A/C warmer when standing still?

[anthonychacon80]

Anyone ever have a problem with the A/C blowing warmer air at idle than when moving? It is still "cool" but it turns much colder once I start moving again. Also, it takes a good 5 minutes to start blowing cold cold air. What temps should I be getting at the middle left vent? I checked my service manual and at 100 degrees outdoor temp I should be getting 50 degree at vent. Of course, it was 100 degrees this week in Chicago.

I checked my pressure level and it is at the top of the green zone (borderline Yellow "warning") on the gauge that came with the recharge kit. New Pressure cycle switch. I converted the system to r-134 when I rebuilt the engine, cleaned out the lines, new accumulator, evaporator core and lines. The compressor was a virgin and I put PAG 150 oil in it.

10 years ago, when the system was still r12 and I lived in California (inland area, 100 degrees sometimes) I do not remember the A/C being a problem.

 

[88hurstolds]

I'd think it would have something to do with the compressor operating at lower RPM's hence lower line pressure and less cooling. Also, the heat of the radiaor standing still can also affect the condensor and the engine heat itself standing still could increase the temps under the hood allowing for hotter air to be sucked into the cowl intake of the AC box...
It's a fairly common thing, my 2006 Chevy truck does it and I attribute it to the compressor not operating at high enough revs.

 

[anthonychacon80]

I am hoping it has more to do with the temp being 100 freaking degrees. It is like 70 today so I am going to see if it does better. WHen I redid my engine I put a clutch fan back on and yesterday my normally 195degree water temp went up to JUST below the Red Line on my rally pac gauge. Usually it sits just under the 220 at I think 195 which is my thermostat.

Would putting an electric fan on the radiator and a smaller one on the condenser help?

 

[outsider_27]

I noticed the same thing when I converted my 93 S-10 to R134.

 

[88hurstolds]

R134a isn't a good refrigerent if you dont have the system professionally cleaned out an properly oiled and new o rings installed.
Typically R134a will only give you a 20* drop in temperature so if it's 100* out youre gonna get 80* through the vents...

 

[86Olds442]

R134a isn't a good refrigerent if you dont have the system professionally cleaned out an properly oiled and new o rings installed.
Typically R134a will only give you a 20* drop in temperature so if it's 100* out youre gonna get 80* through the vents...

I got 45* coming out my vents yest, when it was 98* out. Granted I was doing 65 mph at the time. In stop and go, I miss my R12. It gets up to about 60*. I will probably switch back over to it in the near future.

 

[bill]

I am hoping it has more to do with the temp being 100 freaking degrees. It is like 70 today so I am going to see if it does better. WHen I redid my engine I put a clutch fan back on and yesterday my normally 195degree water temp went up to JUST below the Red Line on my rally pac gauge. Usually it sits just under the 220 at I think 195 which is my thermostat.

Would putting an electric fan on the radiator and a smaller one on the condenser help?

The more heat transfer, the more effective the system will be and thats why most modern cars have fans that come on when you turn the a/c on. The new synthetic ice freon is said to be a big improvement over standard 134a and supposedly saves gas..?
Also, these compressiors on our gbodys are barely able to produce the pressures needed for the size of the passenger compartments. Thats because GM was using smaller A/C Compressors in the late 70's/ early 80's to keep MPG's as high as possible and because of the space limitations. My 231 could barely get out of its own way when the a/c was running. I have heard of people using period correct Cadillac a/c systems in these cars and they work much better. Takes a bit of work, but if you live where its hot most of the time, its worth it!

 

[tc1959]

134-A is much less efficient,and runs at higher pressures,especially in a system designed for R12.
You will never get 50 deg air with it in a R-12 system .
You also should get a actual set of manifold gauges to check pressures,red ,yellow, green don't cut it.
You could have a problem on the high side and not know it.

 

[bill]

134-A is much less efficient,and runs at higher pressures,especially in a system designed for R12.
You will never get 50 deg air with it in a R-12 system .
You also should get a actual set of manifold gauges to check pressures,red ,yellow, green don't cut it.
You could have a problem on the high side and not know it.

So then the remedy for this would be to convert to a newer 134a compressor from an S-10 or something like that?

 

[trog]

heat transfer from the condenser = cooler vent temps. if your ac is cool while moving, you have an airflow problem, quick test, at idle(800rpm-right?) put thermometer in center vent, on med fan, run cool water (hose) over conddenser, if temp drops, you need more airflow at idle- a elect cond fan, set to run while the ac is on will also get you a quicker inital cool down.