BigMikeATL

Not sure if my A/C needs freon or it is working properly.

When the temperature is around 80 degrees F, The A/C will just about freeze me out of the car. If the car sits in the sun and the temperature is above about 85 degrees, the A/C never really cools down.

Some have told me that the A/C in a 911 just isn't that great even when it's working 100%.

Thoughts, ideas, fish stories???

Rocket Rob

Is the 964 A/C system as strong as modern cars? No. Does it work? Yes. Can it cool the cabin? Yes. If you are having doubts, I would have someone check the system and make sure its at optimum working order.

My convertible's AC was getting weaker and weaker over the years. It was still running the R12. I had my mechanic check it and it was low on freon. He converted it to R134a and pulled a vacuum. It held well so he loaded it will the specified amount of R134a. The AC is working well again.

911wings

I have to top off my 134 each year mike, and i live about an hour south of you, 964 are not great in Georgia Heat

griffiths

You mean the ac in a 964 'cab' (not a 911 cab) ?

A 964/993 has no problems chillin at 85F with R134a, and at much higher ambients as well. Although cab's do absorb more energy than coupes or targas, they can chill.

Assuming when you get in the heatsoaker you;
1) Roll down the windows,
2) Start to drive,
3) Turn on the ac after the inside air temp is same a outside
4) Roll up the windows when you can feel cool air coming out the vents
Then, you chariot should chill.

The evap core temp gets pretty close to its coldest set point well within 10 minutes of driving. Most issues with this model are either low refrigerant charges or problems with heat or outside air mixing with the ac air (flap problems).

1990C2CAB

I've got a 1990 c2 cab, have had it out in ambient temps as high as 105 F this summer, & it cools just fine. I'd guess your refrigerant level is simply a little low.

SuperUser

Hey Mike, are you still running r12?

BigMikeATL

It was converted to R134.

tbennett017

Also the evaporator can get old and need replacement. I re-did my entire system last year. When I pulled the heater box apart the evaporator was 2/3 blocked with gunk. Slight leaks had created lubrication moisture that dust clung to, making it nearly all of it a solid brick- no airflow.

AB-Oz

I'd love to see a diagram of all the A/C parts, and their locations.

I had mine changed over to R134a a couple of years ago, it only worked for a couple of months after that. At that time the guy said a couple of the compressor blades were cracked. He then said that the compressor is the same used in a Toyota Camry of the same years, only the mounting plates are different - I don't know if this is true or not, I haven't pursued it.

I just put up with the heat in Summer :-(

FeralComprehension

You can download or buy the same program Porsche uses with all the diagrams and part numbers; it's not exactly easy but all the bits are there if you look.

springer3

Mike:

There is a sight glass on the receiver-dryer in the engine bay. Bubbles in the window indicate low freon.

BigMikeATL

I think that the R/D is in the front wheel well.

I'm going to take it to German Car Repair in Roswell, GA. They are Porsche enthusiests and have a good rep here on Rennlist. I called and they said $220 to pull a vacuum test and fill with R134. At least I'll know if I have a leak. How many 21 year old Porsches don't have a clogged up or leaking original evaporator?

I might get a price on a few other repair items that I was planning to perform. I may opt to have them done. But then again, it will also be justification for the wife to purchase a lift and do it myself for the same cost.

DWS964

When converting an R12 system to R134, which receiver/dryer should be used? I note that there is a different part number for the MY92 and earlier vs the MY93 and newer (which used R134). Should I order the later part for my 92, which came with R12 but has now been set up for R134? I will install new o-rings while I have things apart, too.

griffiths

Look at these:
http://www.griffiths.com/shop/index....th=15_16_56_58

-nick

Hey Mike- take your garden hose and pressure spray nozzle and blast the condenser through the louvers in the left lower bumper. You might be amazed at the leaves/detritus that comes out.

Also, an easy check for anyone is to remove the blue and red caps on the compressor schrader valves (on an r134a conversion). If you see any bubbling, then they're leaking. This was my issue that took a while to track down.

But if it will just about freeze you out of the car at 80, then it sounds like all is working. Black interior? A windshield sunshade could help dramatically.