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  • #46
    Originally posted by RAD2LTR View Post
    Thread revival...

    Its been hot here lately and I've been thinking some a/c might be nice. The a/c has never worked in the car since I bought it, however it was recharged in November 2011, only a couple weeks before I bought it. (Since it was in Canada, its hard to say if it was working then or not. The air temp was colder than the a/c temp so either way, it was going to feel cold.

    I've done a little poking around, but the truth is, I honestly don't know if it has a charge on it or not. The light lights up when pressed, I can hear the compressor kick on, but the temp doesn't change. The aux fan also doesn't kick on with the a/c button pushed, but it does run when the temp gets high enough at idle. I replaced the switch for it last year (It didn't work at all last year), I think I replaced both switches on the thermostat now that I think about it. The metal pipes that come from the compressor also don't seem to change temp either. I assume one would be warm and the other very cold. As a side note, during the winter I've kicked the a/c on to defog the windows, but it hasn't really done anything. This leads me to believe something isn't opening or closing.

    My hunch is, its a valve issue and perhaps a tired air drier. Its still an R12 system according to the receipt I have from the previous owner. I do cycle the system on and off about once a week (I let it run for 15 minutes or so every time) even though its never worked in an effort to keep the seals lubed. My guess is that the pressure is low, but from the sound of it, if it were low, the compressor won't engage. All the wires appear to be plugged in where they should. I've never delt with a/c before so I'm a little at a loss here.

    Thanks,
    Will
    Will,

    If you plan to do A/C work on your own, you'll have to start by getting a set of gauges so you can measure both low and high side pressures. That will give an idea of what is wrong with the system.

    Comment


    • #47
      When you convert from R12 to R134a, you also have to remove the mineral oil in the compressor and replace it with synthetic refrigerant oil, since the R134a won't mix with the mineral oil. If you leave the mineral oil in the compressor and add the synthetic oil, it will make a huge mess.
      Larry

      Comment


      • #48
        I don't have the $ to convert to R134. Id pull the whole system out and save the 86 lbs before I'd convert to R134. The system does have pressure, not sure how much. A set of gauges appears to be pretty cheap but we might have a set at work I can use. I'm suspicious of the expansion valve. I think it might be stuck closed since both hard lines are warm to the touch.

        Will
        '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
        '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
        '88 M3

        Comment


        • #49
          Here is what you should do. I am a GC and I have had my HVAC subs school me on this. You will need a set of gauages and a vacuum pump and micron gauge.

          1. verify that everything is getting power as it should. The compressor will engage, etc.

          2. pull vacuum on the system. You will need this micron gauge.

          http://www.ebay.com/itm/Supco-VG60-E...ht_3585wt_1546

          It should stay in the green area for at least an hr.

          3. If it is a sealed system, then remove compressor and drain the oil. replace the oil with this:

          http://www.es-refrigerants.com/produ...-3/details.asp

          4. Re-install compressor, pull vacuum again and use the micorn gauge. make sure it holds.

          5. Re charge with this: http://www.es-refrigerants.com/produ...nt/details.asp

          use the conversion tables to make sure you dont overcharge. you have to fill by weight, so you need a scale.

          If you have leaks in the system then, you you have to find them, replace hoses, etc.

          Envirosafe blows cold, r134 will give you black death if you spring a leak sometime down the road as moisture in the system and it combining its pag oil with traces of r12 mineral oil. If you completely remove all the mineral oil you csn use 134a, however its not as cold as enviro-safe. Envirosafe is propane and oil, but has a higher flash point than 134a, so dont worry

          chucker
          89 m3 "Ms. Bavaria"..... Cinnabar w/ Black Guts, Evo 2 cam, Miller War Chip, CF Intake, What's a cat?
          12 Avalanche "OJ" ..... Black on Black, Loaded, and Runs
          08 335i "Vanessa" ..... Black with Buckskin guts
          08 Jetta 2.0 Turbo "Joan Jetta"..... Red with Tan Guts

          Comment


          • #50
            I took the car to a place that knows E30s. They said that since the compressor is turning, and the air out of the vents is slightly colder than the ambient air temp, its just low on charge. They didn't have any way of adding the Freeze 12 to the system however. Just to be sure, the low side valve is on the hard line that runs around the front of the strut tower correct. The high side line runs down to the dryer and that way.

