A/C help 89 G50 911

[alexmaxfield]

Hello My 89 911 Has high pressor at 350 and does not come down to the same a the low pressor.
high at 350 and low at 100 with 1.7 134 R coolent.
Anyone have a cure for this or what rto do to fix it?
Thanks Alex

[speeder]

Yes, bring it to someone who knows how to service A/C systems. You have a major blockage, hopefully an expansion valve. If you’re the unlucky type, it’s the evaporator.

[Zeke]

What's the history here? Is it blowing cold? Someone playing around and overcharged? Unless you can provide some more info, follow speeder's advice.

[stevej37]

Maybe post this in the 'Technical Forum' also.
Prob get better response there.

[Bob Kontak]

Originally Posted by speeder

Yes, bring it to someone who knows how to service A/C systems. You have a major blockage, hopefully an expansion valve. If you’re the unlucky type, it’s the evaporator.

+1 on expansion valve. I have seen 425psi on an 89 and that was the problem.

[Chocaholic]

AC help, 89 911. Chuckle.

Save your money. That says it all.

[GH85Carrera]

G body 911s can have fantastic AC. Mine does. But you need some parts from Griffith’s.

Any you need some professional help.

[KFC911]

I usually don't use A/C in any of my vehicles ... but the one on my '88 was actually pretty good the couple of times I did. It's been boxed up in the garage for many years now tho'.


My "priorities" (see other thread) have never changed

[mattdavis11]

That system has a 10P15C compressor. You should not have an issue there. Condenser fan, maybe expansion too. Run some water over the condenser then tell me the drop.

[fintstone]

Originally Posted by GH85Carrera

G body 911s can have fantastic AC. Mine does. But you need some parts from Griffith’s.

Any you need some professional help.

I agree. I have an '89...and even when at its stock best (with R12 and serviced by an "expert" on these cars), it could not significantly cool the car on a warm day.

I had a '74 with a more modern system (including extra condensers) that had about 20 degree cooler bent temps.

[Nick Triesch]

When I went through my AC on my 85, I had a blockage. Turned out to be the expansion valve. My system works. Especially on a cool morning!!! 45 degrees on a cool day, 60 degrees on a warm day. The good news is expansion valves are cheap and easy to replace.

[stevej37]

no answer from the OP.

[fintstone]

Originally Posted by Nick Triesch

When I went through my AC on my 85, I had a blockage. Turned out to be the expansion valve. My system works. Especially on a cool morning!!! 45 degrees on a cool day, 60 degrees on a warm day. The good news is expansion valves are cheap and easy to replace.

60 degree vent temps would be considered not working for most AC systems.

[fintstone]

This is what I want to do to my Carrera:
Obligatory 32F AC vent image

[GH85Carrera]

Originally Posted by fintstone

60 degree vent temps would be considered not working for most AC systems.

That is only worthwhile at night, on a muggy day.

My AC system was pure stock and tuned up perfectly. If the outside temp was above 90 on a full sunny day is was pretty useless. Before driving out through a lot of hot states on my way to California in 2007, I contacted Charlie Griffith at his business and took his advice and invested in two additional condensers, new evaporator, all new hoses, and extra vents for my 85 911.

I have done pretty much every project and upgrade possible to my 911, and with no reservation the single BEST upgrade of them all, is to the AC system. I can comfortably drive my 911 in the very hottest places and my wife will go with me and we ride in comfort.

When she gets cold in Savannah, Ga, in August during a lunch time drive and asks me to turn the temp UP I know my AC kicks butt on the heat. Key West in July is great for fogging up sunglasses, cooled by good AC of my 911, when stepping out of the car.

[fintstone]

A decade ago when I bought my low mileage, pristine '89, I got the stock AC checked out and spent a bunch on R12. The very experienced tech proclaimed success...that it worked perfectly and was one of the best he had seen. I was ecstatic. He went on to excitedly tell me that he was able to get the vent temp under 60 (in the 50s). Remembering the mid 30s vent temps in my '74 (with a system as in the post above) and noting that we were inside his cool shop...I was underwhelmed, but thought to myself...better than nothing. I drove the car out into the heat of the day and felt the vent air turn warm almost instantly. Oh well...should have known. Might have been good enough for Germany...but not Vegas.

