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    New converted AC not cold enough

    Curious to see what vent temps you guys are seeing after your R134a conversion. I'm in Arizona so with ambient air at 105 degrees at best I'll get 60ish at the vent. I have to be moving for that. 70ish at idle. My e46 is showing 40 degrees at the vent. I replaced everything, new lines, dryer, evap, condenser, new not cheap sanden compressor. Had it charged at an AC shop. So is 60 the best I can expect or do I need to check something like that PITA probe behind the dash in the evap thing?
    '90 325is

    #2
    In e30 my problem with ac is the air recirculation not 100% flaps closed and still air pass the blower casing and degrade ac outcome, i got fed up and only closing the vents under the windshield works for me temporarily.

    Check that you have 0 fresh air sucked by the blower motor since your system is all new.

    Comment


      #3
      Did you replace the TX valve too? and or is it defiantly an r134a one? and is the pressure switch the right one for r134a?

      What did the shop say? if its not cold and is an issue any of the pressure components it should have been picked up with the gauge set.

      For what its worth I converted to R134a with the sanden as well with new tx valve and dryer, but reused the original r12 condensor and evap. And its freezing cold. coldest AC ive had in a car for a long time.

      Comment


        #4
        Originally posted by Hoffbrohaus View Post
        Curious to see what vent temps you guys are seeing after your R134a conversion.
        As the other guys mentioned, depends on how far your R134a conversion extends.
        I ended up doing a full R134a retrofit.
        Vent temps depend on ambient & operating conditions - mine were about 42F - see detail here

        Even with a PF condenser, the system benefits with the aux fan set to run on high.

        What condensor speed are you running - hi or lo?
        Also what evap fan speed are you running when you take the measurements?


        E30 320i vert
        But daily drive is Volvo V60 Polestar

        Comment


          #5
          Originally posted by ADEN View Post
          In e30 my problem with ac is the air recirculation not 100% flaps closed and still air pass the blower casing and degrade ac outcome, i got fed up and only closing the vents under the windshield works for me temporarily.

          Check that you have 0 fresh air sucked by the blower motor since your system is all new.
          How do I check that? turn recirc on, fan on 4 and feel the vents outside by the windshield for suction? (I'll try when I get home from work)


          Originally posted by e30davie
          Did you replace the TX valve too? and or is it defiantly an r134a one? and is the pressure switch the right one for r134a?

          What did the shop say? if its not cold and is an issue any of the pressure components it should have been picked up with the gauge set.

          For what its worth I converted to R134a with the sanden as well with new tx valve and dryer, but reused the original r12 condensor and evap. And its freezing cold. coldest AC ive had in a car for a long time.
          I replaced the condenser, expansion valve, pressure switch, dryer/receiver, o-rings, and evap core. all R134A parts. What is the TX valve? The shop told me to bring it back for another pressure check and I have not yet, I just hesitate because they charged me so much before, I guess I should bring it back and I'll make it clear they can't charge me to check their work.

          Even with a PF condenser, the system benefits with the aux fan set to run on high.

          Originally posted by tzantushka
          What condenser speed are you running - hi or lo?
          Also what evap fan speed are you running when you take the measurements?
          The Aux fan is stock and set to run the way it is from the factory. Ii thought it would automatically run on high with the AC button on, certainly when it's 105 degrees out would it not?
          Fan speed was at full speed, 4, but doesn't matter same temps at fan speed of 2.
          '90 325is

          Comment


            #6
            TX valve = expansion valve. so yer sounds like you changed it. sadly you will only really be able to rule out mechanical issues with the gauge set. suprised the shop let it go if its not cold?

            I must admit that i had to dodgy the wiring in my car and the aux fan just runs whenever the AC is on.

