jtischner

I posted this a few months ago, but can't find the thread.

I have a consistent problem. I've changed the a/c compressor 4 times. I've also changed all the associated parts including the head unit. When the car is under normal load (low rpms), the a/c works just fine. But when th engine is under heavy load, the a/c compressor siezes and burns out the clutch. I have a new compressor but need guidance on what could be causing the compressor to seize under heavy engine load (high rpms).

Thanks.

Joe

Imo000

Is there enough voltage going into the clutch?

Tampa 928s

Have you put gauges on it checking for high head pressure at higher rpm?
Blocked expansion valve could be a cause.
You replaced the compressor 4-times and what associated parts.

dprantl

When a compressor seizes, the lines, evaporator(s) and condenser must be flushed thoroughly. The expansion valve(s) should also be changed, as well as the receiver/drier. When installing the new compressor, the correct amount of oil needs to be put back in taking into account the flushing of all the components.

Dan
'91 928GT S/C 475hp/460lb.ft

jtischner

Thanks for the thread and suggestions. I did change the receiver/drier, expansion valves and completely flushed the a/c system. The system works fine, a/c blows cold air, turns on and off properly, all under low engine load. It's only when the engine is under heavier load (higher rpms) that the clutch/compressor burns out. Now I'm not completely sure about the high head pressure at higher rpms or if there is enough voltage going to the clutch.

griffiths

J,

Here is your previous post:
Compressor Problems

If you can answer these questions :

1) Is this a single evaporator system or dual air (has a rear evaporator between the back seats) ?

2) What type of refrigerant and how many ounces did you put in the system?

3) What type of refrigerant oil and how many ounces did you put in the system?

Regards,
Kuehl