Main Menu


Heating and Ventilation

Vehicle Information: Model: 964 Carerra 2; Year: 1991; Body Type: Coupe; Engine (type, size, modifications): 3.6; Total Mileage: 64200;

I am currently trouble shooting my A/C and need some help. I have replaced the expansion valve and the drier which did not help and have had a local Porsche shop make sure the charge was correct and also read the computer. They did not make it clear what the computer read but said it could be a sensor but they would need more time to look at it. This is not my daily driver and I prefer to figure this out if I can on my own but wanted to be sure the charge was correct. The problem is that I don't get cool air from the A/C. What the shop told me was that they know the evaporator is at 42 degrees but what is blowing out the vent is well over 80 maybe even hotter. I just ran the car for about 20 minutes and observed the compressor and all of the servos directing the air in the front trunk. Started the car and turned on the AC and the clutch kicked in and ran the compressor just fine. The condensor blower in the left front wheel well turned on after a few seconds and ran for the entire test. The compressor never stopped for the entire test unless I turned the AC switch off. It did not cycle even once that I saw(don't know if that is a problem or not). The high pressure line started to sweat and was consideralbly cooler than the return. Pressure line was in the 40 to 50 degree range (I am guessing by touch) and the return was well over 100, uncomfortable to touch. In the front trunk all of the servos responded to their signals. The two mixing chamber servos opened when I turned the temperature up and closed when I turned the temp down. I expected to see them start to open once the car heated up but they did not.The air may have been 80 degrees blowing from the vent but no cooler than that. I have read about a sensor repair kit in this tech section but I am trying to figure out what difference that will make unless it controls the clutch cycling and somehow that makes a difference. From the part number I have seen, 964-618-943-00, in this section the sensor they are referring to is the one at the evaporator and not the two mixing chamber sensors. Do you know what the sensor actually controls? Seems to me there should be cold air blowing from some where. Sorry for the lenghty note but wanted to give you as much info as possible.

You must log in to view answers associated with technical questions. Join PCA to participate in our community.
No votes yet