Hi,

I have a question about the 996 A/C. It was in the mid 80's the last couple of days in Boston and I was in my '99 996. I bought the car in October and have never really used the A/C, but when I used it the other day, it seemed to be blowing almost hot air. In my X5, the A/C blows ice cold and right from when you turn on the car. It never even got kind of cold in the 996.

My guess is I need some more coolant or there is a leak, but I just wanted to check in with the experts. If I do need an A/C service, any places to suggest in the Boston area? Thanks.

 

I would say yes my A/C works wonderfully.

 

Measure the outlet temperature. It should be <55F.

 

Yah-- mine is pretty solid. As good or better than the ac in my (now ex) ML.

 

brrr... very cold. Good enough for Florida summer with a black car.
It took a full custom hose job, 3 desert grade condensers and new compressor to get my 87 3.2 cold. A major factor for me in upgrading to a 996.

 

My gets extremely cold, usually only have the fan on 1-3 bars on the hottest days in TX

 

my AC is good enough for me to put the top down when temp is 105 degree.

if i remember correctly, you are the first one comes to 996 board with AC problem.

996 's AC is as reliable as toyota, shall we say?

 

Should be, they use Denso compressors

 

A refreshing change compared to the nightmares I had with my 944's A/C. Cost me a fortune to finally buy a new compressor and upgrade to newer refrigerant. Booooo!

 

+1

 

May be time to do a recharge of the AC gas?

I know that Kragen type stores sell kits.

Anyone know if the 996 uses R-12 Equivalent, R-22 or R-134a?

Could also be leaking system or failing compressor of course, as you said.

 

A not proper working AC is actually a not too seldom issue in early 996. This is what my 996 buyers-guide says: "Air con faults. Earlier 996 can have leaks, most times from the condenser. If so you might find the car will not cool sufficiently or cool at all. A re-gas in this case will be a waste of time. After a few years air con systems can gradually loose their efficiency and require a re-gas, typically you get cool air, but not as cold as possible."

I actually had a leak in my 996 and had a broken AC O-ring in my BMW X3. Both got fixed pretty easy.

 

mine gets pretty cold.... if you don't use it, you WILL loose it........

 

Almost all modern day automatic climate control systems, including yours, use an internal airflow reheat/remix method so the airflow exiting the system is not so COLD as to be discomforting. There are two ways you might feel really COLD airflow from the system. One, if the cabin temperature is so high that it takes lots of cooling to quickly bring it down to your setpoint. And two, if you improve the system's overall efficiency dramatically by moving the setpoint to maximum cooling and then use LOW blower speeds. This latter method effectively bypasses the reheat/remix function.

In any case there is a design flaw in the Porsche 996 (& Boxster, cayenne, etc.) climate control system which I believe was carried over to the 997 series. Once the cabin temperature is very near or at your temperature setpoint the system will begin routing HUGE volumes of CHILLING airflow to the interior surface of the windshield via the defrost/defog/demist airflow ducts.

This is not only extremely wasteful of the system's cooling capacity it can lead to a VERY dangerous, HAZARDOUS situation.

Sudden windshield fogging....

On the exterior of the windshield.

My wife and I took factory delivery of our 2001 C4 and when we turned it back in I told the factory rep that something was amiss with the climate control as I had to keep "dithering"(***) with the setpoint in order to maintain our comfort level.

We picked it up on the east coast and were approaching Birmingham AL in the early evening on a HOT late June day and after just having driven through a rainstorm. I didn't immediately notice why it was getting harder and harder to see forward until I finally came to the realization that the windshield was fogging over on the outside.

We happened to also have a '99 996 at the time so when I got home I verified that it would do the same thing.

So if you want your Porsche climate control system to maintain your temperature setpoint more accurately and consistently ALWAYS manage the system air outflow manually. NEVER allow cooling airflow through the defrost/defog/demist ductwork.

VW had this very same problem with their version of the Cayenne but quickly addressed it via a firmware change.

Porsche not only denies it to be a problem they claimed, in writing, there is no comparison between the VW system and that in the Cayenne.

*** What I later determined was that once the system switched over to routing cooling airflow to the windshield much of the cooling capacity of the system was lost into the great beyond and I had to lower the system setpoint to compensate.

This can be avoided, obviously, by simply preventing the airflow from flowing out the defrost/demist/defog ducts.

 

OMG....another major flaw to add to the RMS, intermix, intermediate shaft.....and who only knows what's next. I'm going to go buy a Toyota....I've had it.