Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

Little cooling at idle

mxz583 on Sat June 20, 2009 7:12 PM User is offline

Year: 1997
Make: Chevy
Model: G1500 Express
Engine Size: 5.7
Refrigerant Type: 134a
Ambient Temp: 90
Pressure Low: 55
Pressure High: 200
Country of Origin: United States

there is some cooling at idle but not great at 1500 rpm it gets better but not much low side is 55 and high is 200 at 1500 low is at 50 and high is 275 i replaced the compressor this past fall, ever since then cooling has been on the poor side at best. I think I have a bum compressor, but the guy I bought it from does not think so.


Thanks


Cussboy on Sat June 20, 2009 8:11 PM User is offline

For help, post answers to all questions.

(1) Is the cooling substantially better when you are driving on the highway at like 55 mph? If so, it sure sounds like you need a new fan clutch for your truck, not getting enough air flow over condenser at low speeds/idle.

(2) If answer to (1) is "NO", how much R134a did you add after you replaced the compressor? When you replaced the compressor, you did pull a good vacuum vacuum with a vacuum pump, didn't you? I ask because both high and low pressures seem a little high, but that can relate to question 1.


Edited: Sun June 21, 2009 at 2:56 AM by Cussboy

mxz583 on Sat June 20, 2009 8:19 PM User is offline

cooling is better at 55, yes i pull a good vacuum with a pump put in 5.25 pounds 134a

Cussboy on Sun June 21, 2009 2:59 AM User is offline

Read pressures again while spraying the condenser with water from a hose, should go lower, should help cooling. Sounds like you could be needing new fan clutch. At 55 you have increased the air flow over the condenser, need the fan do do a better job of this, hence fan clutch.

mxz583 on Sun June 21, 2009 9:16 AM User is offline

what about the orfice tube, could that be clog?

Cussboy on Sun June 21, 2009 10:33 AM User is offline

Quote
Originally posted by: mxz583
what about the orfice tube, could that be clog?

I think if that happens, your low pressures will be substantially lower, because little refrigerant would be getting through, but let a real expert comment/post. To check that you'd have to first recover your refrigerant, then open up to check.

Hint: I'd sure try cooling off the condenser with a water spray first.

mxz583 on Sun June 21, 2009 12:53 PM User is offline

ok i sprayed the condenser with water it did not do much drop low side by 5 lb high side maybe 20 lb. Pressures before i sprayed with water was low side 45 high side 145 at idle at 1500 rpm it was 35 low 160 high. vent temp is at 60 outside is 88. my old compressor had vent temps at high 30's low 40's before it lock up i did change the orfice tube and the dryer when i put in the new compressor

bohica2xo on Sun June 21, 2009 5:28 PM User is offline

Does this G van have rear A/C?

You said the compressor locked up. How much trash was in the orifice tube?

If the compressor spit out a lot of debris, that condensor is a doorstop. Those have tiny passages, and are very difficult to flush.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

mxz583 on Sun June 21, 2009 11:00 PM User is offline

orfice tube had some alum. on the screen i did flush the system everything seem to be open . if the condenser was clog up then would my high side be high ? and yes i have rear A/C and that is not cooling very well

chillin on Mon June 22, 2009 4:50 PM User is offlineView users profile

Were the rear lines and evaporator flushed?

mxz583 on Mon June 22, 2009 6:39 PM User is offline

yes i flush the rear ac, if my fan clutch was bad would that not cause the engine to run hot i am running at normal temps

mxz583 on Mon June 22, 2009 6:45 PM User is offline

what should i see my low and high side be at. the temp is at 90 with 80% humidity

HVargas on Mon June 22, 2009 6:47 PM User is offlineView users profile

Good low is 27-35, high should be 2-2.5x ambient so 180-225.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: Arizona Mobile Air

mxz583 on Mon June 22, 2009 7:25 PM User is offline

i have 60 Low 195 High

mxz583 on Mon June 22, 2009 8:47 PM User is offline

my low side is 60 and my high side is 165 at idle, at about 1500 rpm low is 50 high 225 cooling is poor i think my compressor is bad but have been told by the part store were a got the compressor that the orfice tube is bad i have replaced that 2 times now and ac is the same poor

Chick on Mon June 22, 2009 10:22 PM User is offlineView users profile

Ask the parts guy how long he has been "fixing" ac systems, rather than selling parts.. O tube has nothing to do with your problem, clogged would show low side pressures..

-------------------------
Chick
Email: Chick

---------------------------------------------

Freedoms just another word for nothing left to lose

TRB on Mon June 22, 2009 10:36 PM User is offlineView users profile

Could you please explain your flushing procedure? I'm concerned you left some flushing agent behind along with a few issues the others have mentioned.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

mxz583 on Mon June 22, 2009 10:59 PM User is offline

I used some flushing solvent with a flushing canister i blew the solvent thru the lines and everything till everything look clean than a blew air at low pressure till the solvent was gone

bohica2xo on Tue June 23, 2009 12:28 AM User is offline

1) Aluminum shards on the orifice tube screen. A good chance most of the debris stayed in the condensor. Pull the orfice & check the screen again. If you find more metal the condensor is full of it.

2) "Flushed" rear system - it sounds like it was flushed through the long lines, TXV, evaporator, lines - all still assembled?

3) Remanufactured compressor or new?


The best answer at this point is a return to square one. Break the system down into individual parts, and flush to bare metal. This means pulling the rear evaporator & removing the TXV. Replace the condensor. New accumulator. Personally I would replace the TXV & compressor with new units. Tim has a nice replacment for that compressor. Do it right, do it once.

B.

-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Edited: Tue June 23, 2009 at 12:29 AM by bohica2xo

mxz583 on Tue June 23, 2009 3:15 PM User is offline

my low side is 60 and high side 170 vent temp 60 i have poor cooling. low side is high but can not figure out why the guy i got the new compressor from first said orfice tube now tells me that condenser is restricted i can't see how with a high side of 170. should my high side be a lot higher if that was true i still think my compressor is on the way out

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.