            Comment


              #7
              [QUOTE=Hoffbrohaus;n10028877]

              How do I check that? turn recirc on, fan on 4 and feel the vents outside by the windshield for suction? (I'll try when I get home from work)

              Just seal them temporarily with anything and check if the vents reading any cooler. small amount of outside warm air can increase ac vent temp.



              stock fan starts at low speed with the ac on unless the rad. temp reached 105c then it will go high speed this is not going to help ac in high ambient temperatures. Try to bypass the temp switch in radiator( 3-wire connector) by using a jumper wire to activate the high speed or jumber wire from the low speed fuse to the high speed fuse (google) and see if this helps.

              Comment


                #8
                OK making some progress. I tested the external intake vents. Put some plastic over them. With recirc off the plastic gets sucked tight, recirc on the plastic is loose as could be. So no external air causing hotter AC. Next, checked aux fan. Looks like a PO replaced the radiator connector so I can't see the wire colors. See attached picture. If I jumper 1&3 I get low speed. If I jumper 2&3 I hear a click in the relay but the fan doesn't move. Looks like no high speed! So I'll start searching for that fix now. Edit: just swapped K1 and K6 relays and both low and high speed work. I'll see my temp tomorrow when we hit 106. Sent from my SM-G996U using Tapatalk
                Last edited by Hoffbrohaus; 09-13-2021, 10:31 PM.
                '90 325is

                Comment


                  #9
                  No luck. Was 106 today and even with the aux fan on high my AC vent temp didn't change. Stayed at 60. Sent from my SM-G996U using Tapatalk
                  '90 325is

                  Comment


                    #10
                    Just for reference, do you have the recirc on when checking the vent temp? What is the fan speed?
                    1992 325i Cabrio
                    1988 320i Touring
                    2000 M5
                    1977 530i
                    2015 328i - Euro Delivery/Performance Center Delivery
                    BMWCCA
                    E30CCA

                    Comment


                      #11
                      Did they pull a vacuum and recharge or just fill it up? After I did my conversation the 1st shop I took it to filled it using a bottle and gauges but it still didn’t get cold. 2nd shop pulled vacuum and recharged using a recharging machine. My temps are now in the low 40’s.
                      sigpic84 325e

                      Comment


                        #12
                        Originally posted by cory58 View Post
                        Just for reference, do you have the recirc on when checking the vent temp? What is the fan speed?
                        Recirc on. Fan speed at 2 Sent from my SM-G996U using Tapatalk
                        '90 325is

                        Comment


                          #13
                          Originally posted by 808ETA View Post
                          Did they pull a vacuum and recharge or just fill it up? After I did my conversation the 1st shop I took it to filled it using a bottle and gauges but it still didn’t get cold. 2nd shop pulled vacuum and recharged using a recharging machine. My temps are now in the low 40’s.
                          Well I thought they would have to pull a vacuum since it was a whole new system. But maybe not? They said they checked pressures but does that mean they just filled it and see the right pressure? I will call them and ask but they may just say they pulled vacuum when they didn't. Might be worth taking somewhere else. Or going turbo and deleting the AC 🤔 Sent from my SM-G996U using Tapatalk
                          '90 325is

                          Comment


                            #14
                            Originally posted by Hoffbrohaus View Post
                            Well I thought they would have to pull a vacuum since it was a whole new system. But maybe not? They said they checked pressures but does that mean they just filled it and see the right pressure? I will call them and ask but they may just say they pulled vacuum when they didn't. Might be worth taking somewhere else. Or going turbo and deleting the AC 🤔 Sent from my SM-G996U using Tapatalk
                            Yeah, when they pulled the vacuum they confirmed that it wasn't leaking.
                            sigpic84 325e

                            Comment


                              #15
                              Is your auxiliary fan stock or aftermarket? When it comes on, does it blow the right way? When I installed my aftermarket, it came as a sucker, the directions had me reverse the blades AND reverse the wiring. I missed that second step, chased my tail for a very long time. About the 10th time I went through to verify EVERYTHING again I noticed the auxiliary fan was pulling air out versus pushing air through.
                              2004 525i Manual - 1985 325E Coupe Manual

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