Announcement

Collapse
No announcement yet.

Cooling system woes

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

    Cooling system woes

    So I've read every post on filling and bleeding the cooling system that i could find. And I can not seem to get my 325e's cooling system working right.

    So I recently picked up my 86 325es. Did the timing belt and cooling system update, and can't seem to get it back to performing quite right. Driving around, its never got to the red, but it get to or past the high line in the mid section. Sitting at idle it will get to the red fairly quickly. Parts replaced were;

    expansion tank, all hoses, water pump, t-stat, clutch fan, temp sensors.

    I've been trying to bleed it for a few days now (well weeks actually, but really focusing for the past few days). Front of car up on ramps. System filled up via the upper radiator hose, then filled up via the expansion tank. Run til just before its in the red, then shut down and open the bleeder screw until its not pure steam, or lots of bubble, just a flow of coolant. Close it down, let it cool some more, then start it up and do it all over.

    The thing is the radiator never gets hot, heck or even warm. Its like the thermostat isn't opening at all. But its a brand new t-stat. The other issue that makes me think the t-sat isn't opening is the level in the expansion tank never changes, the lower rad hose never gets warm, the upper hose gets warm, but not super hot. Only thing that gets hot is the hose from the pump to the t-stat housing and the t-stat itself.

    One known issue is my secondary fan isn't working, thats a problem I know, but it shouldn't be causing this.

    What am I missing?
    2002 530i - Daily
    2013 Ford Flex Ecoboost - wifes/family hauler
    1986 325es - fun car (or money pit depending on who you ask)

    My build thread - https://www.r3vlimited.com/board/sho...d.php?t=422370

    #2
    Even a brand new tstat can malfunction so test it....and if you are getting steam out of the bleeder you are cooking your engine which typically causes it to warp...so stop that.

    I drill a 1/16 hole on the top of the stat flange and have never...and I mean NOT EVER had a bleed issue in 20+ years of owning at least 1 e30
    Seat Shocks....I have passed the baton to John Christy from Ninestitch. Email John or Garrett at ninestitch1@gmail.com

    https://www.r3vlimited.com/board/sho...86#post4944786
    Alice the Time Capsule
    http://www.r3vlimited.com/board/showthread.php?t=360504
    87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220

    Comment


      #3
      Originally posted by jeffnhiscars View Post
      Even a brand new tstat can malfunction so test it....and if you are getting steam out of the bleeder you are cooking your engine which typically causes it to warp...so stop that.

      I drill a 1/16 hole on the top of the stat flange and have never...and I mean NOT EVER had a bleed issue in 20+ years of owning at least 1 e30
      I will try the hole in the t-stat, and being more carefully about how hot I let the system get.

      Probably won't be able to touch it for a couple weeks now though. Have something going on every night this week, and then go on vacation Friday for a week. So will update in a couple weeks once I make some headway on it.

      Sent from my Nexus 6P using Tapatalk
      2002 530i - Daily
      2013 Ford Flex Ecoboost - wifes/family hauler
      1986 325es - fun car (or money pit depending on who you ask)

      My build thread - https://www.r3vlimited.com/board/sho...d.php?t=422370

      Comment


        #4
        Put the thermostat in a pot of water and chuck it on the stove. Watch it open as the water heats up and watch it close as the water cools down.

        I've never drilled any holes, cracking the little bleed screw once or twice has been enough on my m20.

        Comment


          #5
          Well I ended up taking the day off, so I took the tstat out and drilled a 1/16 hole in it. Reinstalled it before I saw the advice to put it in a pot of water to see if it functioned properly. Wish I had done that.

          Anyway after the whole and refilling then warming up and bleeding, it did seem to get more air bubbles out with the whole in there. But overall it seems worse. Warmed it up and bleed it about 5 times. Then took it on a test drive and it got past the 3/4 mark before I even got out of the neighborhood. Before while driving it would get up there but never really go past. I turned around and it was approaching red when I pulled into the driveway. Shut it down and put a box fan in front of it. And called it a day.

          I guess it's possible I just have a huge air pocket. But it sure seems odd that the radiator never gets warm. 8 guess I have to pull it out again and do the hot water test on it. If that shows that it does work, I guess that means I just have a lot of air in there and just need to keep bleeding? Or could there be something else I'm missing?

          Sent from my Nexus 6P using Tapatalk
          2002 530i - Daily
          2013 Ford Flex Ecoboost - wifes/family hauler
          1986 325es - fun car (or money pit depending on who you ask)

          My build thread - https://www.r3vlimited.com/board/sho...d.php?t=422370

          Comment


            #6
            The radiator won't get warm until the stat opens up so that may be your problem. Have you made sure the hvac temp control knob is set to fully open ?
            Seat Shocks....I have passed the baton to John Christy from Ninestitch. Email John or Garrett at ninestitch1@gmail.com

            https://www.r3vlimited.com/board/sho...86#post4944786
            Alice the Time Capsule
            http://www.r3vlimited.com/board/showthread.php?t=360504
            87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220

            Comment


              #7
              You could always take the thermostat out and go for a drive.