            Just to make sure, I can add the Freeze 12 to the r12 that is currently in the system correct? I've read that freeze 12 is R134 with a different oil so I'm a little hesitant to add it since I thought R12 and R134 were totally incompatible.

            Thanks,
            Will
            '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
            '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
            '88 M3

            Comment


            • #51
              Lots of good advice here. BTW the dealer sells a kit that converts the AC system to R134a. I did this and kept the original compressor and it works fine in 90 degree heat. There is a slow leak somewhere but I top it off with more refrigerant each Spring.
              There'll be Spandex jackets one for everyone ...

              Comment


              • #52
                dont use freeze 12. its no more than 134a and r142 mixed so it will be somewhat compatible with r12. use the es stuff i recommended above. its a hydro carbon so its lighter, more efficient. mixes with all oils, has a higher flash point than 134a.

                r134a does not belong in our cars, risk of black death, small condensor.

                chucker
                89 m3 "Ms. Bavaria"..... Cinnabar w/ Black Guts, Evo 2 cam, Miller War Chip, CF Intake, What's a cat?
                12 Avalanche "OJ" ..... Black on Black, Loaded, and Runs
                08 335i "Vanessa" ..... Black with Buckskin guts
                08 Jetta 2.0 Turbo "Joan Jetta"..... Red with Tan Guts

                Comment


                • #53
                  Originally posted by Chucker View Post
                  dont use freeze 12. its no more than 134a and r142 mixed so it will be somewhat compatible with r12. use the es stuff i recommended above. its a hydro carbon so its lighter, more efficient. mixes with all oils, has a higher flash point than 134a.

                  r134a does not belong in our cars, risk of black death, small condensor.

                  chucker
                  I'm not looking to pull the whole 9 yards apart. I just need a recharge. No one has R12 to do a recharge. I'm not going to convert it, its not worth it. If I needed to take something apart, sure, I'll go with the other stuff. I'm not looking to fix something that isn't necessarily broken. I think what happened is that the previous owner paid to have the thing charged, and the shop said they did, but didn't do it. That is my best guess. If there were a real leak, there would be no pressure at all in the system after a year and a half (assuming they did recharge it). I'm not really interested in throwing several hundered dollars at something that isn't broken. If, there is actually an issue, ok, fine I'll fix it right, but at this point, there is no issue other than not enough R12 in the system.

                  Will
                  '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
                  '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
                  '88 M3

                  Comment


                  • #54
                    Originally posted by RAD2LTR View Post
                    I'm not looking to pull the whole 9 yards apart. I just need a recharge. No one has R12 to do a recharge. I'm not going to convert it, its not worth it. If I needed to take something apart, sure, I'll go with the other stuff. I'm not looking to fix something that isn't necessarily broken. I think what happened is that the previous owner paid to have the thing charged, and the shop said they did, but didn't do it. That is my best guess. If there were a real leak, there would be no pressure at all in the system after a year and a half (assuming they did recharge it). I'm not really interested in throwing several hundered dollars at something that isn't broken. If, there is actually an issue, ok, fine I'll fix it right, but at this point, there is no issue other than not enough R12 in the system.

                    Will
                    The conversion the dealer sells is not that expensive or all that tough to install. You can't get R12 anymore here in NJ unless you know an HVAC guy. You're in CA so I'm sure R12 is just as tough if not tougher to get.
                    Last edited by njboy; 07-03-2013, 01:31 PM.
                    There'll be Spandex jackets one for everyone ...

                    Comment


                    • #55
                      Keep a hawk eye on craigslist. I managed to score 8 small cans of real R12 (the packaging was ancient) for about $110. The guy was a retired mechanic and even threw in his old R12 manifold gauge (recharge equipment).
                      Yes, not legal to sell to R12 without the permit, but I must have left it my other car.

                      Comment


                      • #56
                        Will, you wont have to do anything more than pull a vaccum and charge with ES 12a refrigerant. Its mixes with all oils. It doesnt draw mositure if you ever have a leak, it just leaks out... No risk of black death as with freeze 12, r134a crap.

                        its more effiecient than r12, freeze 12, r134a, etc... You barely feel the compressor kick in. And did I say blows cold. I put a parallel flow on last summer when I got all that freeze 12 crap out and its cold brother, probably 38 degrees. way cold in asheville, nc.

