Original '86 944 garage find

[355]

So now that the injectors were cleaned and working properly along with the fuel rail being rust free I reassembled everything and turned the key once again. The engine started almost immediately and idled perfectly! It didn't make any smoke from the tailpipe nor make any bad sounds other than the collapsed lifters clacking away. After it had run for a few minutes I decided to try the clutch and brakes and they both worked great so I tentatively tried a drive through my subdivision after grabbing a fire extinguisher. The ancient tires were so flat spotted and not round that the car shook like crazy at anything over 20 mph but it didn't overheat and the more I drove it the better it ran. After about ten minutes the lifters quieted down and it ran better but everything was very stiff from having sat for so long. I returned home, parked it back on my lift and checked it over. Other than the hot, moldy smell coming off the engine and exhaust there wasn't anything bad going on. There weren't any coolant or oil leaks, no smoke from the exhaust, no overheating, the brakes and clutch worked well and it didn't catch on fire so I was extremely pleased. All that work paid off and I now had a running and driving 944!

The only problems left were the power windows, mirrors, HVAC interior blower, reverse lights and the A/C that didn't work. That the windows didn't work was the reason this car was parked so many years ago by the upset prior owner and the fix for all of the electrical problems turned out to be an easily replaced part that cost less than $10 and supposedly had been repaired by the Porsche dealer for $2,500 a week before the windows failed to work again for the prior owner. If only he knew what I did to fix the problem he would have been even more upset!

[Tom]

Great read, and great work! I wonder how many old barn finds were moth-balled for trivial reasons like that -- I'm guessing quite a few. People get few up and just let it sit (and sit and sit).

[355]

Great read, and great work! I wonder how many old barn finds were moth-balled for trivial reasons like that -- I'm guessing quite a few. People get few up and just let it sit (and sit and sit).

I am sure you are correct that most barn finds are the result of the owner just giving up on a car that has had something go wrong with it and then it just sits abandoned until someone discovers it. Of course, for the guy that finds it, it is usually trying to figure out what happened to cause the car to be abandoned in the first place that is the risk when taking on the project of bringing the car back to life. It could have been something relatively simple to repair or a major mechanical failure and then there are all the other systems in the car that now have problems from sitting over time. It always surprises me that guys these days will pay a premium for a barn find car when they have no idea what went wrong with the car and what it is going to take to bring the car back. It's never a matter of just changing the fluids, installing a new battery, pouring in some fuel and turning the key.

[355]

So now with the car running and driving and having only changed the engine oil I went through the car and changed all the fluids. Amazingly all of them were original but clean including most of the brake fluid. Only the clutch slave cylinder had dark fluid in it. Even the coolant looked and smelled new and there was no silt or corrosion in any of the water passages in the engine or radiator that I exposed during flushing and refilling the system. With fresh fluids the transmission and power steering worked better and smoother and the car continues to run and drive better the more I drive it.

The next thing was to figure out what had caused the power windows to stop working which had led the prior owner to stop driving the car. He had taken the car to the local Porsche dealer to have the windows repaired and they returned the repaired car to him a couple days later. Soon after that the windows failed again and that's when the prior owner parked the car in the garage and never drove it again. I never did figure out what the dealer had done to repair the windows other than there were two power window relays in the car. A newer dated one was in the relay socket and the original one was in the glovebox so it appears they changed the relay but the bill was for $2,500 so they had to have done other things too. Upon further examination I found that it wasn't only the windows that no longer worked but also the mirrors, interior HVAC blower and reverse lights. By pulling the various relays and bypassing them I was able to make these items work again but then they were powered on all the time. At least it showed the circuits were good, but they were not getting power when the ignition switch was on. Things were starting to point towards a bad ignition switch but I did some searching online and found others that had a 944 with the exact same dead circuits. I finally found a post on the fix and it turned out to be a simple high amperage relay known as Relay X. I found the relay, pulled it and bypassed it with a jumper lead and all the dead circuits came to life. It turns out that most of these circuits have separate relays that get their power from the main power supplied to the fuse box by Relay X and when Relay X fails none of the individual relays have any power so the circuits go dead. I found Relay X is a common A/C clutch relay on may other cars and can be purchased for under $10. I swapped in a new relay and all the circuits came back to life when I switched on the ignition. That this car was abandoned over an easily replaced relay is hard to believe but that is what happened.

[355]

So now I am faced with the last problem and that is the A/C is not working. The good news is the system still had refrigerant in it and the compressor still ran when the A/C was switched on. The bad news is the system was improperly converted to 134a years ago when the original refrigerant oil was not drained and flushed out so severe internal corrosion of all the metal parts resulted.

With my gauges hooked up I was seeing negative pressure on the low side and too high a pressure on the high side indicating an obstruction in the system. I reclaimed the refrigerant and removed the receiver/drier to find rust particles in it. Then I removed the expansion valve and found it plugged with rust so I figured that was causing the no flow condition with the refrigerant. I then disconnected all the hoses and pipes from the condenser, compressor and evaporator and flushed everything out with pressurized A/C system cleaner and compressed air until there were no particulates coming out of them. The only part I didn’t flush was the compressor because that would most likely damage it. Everything was flowing compressed air well so I buttoned up the system after installing a new expansion valve and receiver/drier, evacuated the system and recharged it with some R12 I still own from my old cars. This resulted in the exact same problem with the pressures so I hadn’t found the obstruction.

