I did a search and couldn't find another set of symptoms like this. We went on a ride with the Longhorn PCA group this weekend. From Laredo to San Antonio on the interstate, it was about 80 ambient and the a/c worked fine for 2 1/2 hours. Then the ride started and it was not spirited but with a lot of gear changes and the a/c stopped putting out cool air-not hot but just not cool in either recirculation or normal. Fan was working fine. We were really worried because the trip home was to be about 3 hours in 100-104 temps. But low and behold the a/c worked like a charm-or at least as well as an aircooled Porsche will do.

Any ideas on what may be happening. TIA

 

I'd guess that the evaporator froze over and either the freeze sensor shut down the compressor - which it is supposed to do - or it just froze enough to not let air over the coils.

 

A good friend wrote this DIY. This could be your problem.


http://ozarkpca.org/docs/injectors/2009_03.pdf

 

As BS911 mentioned, the evaporator froze over. You neglected to say if this has ever happened before and how long you have owned the car.

I had this same problem for the first four years I owned my car. Intermittent and only in very particular temp and humidity conditions. This is how the problem was solved.....

https://rennlist.com/forums/993-foru...cing-long.html

 

I have owned the car for about 6 years and this only happened once before. That was on the drive from Bangor to Laredo. The summer day in question was hot (Texas Hot!) and the leg was Little Rock to Laredo. Stop and go traffic in Austin and San Antonio. So after about 12 hours of driving the a/c gave out for the last 2. That was 2 years ago and the only time this happened. I was going to do the diagnosis then but it worked the next day and has ever since.

Thank you very much for the DIY-that is exactly what I needed.

Al