wds928

Driving back from the Charlotte, NC Porsche Parade yesterday my normally very cold r134 A/C decided to go ambient on me.

Thoughts ranged from heater valve, refrigerant leak, etc. Just turned it off and drove home. Pulling into the neighborhood with both windows down, there seemed to be some screeching, squeeling noises coming from under the hood.

Thoughts really started going.....torque tube bearings, water pump (only 2-years old), a/c compressor, air pump.....

I ruled out the heater valve by testing it with the engine running and the A/C on and moving the temp slider from full cold to full hot and back. The vacuum changed moved the heater valve just fine.

Tonight after work, I sacrificed the a/c belt and viola, the screeching noise did not return when I started the motor. The a/c pulley turns freely, so I'm hoping the compressor did not eat itself and send shrapnel all through the system.

I've checked the usual sources and searched the archives. Also read Griffith's site. The Kuehl compressor, mounting bracket, new barrier hoses and dryer from them or 928Spec seems to be one way to go. The other is a rebuilt unit and a new dryer.

My system is factory r134 and when it was working (this past Sunday early afternoon to be exact), it blew ice cubes, or would keep beer cold. My car has 149,000 miles on it, so this could have been the original compressor or a rebuilt unit.

Any thoughts on staying with a rebuilt unit or changing to Kuehl? Anyone been there done that?

ROG100

Lot of success with changing out the compressor on GTS cars.
I only like the Porsche rebuilt unit at less than $500 plus a new dryer at $59.95 and an expansion valve $27.95.
Vacuum the system and replace what needs changing.
Roger

fst951

Your core is no good, so a rebuilt unit without a core charge isn't an option. However, if your clutch assembly is still good, I can get you are BRAND NEW FACTORY DENSO unit for about $500. Not so bad. I also have a rebuilt unit that I would put up against a denso rebuilt unit anyday for much less, but we need the cores. You will need to completely disassemble the system, replace A.C. o-rings and receiver drier, and expansion valve(s).

Tom in Austin

Unfortunately the screeching noise usually indicates metal shavings going through the lines, so as Roger says, it's critically important to change the exp valve and throughly vacuum the system to get all the junk out. Otherwise you get to do the compressor replacement multiple times.

Learned this the hard way on my wife's car years ago ... not a Porsche thankfully ...

dr bob

Flush the condenser and the line from the compressor to the condenser if there is ANY evidence of catatrophic compressor failure. If there's any grey dust in the compressor discharge or the line to the condenser, these are telltales of dirt/crud in the system. The Good News is that the drier usually blocks flow of the metal particles. A visual inspaection of the downstream plumbing is of course a must.

As you work on the system, no matter which path you choose for replacement, remember that cleanliness is absolutely mandatory. AC and auto trans hydraulics are two areas that suffer greatly with just the tineist bit of contamination.

BC

I really want to do the Kuehl, but there have to be other options that are just as good - and light.