Hello All, been fighting with a shop, that been doing work on my A/C for the 2000 Trans Am Ws6. I am biasing the how cold the unit is, off my 2001 Trans Am and 2001 Firebird.
February - Low Refrigerant .
Shop recharged the system and put a dye it, to detect a leak.
June - A/C Low again
Shop still did not see leak, recharged.
2 weeks later, low again. Shopped replaced the Compressor.
Early August - still not right
On the freeway, A/C works mostly well. In stop and go traffic I am sweeting in the care.
Shop replaced " A/C Low Voltage relay Switch". Sadly the Mechanic was gone, when I got there, and know one could show me, where that relay was located
Late August - Better not yet Right
On the Firebird V6 we have that Vacuum T-Valve that can go bad and mess-up the A/C
Does the V8 tie into the Vacuum system too?
Shop stated, A/C in Trans Am, does not rely on the Vacuum system.
I have noticed the P0420 is popping up over the last couple month, every time I come off the freeway, any possible relation?
I had fixed a long standing O2 Sensor problem on the 2001 Trans Am, that finally went away after replace the PCV Vacuum line "General Motors 12590632, PCV Valve"
Any chance this could be related to my A/C problem?

Much thanks to any help.

 

There's a vacuum source needed for the vents but has zero to do with the a/c functions or with the cold air. Replacing the compressor, dryer, orifice tube and all of the seals and pulling a vacuum to check for leaks and if none present then charging the system with the required amount of refrigerant is standard procedure. It's that simple!

Surprisingly, I am still running around with the same compressor and dryer but I did replace all the o-rings on the compresser control valve, all the seals for the lines as well as the schrader valves and the orifice tube in the line. If you're losing refigerant then its obvious that there's a leak somewhere and it could be in any of those areas as well as the condensor, evaporator core, dryer or something as simple as a leaking schrader valve. My advice is to buy the tools and do the job yourself or find another shop.

 

Thank you for the information. A/C and Transmission rebuilds, are the 2 things in my life I never learned. Maybe its time.....

 

^ Exactly that.

None of the other concerns listed in the first post matter in this regard; it has nothing to do with O2 sensors, vacuum lines, catalyst efficiency codes, etc. Only a hard leak can cause refrigerant to disappear, and until the leak is found this problem will continue.

 

Yes, your V8 uses vacuum for the HVAC system. The shop is wrong. The vacuum actuator controls the blend door for temperature. A leak could definitely cause your issues. The P0420 code (catalyst efficiency) is likely a separate exhaust issue, but a vacuum leak from a broken line could cause both the code and your AC blend door to not work properly. Check all your vacuum lines, especially the one going to the HVAC controls behind the dash.

 

A vacuum leak will not cause the AC system to be low on Freon, and the OP mentioned that the shop was unable to find the source of said Freon leak. Replacing the compressor was just a shot in the dark since they weren't able to confirm the source (and, unfortunately, the aftermarket compressors that are now the only option for this application don't seem to work as well as the originals - would be a shame to have dumped your original if it wasn't the leak source). Blend door actuation is irrelevant if the system cannot maintain proper Freon level.

Check to make sure Freon level hasn't dropped yet again before worrying about anything else. Low Freon will definitely cause the system to work poorly at idle/low rpm.

 

If this is the case, check your A/C Condenser. It's strapped to the front of your radiator and looks like a second radiator. You might have a dead bird or squirrel mooshed inside it.

If your condenser is clear, then the next thing I would check are the fans that pull air through the condenser and the radiator.

If everything works well when the car is moving but not when its idle, then this is the area where the problem likely lies. ^