[KFC911]

I've always parked my '88 inside ... never letting it get "hot" to begin with for my drives. No way the stock system will cool down one in extremes.

As a youngin' I moved to FL with a new Subaru (no A/C on it) where it baked in the sun all day .... that wasn't pleasant at 4 in the afternoon, so then I went to play b-ball outside to cool off .

After a couple of years, I bought a brand new '87 Supra Turbo .... I thought the A/C was very meodicre too, but that was "back in the daze of ties" so I used it .

Returning to NC with that car where I was then parking it inside during the day was a whole 'nuther experience.

No A/C works well in Hell's heat unless ya pay the devil !

I'm very heat tolerant tho....

[GH85Carrera]

Originally Posted by fintstone

A decade ago when I bought my low mileage, pristine '89, I got the stock AC checked out and spent a bunch on R12. The very experienced tech proclaimed success...that it worked perfectly and was one of the best he had seen. I was ecstatic. He went on to excitedly tell me that he was able to get the vent temp under 60 (in the 50s). Remembering the mid 30s vent temps in my '74 (with a system as in the post above) and noting that we were inside his cool shop...I was underwhelmed, but thought to myself...better than nothing. I drove the car out into the heat of the day and felt the vent air turn warm almost instantly. Oh well...should have known. Might have been good enough for Germany...but not Vegas.

Back in 1983 War Bonnet Region PCA held Tech sessions, and we always got support from the factory. In 1983 Peter Schutz the big boss of Porsche AG as I remember, wanted to take a vacation and drive down Rt-66 to California from Oklahoma City. He had the factory deliver him a brand new 911 SC and after Tech was done, he set off to California down Rt-66. When he returned he called the engineers responsible for the AC system into his office. He said he had a project for them. He sent them to Oklahoma and said drive west on R-66 and when you get back report back to me. They were thrilled of course. Then they reported back to the boss. They said, sir the AC system in the 911 really is quite poor. And Peter said, yes it is, fix that!

It was too late for the Carrera and all they managed to do was improve the vent sizes by 1986 and change the fan housing. It was not until the 964 that the AC became adequate.

[masraum]

Originally Posted by fintstone

A decade ago when I bought my low mileage, pristine '89, I got the stock AC checked out and spent a bunch on R12. The very experienced tech proclaimed success...that it worked perfectly and was one of the best he had seen. I was ecstatic. He went on to excitedly tell me that he was able to get the vent temp under 60 (in the 50s). Remembering the mid 30s vent temps in my '74 (with a system as in the post above) and noting that we were inside his cool shop...I was underwhelmed, but thought to myself...better than nothing. I drove the car out into the heat of the day and felt the vent air turn warm almost instantly. Oh well...should have known. Might have been good enough for Germany...but not Vegas.

I had a stock '88 targa (no aftermarket tint). It blew cold in the summer in Texas. There was something wrong with that system or the guy didn't know what he was doing.

[masraum]

Originally Posted by GH85Carrera

Back in 1983 War Bonnet Region PCA held Tech sessions, and we always got support from the factory. In 1983 Peter Schutz the big boss of Porsche AG as I remember, wanted to take a vacation and drive down Rt-66 to California from Oklahoma City. He had the factory deliver him a brand new 911 SC and after Tech was done, he set off to California down Rt-66. When he returned he called the engineers responsible for the AC system into his office. He said he had a project for them. He sent them to Oklahoma and said drive west on R-66 and when you get back report back to me. They were thrilled of course. Then they reported back to the boss. They said, sir the AC system in the 911 really is quite poor. And Peter said, yes it is, fix that!

It was too late for the Carrera and all they managed to do was improve the vent sizes by 1986 and change the fan housing. It was not until the 964 that the AC became adequate.

That's a cool story that I hadn't previously heard.