2002 Yukon Air warms up at idle

[WarWagon]

Missing something here.

First try: Low side high around 60 PSI and high side low around 150. - Replaced compressor, accumulator, OT, and added the 4S Deslugger. OT was spotless. Did not do TXV in rear. 1st design with old style OT and rear line going direct to compressor inlet.

Same issue - Cleaned condenser and modded fan clutch - little too much as fan won't shut off now. Evac and recharge a 2nd time with scale recovery machine and amount recovered was bang on. 2.7 Lbs.

High side will climb now with new compressor to 200 -250. Cools great while moving or idle under 95 degrees outside. Warms up at idle over 95 degrees out.

There is a TSB calling for adding an electric Condenser fan for some vehicles with the 6.0L engine, but, it didn't have this issue before. It has the 5.3 engine. Document ID # 824198 GM P/N 15717423 Fan Asm - Aux Eng. Cool.

I am thinking the TXV is stuck open. Otherwise I am out of ideas.

 

[Diesel Nut]

Is the OT bad? The OT is a metering device. I've seen this happen before. The standard that remember from school was 20 or 30 degrees below ambient temp. Also check your charge. I believe that the suburbans where 3lbs with rear AC.

 

[WarWagon]

In depth AC repair guide
http://www.4s.com/upload/Four Seasons/Documents/Air Conditioning Diagnosis Service and Repair V2.pdf

 

[THEFERMANATOR]

Start feeling your liquid lines, and see where your getting warm at.

 

[WarWagon]

Nothing wrong with the AC system. Just not enough engine, compressor, and fan RPM for 110 degrees out. Went over it with a fine tooth comb. Even alternate refrigerant didn't help. No room for an electric condenser fan and the fan clutch mod had the fan at 100% lockup anyway.

So we fix GM's engineering and bean counter compromise likely due to CAFE. 550 RPM ARE YOU FING KIDDING ME?! Enter HPTuners:



May fine tune this some if the RPM drop between gears or P/N drops the clutch from triggering the anti stall code.

 

[WarWagon]

Didn't like 750 RPM in gear as it would vibrate with a harmonic. So set it to 700 RPM. Shifting into gear does kick the AC clutch out with the "stall saver" seeing a 200+ RPM drop on the 1st shift. Shifting again doesn't trigger it or drop as much RPM.

106 degrees F out and COLD air at idle... Finally!!! Long hot summer with lots of over 100 degree days out here.