Air con only works when running
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Racer
Joined: Dec 2004
Posts: 390
Likes: 47
From: CA & SP
Air con only works when running
Hi folks,
I am getting desperate about my two 911s. I own a 964 C4 Cab (40k miles) and a 993 C4 Cab (6k miles).
Both cars are giving me trouble with the air con!
When the car is running everything is fine and the car gets cool inside - I can feel the cool air going out from the dash grills. Meaning I have enough gas in it and no leaks!
As soon as I get stuck in traffic with the engine idling I fell that the cool and dry air gives space to a more humid and warm blow... pretty annoying on warm days driving at the rush hour!!
This is happening on both cars!!
How can I have this problem corrected? Is there a way to keep the air cool all the time? I would like to avoid taking both cars with the same problem to a dealer, and would rather do this service at home.
Any help would be highly appreciated!!
Cheers,
Freddy
http://www.356carrera.net/imagens/all-4.jpg
I am getting desperate about my two 911s. I own a 964 C4 Cab (40k miles) and a 993 C4 Cab (6k miles).
Both cars are giving me trouble with the air con!
When the car is running everything is fine and the car gets cool inside - I can feel the cool air going out from the dash grills. Meaning I have enough gas in it and no leaks!
As soon as I get stuck in traffic with the engine idling I fell that the cool and dry air gives space to a more humid and warm blow... pretty annoying on warm days driving at the rush hour!!
This is happening on both cars!!
How can I have this problem corrected? Is there a way to keep the air cool all the time? I would like to avoid taking both cars with the same problem to a dealer, and would rather do this service at home.
Any help would be highly appreciated!!
Cheers,
Freddy
http://www.356carrera.net/imagens/all-4.jpg
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From: Parafield Gardens
When you are stuck in traffic switch the fans speed to position 4 and press the recirculation button. This then provides cooler air back to the evaporator. Unfortunately this is a bit of a design problem not a system fault.
Ciao,
Adrian.
Ciao,
Adrian.
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From: Dana Point, CA
Sounds like your condenser fan isn't working. When the A/C is on, feel for air coming out of the grill at the left-front corner of the car. If you don't feel any, more than likely the ballast resistor for the fan has failed--very common.
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From: Atlanta
Try cleaning the AC condenser. Bugs, grit, and chaff (seeds grass clippings....) build up and obstruct the air flow. I built an L shaped tube to blow compressed air in the reverse of the normal air flow direction. I used a light and an inspection mirror to see what needed cleaning. I could see perhaps 50% light when I started, and 90% when finished. AC performance was much improved. Tip: run a vacuum cleaner on the back side, or you will will choke on the dust and dirt blown out by the compressed air.
Also check the condenser fan and the freon charge, and make sure the hot air flaps seal properly.
Don't be so certain your freon charge is correct. Good cooling at speed, and poor cooling at idle is a symptom of marginal freon charge. That is also a symptom of a warn compressor - unable to build up pressure at low RPM. A set of gages will show if that is the problem.
Regardless, you need something better than the standard 964 AC system to blow ice cold in slow traffic on a hot, humid sunny day. With the system in good condition, you can be comfortable on the hottest days, and nicely chilled on most days. I stay comfortable in Atlanta rush hour traffic with the fan on "3" and the recirc button pressed as Adrian suggests. My compressor was replaced in 2001, and has very few hours on it.
Also check the condenser fan and the freon charge, and make sure the hot air flaps seal properly.
Don't be so certain your freon charge is correct. Good cooling at speed, and poor cooling at idle is a symptom of marginal freon charge. That is also a symptom of a warn compressor - unable to build up pressure at low RPM. A set of gages will show if that is the problem.
Regardless, you need something better than the standard 964 AC system to blow ice cold in slow traffic on a hot, humid sunny day. With the system in good condition, you can be comfortable on the hottest days, and nicely chilled on most days. I stay comfortable in Atlanta rush hour traffic with the fan on "3" and the recirc button pressed as Adrian suggests. My compressor was replaced in 2001, and has very few hours on it.
