Automotive Air Conditioning Information Forum (Archives)

Camman on Mon July 19, 2010 6:35 PM

Year: 2003
Make: Chevy
Model: S10
Engine Size: 2.2L
Refrigerant Type: R134Aa
Ambient Temp: 115
Pressure Low: 60
Pressure High: 150
Country of Origin: United States

So I have a 2003 chevy s10 2.2l with a v7 compressor. I drive a delivery route and last friday my a/c started blowing warm at the begining of my route! That sucked because it was like 105. The a/c was blowing cooler than ambient, but only by 10 to 15 degrees. It also blows slightly cooler when the rpms are high. This happened to my original compressor last summer so I immediately thought rcv valve.

When I got home that night I threw on the gauges and I had low at 60 and high around 140. This, I thought, confirmed my rcv valve theory. So I ordered an mc-853 control valve from XXXXXXXX and thought I would be good to go.

I suffered through a whole week of 115 to do it this weekend and well... I still have just mediocre cooling. My gauges now show low 70 and high 150! So now I am scratching my head... the compressor is not making any weird noises and when I pulled the original rcv valve out I didnt notice any black death on it. This is a replacement chinese compressor which doesnt seem to be detonated or anything.

Do you think I may have gotten a faulty valve? Please help I am stumped by this! Thanks alot!

Edit by Moderator: That site blocks our name on their site so we return the favor.

Edited: Mon July 19, 2010 at 6:45 PM by Automotive Air Conditioning Information Moderator

HVargas on Mon July 19, 2010 6:38 PM

What was your static pressure of the system and did you pull the orifice tube to check it's condition as well?

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Camman on Mon July 19, 2010 6:51 PM

static pressure at about 95 when ambient temp was 80-90 dont know exact outside temp it was 2 in the am. I did not pull the orifice tube this time because I thought that a blocked tube would show low to vacuum on low and higher than normal on high. Thanks for the help!

iceman2555 on Mon July 19, 2010 10:10 PM

Considering the posted ambient temp and pressures...seems like a serious undercharged system. How was the system recharged?
Stated that this same issue occurred last year ? What repairs were made at that time? What parts were replaced and how was the system prepared for the new compressor?
Have seen some of the 'off shore' V's with damaged or broken yoke/slider bearings. This can force the compressor into a fixed displacement unit by not allowing the swash to move. However, normally when this occurs the compressor locks.
It is quite possible to have a 'clean' orifice tube and the condenser still be restricted with debris. If the condenser is restricted...there is a good possibility of internal compressor damage due to lack of lubricant. A system restriction may contribute to a decrease of refrigerant/lubricant migration within the system.
A restricted condenser may be indicated by the pressures and lack of cooling experienced. Liquid line pressures often do not indicate a condenser inlet restriction. If you posses a method of testing the temperature of metal....test the inlet and outlet temps of the condenser. Should see app....23-28 degree drop. Excessive temp drops normally indicate a restriction.
First, need to know if the system is completely and fully charged.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Camman on Tue July 20, 2010 2:18 AM

my apologies the static pressure is 120 and the temperature is over 90 tonight I am sure, my thermometer on my multimeter says 95.

Last summer my original compressor went out, the readings if I remember correctly were about 95 low and 105 hi. The high side would actually decrease with rpm. I replaced the compressor with a chinese one(money), orifice tube, o rings, and dryer. This worked a champ for 3 months or so, then it went out again... company sent me another compressor and it worked until last week or about half a summer with about 10,000 miles. The system both times was flushed with aerosol cans and vacuumed for 1 hour with an hour of "rest" time to check for leaks.

I recharged the system with a scale and cans... but to be honest the truck cools really well with 2 cans in it(the auto store cans lol). This time I put 1.75 lbs in which is what the sticker calls for, I am 99.99 percent sure there is the correct amount of freon in the system, and I have no leaks.

I unfortunetaly do not have a laser thermometer thing but I guess maybe I should pick up a cheapie from harbor freight.


edit: I touched the high side line and its warm but not too hot that I cant keep my hand on it, the outlet from condensor feels like ambient or maybe just a touch warmer. However I guess it couldn't cool past ambient so thats kind of a lame test. I can pick up a pyrometer from harbor freight ill do that tomorrow I guess. I sure hope this thing doesn't have a blocked condensor. I still can't wrap my head around a blocked condensor causing lower high side pressures. I still have my original compressor which I am pretty sure has a bad rcv, should I try putting the new rcv in that and see what happens?


Moderator: I am sorry for mentioning the other company, I will order from you guys from now on... I just didn't know about this place until today, you certaintly couldn't be any less personable lol.

Edited: Tue July 20, 2010 at 4:18 AM by Camman

Camman on Wed July 21, 2010 6:00 AM

ok so there is a new development! The compressor has a catch in it now when I turn the clutch. So I guess the bearings are bad but somehow it didn't lock up the compressor completely. I am going to try to put on my old compressor with a new valve that I bought and see if it works, but I am definetaly going to have to buy some parts.

I am going to go ahead an replace everything I think if the compressor detonated as I want to fix this and have it last another few years like the oem. So I am looking at ackits so I can throw back some support. I like the price on the rebuilt compressor but I don't want to buy a pos china quality like I did last time. Are the rebuilt units quality or is the only way to get quality to buy the oem? Also where can I get new lines as I don't see them listed for my truck. thanks alot!