I have a 2004 Coupe that is cool at best but never cold. Had the charge checked. AC gauges were put on it and high and low side pressures are where they belong. One person told us that the coolant can lose its cooling properties over the years, should be replaced with new coolant, not reclaimed. Is this true? Or, is not very cold air typical of the C5's?

 

As long as you do not have the hot driver side cold passenger side syndrome or vice versa you most likely need to have a recharge done.

Should cost about 75

 

Mine getscolder when i use the auto mode.not sure why or if yours has that type of unit.just my 1cent

 

I have never heard of A/C refrigerant losing it's effectiveness. It can leak out but if it's all there it should work.

I would imagine your problems are more related to the HVAC unit not closing and opening the doors correctly to switch from heat to A/C.

You can try 're-indexing' the doors by pulling the HVAC fuses or disconnecting the battery for a few minutes. (be sure you have the radio code if you have security turned on)
When you re-connect the battery and start the car, you will hear the HVAC doors moving about for a minute or so.

Once that's done SLOWLY turn the temp **** all the way down to 60 degrees. It should start to blow air as cold as it can out both driver and passenger side vents. If this fixed it, then SLOWLY adjust the temp back to what you like (73?).

If this didn't do any good, then check the HVAC codes in the DIC (Driver Information Center) and post up the codes here. It may be more serious. The codes will tell us.

 

If it gets low from a small leak or seepage thru the hoses it won't cool properly. Mine was fully charged but did not cool properly. The $3 plastic orfice tube on the right front fender in the high pressure line was the culprit. Have to discharge to remove the tube (only 1 bolt holding the two parts of the high pressure line). Mine was stuck in there and I used some refrigerant oil and needle nose vise grip pliers to get the sucker out of the hoses. Might be what you need. A full charge is just about 2 cans of R134a.

 

Thank you all for your suggestions. Will look into these options.

 

What system do you have? The dual or manual?

 

Dual

 

R-134 is R-134... It does NOT degrade unless you somehow contaminate the system with air or moisture (usually happens when the system is OPENED for service and not properly vacuum purged out).


The contamination is called (Non Condensables) meaning that it won’t "Condense or Evaporate" in the system like the R-134 does and causes the system to become inefficient.

If you have NORMAL high side and low side system pressures, the Orifice Restrictor tube isn’t clogged. If you have low suction pressure and high discharge pressure, the orifice is clogged.

Read and post your DTCs. See if you have any damper door DTCs. That would be DIC B-0363, B0365, B0441, B0446. That would cause the temp damper doors to fail and not control the output temp properly. You MUST read the HVAC codes from the internal Code Reader. (not a scanner)

Set the driver’s side temp to 60 deg. Clear any HVAC DTCs from the DIC and the temp actuator doors should CYCLE to fully HOT to FULLY COLD and back to set temp. Do that procedure several times and see if you can get the HVAC DTCs to clear. If they will not clear, you will have to troubleshoot the actuators. They could be bad.


BC

 

Exactly right Bill!

 

Thanks guys. Sounds like a trip to a dealer. Have no equipment to do this fancy stuff. My husband and I work on older vehicles: our '66 chevelle for now. We have built many street rods and muscle cars previously. The 'vette was my retirement present in 2008. Merry Christmas and Happy New Year to all on this forum. (Sandy & Carl)

 

What is the hot driver side cold passenger side syndrome? My car does this sometimes. Somebody please elaborate.