Finally- cold AC
08-11-2012, 05:08 PM
#1
Three Wheelin'
Thread Starter
Finally- cold AC
Four years, two different Porsche indy shops, lots of $$$$, and Carlos at Jack's Gas Station in Cambridge finally has my AC blowing cold-
48-50 degrees out of the center vent, fan on 4, recirc on, top/bottom vents closed, 83 degrees ambient and 73% humidity on R134a, about 15 minutes driving at highway speed.
The problems were two:
1) The R12-R134a conversion fittings from Griffiths were leaking. I blame a ham-fisted installation and not the product itself. None of the indy mechanics caught this until I took off a plastic cap and saw that freon was bubbling out. I would give a charge and in a month's time there wasn't enough freon left for the pressure to be high enough for the compressor to kick on. New fittings and it looks like I finally have a leak-free system. I had it filled with dye previously and found nothing around the condensor or evaporator with a UV light.
2) Indy that replaced the fittings this week overcharged the freon. On the way home from the shop I could feel the compressor sporadically cycling on/off and the vent temps were barely below the ambient 80 degree temp.
Carlos evacuated the system and said there were 3lbs/48oz of freon in it and no PAG oil. He filled with 2lbs/32oz and oil and now it's cool as a cucumber in the cabin. Even still, I think that 32oz is a tad too much. R12 capacity is 35.8oz so the 80-85% rule for R134a conversion would put it at 29-30oz. Still a 35degree drop on a high humidity day and I'm plenty happy.
Hope that my misery can help any current/future sweaty 964 owners.
48-50 degrees out of the center vent, fan on 4, recirc on, top/bottom vents closed, 83 degrees ambient and 73% humidity on R134a, about 15 minutes driving at highway speed.
The problems were two:
1) The R12-R134a conversion fittings from Griffiths were leaking. I blame a ham-fisted installation and not the product itself. None of the indy mechanics caught this until I took off a plastic cap and saw that freon was bubbling out. I would give a charge and in a month's time there wasn't enough freon left for the pressure to be high enough for the compressor to kick on. New fittings and it looks like I finally have a leak-free system. I had it filled with dye previously and found nothing around the condensor or evaporator with a UV light.
2) Indy that replaced the fittings this week overcharged the freon. On the way home from the shop I could feel the compressor sporadically cycling on/off and the vent temps were barely below the ambient 80 degree temp.
Carlos evacuated the system and said there were 3lbs/48oz of freon in it and no PAG oil. He filled with 2lbs/32oz and oil and now it's cool as a cucumber in the cabin. Even still, I think that 32oz is a tad too much. R12 capacity is 35.8oz so the 80-85% rule for R134a conversion would put it at 29-30oz. Still a 35degree drop on a high humidity day and I'm plenty happy.
Hope that my misery can help any current/future sweaty 964 owners.
08-11-2012, 05:16 PM
#2
That's awesome! I hope one day to pay the big bucks to get mine up and running again. Mine may really need nothing, but I'm just too lazy and sort of afraid to look into it.
08-12-2012, 04:19 PM
#3
Three Wheelin'
Join Date: Jul 2007
Location: Helotes, TX
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I'm so jealeuous. I've had trouble with mine for 5 years. It finally quit a few weeks ago.
It's my daily driver and I had to (Granddaughter birthday) drive 5 hours in the 102 degree heat yesterday as my wife had the MB.
It's my daily driver and I had to (Granddaughter birthday) drive 5 hours in the 102 degree heat yesterday as my wife had the MB.
08-13-2012, 03:07 PM
#4
Rennlist Member
Took a trip over the mountains in Oregon this weekend. With 97 Deg and driving into the sun, it was having a hard time in higher altitudes... strangely enough it kicked back into full cooling at a lower altitude. The next day it was plenty cold on the way back. The sun was behind us so it helped, but I thought it was strange that it seemed altitude dependent on only one day.
