Hi RPM's on my 85, there is a very loud shreek-like sound coming from the motor area. Thought it was a belt, replace AC and alternator, no change.
What the heck is this?
Thanks!

 

sounds like bearings going out on something, had the problem with my zx, was the belt tension pulley, finally it siezed up and threw the belt off, get a two foot piece of garden hose and put one end to your ear and the other end to spots in the engine area,works like a stethascope, good luck,,,,,

 

have you removed the smog pump or any of the other pulleys lately , it sounds like the infamous "need a two groove alternator pulley" syndrome that a lot of us have

Check out http://racingbeat.com or
http://mazdatrix.com for a new one

 

I did take the air pump off long enough to wd-40 the bolts & threads (everthing has rust on it) but it did this before and after. Guess I'm gonna have to narrow down which device is squealing. What is the advantage of the two groove alternator pulley?

 

well if you have removed the pump or any of the other pulleys then the resistance of the belt in the groove has been reduced and the high rpm is causing the tiny belt to slip in its track , adding the double pulley adds resistance and reduces slipping

peace