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1997 Buick Regal. High side rises past 200, slowly goes to 300

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    1997 Buick Regal. High side rises past 200, slowly goes to 300

    I have a 97 Buick Regal LS. Yesterday afternoon I vacuumed down the system, replaced the orifice tube. Buttoned everything up. Vacuumed system down again .
    Go to charge, high side slowly rises to 200 and stays there..The passenger side ac vents are cold on the passenger side and less cold on the driver's side. It's a dual system a/c.
    Early this evening I hook up the guages and notice after a few minutes the high side pressure is slowly rising past 200, goes to 250 , then 300. Trying to solve this. Could be a restriction somewhere. Any input is much welcomed. Thanks.

    Highly unlikely there is a restriction anywhere there shouldn't be. Much more likely you are not shedding heat at the condenser. Restrictions in the high side show up as a rapid temp drop in the line or condenser near where the restriction is, with a marked reduction in cooling.
    Rising pressure over time reflexs heat building up in the system .A quick test is to mist the condenser with a garden hose while watching pressures and temps.
    Lack of heat rejection can be caused by low air flow across the condenser (things like in-op fans, slipping fan clutch, missing air dams or seals or bug screens or other "add-ons" effecting air flow. or a degraded condenser that can't get the heat from the gas to the fins and into the air.
    Pressures without temperatures are meaningless. Only by comparing the air temp going through the condenser, along with the high pressure reading, we can asses how well the condenser is working. Same on the low side.
    Last edited by Cornbinder89; 06-28-2019, 07:48 PM.


      GMP: What was the reason for doing anything to begin with? If to replace "O" tube and vacuum first hope you added some (just enough) 134a so removing tube didn't just suck in air.

      Old as it seems still fussy to have correct weight of charge - a must always. Is it right? Was "o" tube OK or trashed with junk? If not good condenser may and usually takes a hit tossed like a filter as well each time, passages are too small it would do this also.

      Misc: CB89, I thing this Regal is a FWD with two fans probably stay on anytime A/C requested vs belts/fan clutches. High side bouncing around like that there's either air in system or a very wrong charge to rule out while knowing fans are working. Also, is compressor staying engaged or cycling it's close to cut out from high pressure if accurate.

      Again - why was this one touched at all the diagnosing best done first what it will need isn't clear here if just that info,
      MetroWest, Boston