notaguru

My '83's AC has failed. It could be a pressure switch, a relay, the compressor, etc. but after 72k miles and 35 years I suspect it's just R12 leakage over time followed by the pressure switch working properly.
I've thought about an R134a conversion, and about simply repairing any leak and recharging with R12. These issues have been beaten to death on this forum, but for me this is the first time my car has needed such service. I'd like to find someone within reasonable distance who can advise and then perform - one way or the other.
Thanks!

GregBBRD

The selection of 928 mechanics in San Diego is virtually non existant. Many of those cars cone up to have me fix them, here in Orange County, and take the train home.

The Forgotten On

If you take the system apart yourself if you're feeling brave it is a must to replace all o-rings,
soft hoses,
expansion valve,
schrader valve seals (if not the entire thing when converting to r134),
and the compressor.

All these parts are prone to failure and wear at this point in your car's life.

What Greg is saying is very true, there aren't any 928 experienced mechanics in SD. You have to come up to LA county for that

griffiths

The 83 928 system is an alike any 80's AC system that has an expansion valve (you don't have rear air to worry about), other than the funky HVAC flap mechanisms and controls. Any reputable Porsche aftermarket repair facility that has all the equipment can service it (recovery station, evac, and charge, electronic leak detector).

Here is a helpful link to start you off in finding a Porsche Repair shop

https://www.pcarshops.com/

GregBBRD

I would certainly agree that this should be the case, but it certainly isn't. Almost any electically or vacuum issue in the 928 (extremely common) overwhelms the common Porsche service person. Add in a lack of experience to look at the places for common leaks and long term repair is very rare.

The vast majority of A/C repairs on the 928 model first require getting the heater to shut off when it should. It's amazing, but very few can even accomplish this!

griffiths

His has not been found to be the heater valve, or any other vacuum leak just yet.
Standard procedure is to see if the clutch is engaging, if not then check for power to the clutch, etc...
Toss on a set of gauges and move forward.
I've owned 3 sharks, from 78-89.

And, where he is now he could check the easy things.

We are not trying to level the suspension and do an alignment, just simple AC checks at this point.

Don't make mountains when there no mole hills.

GregBBRD

You know, all I can do is relate to people what I experience on a day to day basis....

I spend an amazing amount of time repairing 928 A/C systems that were "just repaired" a month or two prior.

For the people paying me to do this work the second or third time, I wish it wasn't true....but, unfortunately, it is

Speedtoys

Ya, are those the facilities with a Unicorn on display playing the harmonica that can list ver-batim the 928 specifics?

Note the URL and the high bar of qualifications to be listed on Pcarshops.Com

https://www.bimmershops.com/add

This is what costs classic porsche owners thousands of $$$ in bad work, and re-work seen on the forum on a monthly basis.

"Any reputable Porsche aftermarket repair facility"

It's like they're as common as any easy to find reputable Chevy aftermarket repair facility.

dr bob

Arguing about this in the abstract is pointless. It comes down to a specif tech at a specific shop who might be willing .and. able to diagnose and service the system. Griff proposes that the basic "diagnosis" of the refrigeration side of the system is hardly rocket science, and he's correct. The complications start when the tech discovers that there's something wrong, and he starts to apply basic troubleshooting to the symptoms he observes.

The subject car is a 1983 car, merely 35 years old and no indication from the OP about what "services" have been performed prior to now. We love our cars and believe that this stuff should last forever. But it doesn't. The 35+yo soft bits need to be REPLACED, simple as that. Rebuild or replace the hoses, replace the o-rings and the compressor seals. Replace the Schraeder valve seals, expansion valves, etc, put in a new drier and probably just a whole compressor. THEN check for remaining leaks after everything is reassembled and evacuated/recharged.

Sometime prior to finishing the refrigeration-side work, the air handling side needs to be functioning correctly. Will the tech at the generic import car repair place know what to do for this part? There's always a chance that there's a WSM handy and that the tech is experienced enough to leverage the WSM info with his own experience and make the right repairs to that side. There's no way to correctly diagnose the refrigeration side without the air handling side working correctly.

OP's task will be to find the tech in the San Diego shop. He asked here for a recommendation from others there, so he can shortcut the learning curve. So... Does anybody know a good 928-quailified shop and tech in the San Diego area? If so, can you share that info please?

OP -- your fallback is leaving the car with Greg Brown in Orange County. They will drop you at the train station in Fullerton for the ride back south, and pick you up there when the work is done so you can drive the car home. It's not as convenient as someplace a mile from the house, but it will get your AC working correctly the first time.

Randy V

Unless you have a AAA Membership.

BC

joejoe

Jeepers I am glad I have my own equipment.

GregBBRD

Be glad you not only have the equipment, but the knowledge to do this work.

In order to survive, most independent Porsche shops work on the late model vehicles, which mostly require the changing of parts...not much diagnostic or thinking required. Literally, anyone with basic tool skills can do this!

They are not interested in spending a couple of hours checking vacuum pods, heater control, A/C control unit, and then searching for tiny leaks in a 30 year old system. They want to blow some Freon into the system and get paid a couple of hours to "service" the A/C system, while spending 30 minutes.

Here, we do things differently. After all of the above items are inspected and repaired, we put pressure in the A/C system and let it sit for 24 hours....looking for a loss of pressure. We then pull a vacuum on the system and let it sit for another 24 hours to see if there are any losses in vacuum. It's amazing how many "little" leaks there can be in a 30 year old A/C system!

Huge difference in the end result. Tiny difference in the price....after all, there's not someone sitting there watching the gauges for 48 hours.

On Friday, we were down to 24 928's to work on. There's another 10-12 928 engines and transmissions waiting for me to do. Plus another pile of engines and transmissions (from other models) waiting patiently (sometimes impatiently) for me to "touch".

There's a reason....

My shop is the place people come, when other shops have failed to repair their 928. (The smart people come here, first, and pay once to get things fixed correctly, the first time.)

Yes, unless it is an emergency, it can take a month to even get "in the door" for us to look at a car...and some people aren't patient enough to wait. But I also know that 95% those "non-patient" people will call again....wanting to get on the waiting list, for us to fix what they just paid someone else to try and fix.

There really is a difference......