                        chucker
                        89 m3 "Ms. Bavaria"..... Cinnabar w/ Black Guts, Evo 2 cam, Miller War Chip, CF Intake, What's a cat?
                        12 Avalanche "OJ" ..... Black on Black, Loaded, and Runs
                        08 335i "Vanessa" ..... Black with Buckskin guts
                        08 Jetta 2.0 Turbo "Joan Jetta"..... Red with Tan Guts

                        Comment


                        • #57
                          I just picked up a can of R12 and a set of R12 gauges and hoses for $45. My next question is, where is the sight glass? I'm told its on top of the dryer, but I can't see one. Is it the hex head bolt that sits directly on top of the valve? I'm just waiting on a can tap for the type of can I have (I have a screw on tap, but the can is a clamp type.) It should be here later in the week.

                          By the way, if I do have to pull the whole thing apart and I can find someone to evac the R12, I will use the Enviro-safe stuff.

                          Will
                          '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
                          '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
                          '88 M3

                          Comment


                          • #58
                            will, you will need 1.94 lbs ( check your tag under the hood to be sure) of r12 to full charge if empty. If not empty you have to charge by ambient temperature and pressures, both high and low. Do you have a chart of our pressure ranges?

                            if you go with Enviro safe you have to charge by weight as well. I use a scale. The stuff is so cheap I just evacuate, pull vacuum and put in the correct amount by weight. You need to follow their conversion tables. You wont use the same its lighter stuff.

                            the sight glass may be under a little black cover on top of the drier behind the passenger headlamp. Take a pocket knife and pry up.

                            if you need a picture of mine send me your email address.

                            You do know the high and low side taps? Very dangerous to try to charge on the high side!!

                            chucker
                            89 m3 "Ms. Bavaria"..... Cinnabar w/ Black Guts, Evo 2 cam, Miller War Chip, CF Intake, What's a cat?
                            12 Avalanche "OJ" ..... Black on Black, Loaded, and Runs
                            08 335i "Vanessa" ..... Black with Buckskin guts
                            08 Jetta 2.0 Turbo "Joan Jetta"..... Red with Tan Guts

                            Comment


                            • #59
                              Originally posted by Chucker View Post
                              will, you will need 1.94 lbs ( check your tag under the hood to be sure) of r12 to full charge if empty. If not empty you have to charge by ambient temperature and pressures, both high and low. Do you have a chart of our pressure ranges?

                              if you go with Enviro safe you have to charge by weight as well. I use a scale. The stuff is so cheap I just evacuate, pull vacuum and put in the correct amount by weight. You need to follow their conversion tables. You wont use the same its lighter stuff.

                              the sight glass may be under a little black cover on top of the drier behind the passenger headlamp. Take a pocket knife and pry up.

                              if you need a picture of mine send me your email address.

                              You do know the high and low side taps? Very dangerous to try to charge on the high side!!

                              chucker
                              The system is not empty, hence the reason I'm attempting to recharge it as is. The high pressure side is the one with the tap coming up the passenger side inner fender, the low side is the one that comes up from the compresser and around the strut tower I assume. I have not found an ambient air temp chart. I was looking through the BMW online shop manual last night and only found one in BAR rather than psi/degrees F. The blue hose goes to the low side, red to the high, and yellow is the feed line. I'm assuming I attach the can to the yellow and it will feed through the gauge set into the low side. The pressures being about 30 psi on the low side and ambient temp times a conversion factor on the high side.

                              I haven't put the gauges on the taps yet to see how much pressure was in the system, I wasn't sure if I could do that without losing a significant amount of freon. I'm guessing I can, but I want to have everything on hand before I did.

                              The guy I bought the stuff from does a/c on commercial trucks. He commented that one can almost just use the sight glass to get the pressure right. Fill till the foam/bubbles go away. This should happen at just about the right pressure on both sides.

                              I'll shoot you an email about the sight glass, I don't see any thing to pry up on my drier.

                              Thanks,
                              Will
                              '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
                              '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
                              '88 M3

                              Comment


                              • #60
                                This thread has some great information for troubleshooting your A/C. It's almost always a good idea to replace your drier before recharging the system. If the compressor seems to be working but you can't get the system charged or cooling, then replace the expansion valve as a first step.

                                http://forums.bimmerforums.com/forum...roubleshooting

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