Announcement

Collapse
No announcement yet.

R134 overhaul - weird results

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    R134 overhaul - weird results

    Hi all,

    I converted the e30 to 134 and followed the guide on here.



    I replaced the following parts:

    Compressor rebuilt by Jay Stratton
    Drier
    Paralell flow Condensor
    Expansion valve
    Hoses replaced with barrier hoses a few year ago
    All o-rings with green rings
    Bypassed fan resistor to put fan on high when AC is on
    Blower motor
    Cleaned evaporator coil.


    Okay so I did this correctly. Did not cut corners. Flushed all components of remaining oil and used new o rings, pulled a vacuum for an hour and let it sit to be sure it held. I used manifold gauges to fill with genuine r134 with no additives and used PAG100 as per the Jay Stratton (rebuider of E30 compressors) website.

    When filling to 28oz which is what most everyone recommended for 134, the low side pressure was roughly 70-80 at idle. High side 180. Ambient temps 95 and virtually no humidity (California sun). Vent temps showed 70*. When revved to 3000 vent temps were 60* and pressure showed closer to correct, being 40 low side and 260ish on the high side. I tried to remove some 134 to get closer to correct temps and the results remained the same.

    When driving the temps don't drop below 60.

    I can hear the expansion valve working and when I shoot a IR temp gun at the evaporator core it shows 50*.


    Temps on the condensor are 160* going in the top and 120* coming out the bottom.


    What gives? I'm so tired of throwing money at this AC system.


    ANY help would be so appreciated.


    Jeremy
    Last edited by Garemie; 07-14-2019, 03:31 PM.

    #2
    That's too much oil.
    Apologies - I thought that was 28oz of oil.
    Last edited by uturn; 07-14-2019, 03:11 PM.

    Comment


      #3
      How can you tell?

      So I need to flush the system again and put less oil?

      Comment


        #4
        For what it is worth, some E30s are picky about vent configuration. Try configuring your vents roughly as shown below.
        Attached Files
        2006 GMC Sierra 2500HD 4WD LBZ/Allison
        2002 BMW M3 Alpinweiß/Black
        1999 323i GTS2 Alpinweiß
        1995 M3 Dakargelb/Black
        - S50B32/S6S420G/3.91
        1990 325is Brilliantrot/Tan
        1989 M3 Alpinweiß/Black

        Hers: 1996 Porsche 911 Turbo Black/Black
        Hers: 1988 325iX Coupe Diamantschwartz/Black 5spd

        sigpic

        Comment


          #5
          Interesting. Any idea why the vent position matters?

          Comment


            #6
            Originally posted by Garemie View Post
            Interesting. Any idea why the vent position matters?
            IIRC, it was to prevent freezing the evap in earlier models. Our '88 does it. The '89s and '90 don't.
            2006 GMC Sierra 2500HD 4WD LBZ/Allison
            2002 BMW M3 Alpinweiß/Black
            1999 323i GTS2 Alpinweiß
            1995 M3 Dakargelb/Black
            - S50B32/S6S420G/3.91
            1990 325is Brilliantrot/Tan
            1989 M3 Alpinweiß/Black

            Hers: 1996 Porsche 911 Turbo Black/Black
            Hers: 1988 325iX Coupe Diamantschwartz/Black 5spd

            sigpic

            Comment


              #7
              EDIT: I updated the op to say that I installed a new Paralell flow condensor. Crucial information. Going to try the weird positioning now of vents.

              Comment


                #8
                I struggled with my AC, better now but not perfect. A worth while investment is Rob Siegel's (the hack mechanic) book Just Needs a Recharge. I found it very helpful in understanding more about AC units. One thing in the book, you need to insulate the sensor bulb on the expansion valve to ensure its measuring the temperature correctly. That seemed to help me.
                2004 525i Manual - 1985 325E Coupe Manual

                Comment


                  #9
                  Oh interesting. My expansion valve did not have insulation even before I replaced it.

                  Comment


                    #10
                    Any bubbles in the sight glass?

                    It took me a really long time to get enough 134 into my system to eliminate 90% of the bubbles.

                    My vent temps and pressures are identical to what you have posted. I filled my system with ambient temp of 84º and 82% humidity so I expected warmer vent temps, I hope you can get your system to work like the BMW chart says it should.
                    My son has the 1987 325e, 2 door, 5speed
                    I daily the 1989 325i, 4 door, 5speed

                    Comment


                      #11
                      Originally posted by 325e '87 View Post
                      Any bubbles in the sight glass?

                      It took me a really long time to get enough 134 into my system to eliminate 90% of the bubbles.

                      My vent temps and pressures are identical to what you have posted. I filled my system with ambient temp of 84º and 82% humidity so I expected warmer vent temps, I hope you can get your system to work like the BMW chart says it should.
                      If you put in enough R134a to eliminate all bubbles in the sight glass, your system will be overfilled. I did that at one point. AC performance wasn’t better, and I was getting high side pressures in the 400s.
                      2006 GMC Sierra 2500HD 4WD LBZ/Allison
                      2002 BMW M3 Alpinweiß/Black
                      1999 323i GTS2 Alpinweiß
                      1995 M3 Dakargelb/Black
                      - S50B32/S6S420G/3.91
                      1990 325is Brilliantrot/Tan
                      1989 M3 Alpinweiß/Black

                      Hers: 1996 Porsche 911 Turbo Black/Black
                      Hers: 1988 325iX Coupe Diamantschwartz/Black 5spd

                      sigpic

                      Comment


                        #12
                        I thought that bubbles could also indicate overcharge.


                        I think my plan is to use a chemical flush and start over again.i may flush and go back to r12 with all these new components.

                        Comment


                          #13
                          Hell, I don’t know, I’ve read everything I can find here and I just finished refreshing my a/c system, something I have never messed with.

                          I do know that my system works much better than it did last week. There are bubbles in my sight glass, just very few. My condenser fan will come on, but its not on all the time and I have no idea if its working correctly. Too soon to tell since i just got it all back together last night.

                          I do wish you luck and I hate that you’re having such difficulty. I don’t know much about it but I’m happy to help brainstorm.
                          My son has the 1987 325e, 2 door, 5speed
                          I daily the 1989 325i, 4 door, 5speed

                          Comment


                            #14
                            Can I use this 134 expansion valve with r12 refrigerant ?

                            Comment


                              #15
                              Originally posted by Garemie View Post
                              Can I use this 134 expansion valve with r12 refrigerant ?
                              They don’t actually sell new R12 expansion valves. The new ones technically work, but not well.

                              Have you forced your compressor on by powering the clutch manually? The question that we are trying to answer here is if this is a refrigerant/compressor issue, or an HVAC control issue.

                              Edit: On that subject, I see that you list new dryer, but did you replace the two pressure switches with the one new R134a retrofit one?
                              Last edited by nrubenstein; 07-15-2019, 12:18 PM.
                              2006 GMC Sierra 2500HD 4WD LBZ/Allison
                              2002 BMW M3 Alpinweiß/Black
                              1999 323i GTS2 Alpinweiß
                              1995 M3 Dakargelb/Black
                              - S50B32/S6S420G/3.91
                              1990 325is Brilliantrot/Tan
                              1989 M3 Alpinweiß/Black

                              Hers: 1996 Porsche 911 Turbo Black/Black
                              Hers: 1988 325iX Coupe Diamantschwartz/Black 5spd

                              sigpic

                              Comment

                              Working...
                              X