Automotive Air Conditioning Information Forum (Archives)

camaroman79 on Sat July 20, 2013 7:31 PM

Year: 1995
Make: camaro
Model: Z28
Engine Size: 350
Refrigerant Type: R134A
Ambient Temp: 95
Pressure Low: 45
Pressure High: 160
Country of Origin: United States

Hello I am trying to troubleshoot my z28 Camaro I have had problems with a slow leak from day one when I bought it. I just kept topping off.. then it degraded over the years to the point of 70 to 80 deg air out of the vents. and I have not been able to figure out why.
Then the ac clutch bearing started to howel so I replaced the compressor, drier and expansion valve and pulled a vac and replaces r134a. my pressures are low 40 high 165 on a 95 deg day. I did find that the condenser was caked up so I cleaned that and it made no difference. still blows 80 deg air and I am at a standstill. I did make a video to help explain my issue. so if anyone has any ideas please advise , and I did check the air mixing door. all I can get out of the system is a 15 to 20 degree degree drop in air from outside.

Here is the link to my video explaining in more detail. https://www.youtube.com/watch?v=xZaOBhz-p_c

Dougflas on Sun July 21, 2013 1:19 AM

you list high side as 160 and 165. Your video sayss 260. Which is correct? Condenser appears to be the problem as video states partly plugged with pebbles. Try an HVAC foaming coil cleaner. It will foam and push crap out of the condenser. Does your temp drop if you mist water on the condenser?

camaroman79 on Sun July 21, 2013 9:33 AM

camaroman79 on Sun July 21, 2013 9:37 AM

sorry I must have typed the number wronge. it was 260 PSI on the high not 160 . I did not try misting the condenser with water while running, I could try that

mk378 on Sun July 21, 2013 10:59 AM

Condenser fins munched up from road debris, you should just replace it.

Put the interior fan on low and rev the engine. Does that get the low side below 45? If not, there is a problem with the compressor.

camaroman79 on Sun July 21, 2013 11:35 AM

Ok today was a 85 degree day and I started the car let it run for 10 min put my probe in the vents it read 76 degrees, I hooked up a sprinkler to spray the condenser and it dropped to 62 degrees and then I shut the sprinkler off and it went back to 76 degrees. I have verified both my cooling fans are cycling when they need to. I don't get it I had that condenser cooled to the max and still could not get this a/c to cool . could there be a blockage in the condenser or maybe adding to many of those R134A cans over the years added to much oil to the system??? Any Ideas??

camaroman79 on Sun July 21, 2013 11:38 AM

I just replaced the compressor a couple of years ago, so before and after the compressor swap it made no difference on how well it cooled. My pressures look ok so I don't think its the compressor but im not an a/c expert, but I can do the work.

iceman2555 on Sun July 21, 2013 9:09 PM

There could be several issues at play. One is the statement about adding 'all those cans of refrigerant and too much lubricant'. This could be a serious problem, esp if the system was charged by pressures and not by weight. Pressures are not an indication of a fully charged system. If over the years the system was 'topped off' with cans of 134a that contained oil....good gosh there is no idea how much lube is in the system. Lube does not cool....it can become a serious insulator and restriction to refrigerant flow. Did you add lubricant to the system when the compressor was changed? If so, how much, what type and where was the lubricant added? Was the system flushed during the repair process? If so what type flush and what measures were taken to insure complete removal?

A good quick test for condenser operation. Start the vehicle and allow to operate for 5-7 minutes. During this time, continue to measure the condenser inlet temps by touching the line between the compressor and condenser. Should the condenser be restricted this line temp will continue to increase...to the point that you would not wish to touch it once again. Test the condenser outlet temp....if very close of ambient temp....the condenser needs to be replaced.

Air flow restrictions could be a problem....insure that the core is clean and free flowing....if not possible...replace the condenser. Be very careful when cleaning the core...do not expose fins to high volumes of high pressure water. This may damage fins....and require condenser replacement.

My first consideration would be the possibility of a undercharged system....esp if there is excessive lubricant is in the system.

First concern would be the possibility of excessive lubricant in the system. Determine is this is a possible issue and is so or unsure...open it up....flush it clean....drain the accumulator or replace....remove compressor and drain...add back 2-3 oz of lubricant back into suction side of compressor....add remainder of the system charge into the accumulator. Evac and recharge the system. Keep in mind that one must take into consideration the amount of lubricant necessary to precharge the hose/manifold hose assembly. Normally 3-4 oz. Add this to system charge...esp if not balancing the system after evaluations are complete.

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