After recovering the refrigerant I decided to remove the condenser to test it again but this time off the car and it seemed compressed air did not flow through it as well as I remembered so I swapped in a brand new one and evacuated and recharged the system again only to have the exact same pressure problems. The low side is still showing a vacuum with the compressor running and the high side is over pressurized. The only thing in the system left that could be plugged now is the evaporator and replacing that would mean removing the dashboard and HVAC box to get at it. Seeing as the dash is in perfect original condition I am not willing to remove it and break a bunch of old plastic parts in the process.

So my question, and the main reason I joined this forum, is whether the evaporator can be replaced without taking out the dash and HVAC box or not. If the only way to accomplish this is to remove the dash, is there a way to successfully flush the evaporator with it still in the car? The hot and humid Georgia summer weather is already knocking on the door here so I am really in a quandary now with this project.

[Tom]

On the oval dash cars, I believe the dash needs to come out to replace the evaporator, unfortunately. We have a comprehensive guide for that here:

viewtopic.php?f=19&t=341

It's not as bad as you might imagine. However, I wouldn't do that unless/until you are absolutely sure the evaporator is plugged and after you've tried everything to clear it out. I used A/C Pro Power Clean and Flush (big aerosol cans) when I updated my A/C, as recommended by Griffiths.

See the diagram below. If you get the hoses off the evaporator, you can check it for obstructions and go to town with the flushing agent. I'd also quadruple check all the other components in the system to make sure they are all working. While a blocked evaporator is logically possible, I can't say I've ever heard or seen that happening on a 944. (Although your car is unique, so future performance may not equal past results....)

You can also use an infrared temp gun to follow the heat on the high pressure side, and see if you can pinpoint where it suddenly goes cold (after the block).

acsystem.jpg (545.87 KiB) Viewed 1442 times

[355]

Yes, I have studied your dash removal instructions and they are really great and I agree that removing the dash would be a last resort with this car. I flushed the evaporator extensively the first time I tried to repair the system with the A/C Pro Flush product and it seemed to flow through it well when I had everything apart so I didn't test it any further. The only thing that I didn't do was remove the hard line attached at the firewall from the evaporator because the access is so poor but instead flushed it from the expansion valve fitting after I removed the original valve and found it clogged with rust particles. I removed the flexible hose at the other end of the line at the compressor and put the end of it in a plastic bottle to collect the flushing fluid and debris. Not a lot of debris came out and when I purged the flushing fluid with compressed air it shot out quickly with good air flow. Maybe I need to remove that hard line at the evaporator and flush the evaporator from that direction too. Of course having to remove and refit the blower assembly and upper case from the cowl each time to gain access to the evaporator fittings is not much fun and the A/C fittings at the evaporator are getting quite the work out now that they are on their third time being disassembled and manipulated but it is the only thing left to try as far as I can tell. I can also check the new expansion valve to see if it has already gotten plugged too which could be possible if I was not successful at getting all the debris out of the system. This has turned out to be the most frustrating and difficult part of bringing this car back to life and should have been a relatively easy job.

[355]

After many months of struggle, the A/C is finally working again on this 944 and it didn't involve removing the dash. After disconnecting all the refrigerant lines and hoses, running A/C cleaner through everything and verifying everything flowed properly I determined there was no blockage in the system. The only component left in question was the compressor which appeared to be working correctly but it turned out there was something wrong with the valving in it that was not allowing the refrigerant to flow out of it. I installed a new compressor, evacuated and charged the system and it's blowing 45 degree air out of the vents now.

On another note, this will also also be my last post on this 944 because it has been sold to another Porsche enthusiast. Hopefully he will join this forum and continue updating this thread.

[stitch2k1]

After many months of struggle, the A/C is finally working again on this 944 and it didn't involve removing the dash. After disconnecting all the refrigerant lines and hoses, running A/C cleaner through everything and verifying everything flowed properly I determined there was no blockage in the system. The only component left in question was the compressor which appeared to be working correctly but it turned out there was something wrong with the valving in it that was not allowing the refrigerant to flow out of it. I installed a new compressor, evacuated and charged the system and it's blowing 45 degree air out of the vents now.

On another note, this will also also be my last post on this 944 because it has been sold to another Porsche enthusiast. Hopefully he will join this forum and continue updating this thread.

What AC flush stuff did you use. I need to flush the S2 badly. I need AC

[355]

The product I used was the same one that Tom recommended and can be purchased at most auto parts stores. It is A/C Pro Flush and comes in an aerosol can with a hose attached with a rubber fitting on the end that seals to the ends of all your disconnected A/C components.

B2089044-9893-429A-B84B-1516FEAADA45.jpeg (213.57 KiB) Viewed 1028 times