              And I’ve always bled the system on our ‘87 pretty easily, I open the bleed screw with the motor running which you specify that you only open it after shut down.
              My son has the 1987 325e, 2 door, 5speed
              I daily the 1989 325i, 4 door, 5speed

              Comment


                #8
                +1 big time. Engine has to be running to bleed
                Seat Shocks....I have passed the baton to John Christy from Ninestitch. Email John or Garrett at ninestitch1@gmail.com

                https://www.r3vlimited.com/board/sho...86#post4944786
                Alice the Time Capsule
                http://www.r3vlimited.com/board/showthread.php?t=360504
                87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220

                Comment


                  #9
                  Yes, HVAC controls are set to full hot. Fan on 4. Air gets warm, but not really hot.

                  I've been doing both, opening bleed screw while it is running and after I turn it off. Open it, if its air/bubbly coolant, I leave it open until it is just a stream of coolant, then close it. Doing this both with engine running, and after I shut it down.

                  Should I not do this after I shut the engine down?

                  Its got to be either a bad tstat or a huge air bubble. The car drove fine from Dallas to Oklahoma City when I bought it. So it has to be something I did to it.

                  Can you even run it without the tstat in there, won't it leak? The o-ring on the tstat is what seals the housing isn't it? It probably won't leak much though, and worth a try. If it still gets hot then, it means there is a lot of air trapped in the system right? Because otherwise, it will constantly run though the rad and never really warm up correct?
                  2002 530i - Daily
                  2013 Ford Flex Ecoboost - wifes/family hauler
                  1986 325es - fun car (or money pit depending on who you ask)

                  My build thread - https://www.r3vlimited.com/board/sho...d.php?t=422370

                  Comment


                    #10
                    I admit, even though I’ve changed thermostat s and removed/replaced the thermostat housing on our two cars, I don’t know for a fact how much coolant would leak without the thermostat in there. I was just going for a quick easy way to confirm that your coolant is flowing without the threat of overheating the engine.
                    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
                      I admit, even though I’ve changed thermostat s and removed/replaced the thermostat housing on our two cars, I don’t know for a fact how much coolant would leak without the thermostat in there. I was just going for a quick easy way to confirm that your coolant is flowing without the threat of overheating the engine.
                      Well if I am taking it out, I can just try the putting it in hot water trick, to see if it opens and closes properly. I don't actually have to drive around to see if the tstat is the problem. Although it would be interesting, if it does prove to be working, to run the car without it, and see what happens. I wouldn't need to drive it, just idle it. Should flow though the rad constantly, I would assume the rad would get warm, but the coolant temps shouldn't get very hot. Unless there is a blockage of some kind, air bubble or solid.

                      I already know the rad isn't clocked because I filled it via the top hose, with the bleeder screw open, and coolant came out the bleeder. So it filled the rad and went up the lower hose to the tstat.
                      2002 530i - Daily
                      2013 Ford Flex Ecoboost - wifes/family hauler
                      1986 325es - fun car (or money pit depending on who you ask)

                      My build thread - https://www.r3vlimited.com/board/sho...d.php?t=422370

                      Comment


                        #12
                        Is it at all possible that you have installed the T-stat backwards? You would definitely be overheating if that's the case. Something to consider and eliminate.
                        Jon (OO=[][]=OO)
                        1992 325ic white, stock with a 5-speed swap
                        Palm Beach County

                        Comment


                          #13
                          Originally posted by jgilber0 View Post
                          Is it at all possible that you have installed the T-stat backwards? You would definitely be overheating if that's the case. Something to consider and eliminate.
                          I do believe they will fit in backwards, you can remove it and just reinstall the O ring and being able to fill a radiator doesn't mean it's not partially clogged. Hit it with an iR gun to see if it's even temp everywhere.

                          You've got lots,of small passages that can greatly reduced cooling capacity. The radiator is actually part of a 100k total cooling system update and the hand ful I've replaced have all made a difference, even on cars that did not overheat.
                          Seat Shocks....I have passed the baton to John Christy from Ninestitch. Email John or Garrett at ninestitch1@gmail.com

                          https://www.r3vlimited.com/board/sho...86#post4944786
                          Alice the Time Capsule
                          http://www.r3vlimited.com/board/showthread.php?t=360504
                          87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220

                          Comment


                            #14
                            Originally posted by jeffnhiscars View Post
                            I do believe they will fit in backwards, you can remove it and just reinstall the O ring and being able to fill a radiator doesn't mean it's not partially clogged. Hit it with an iR gun to see if it's even temp everywhere.

                            You've got lots,of small passages that can greatly reduced cooling capacity. The radiator is actually part of a 100k total cooling system update and the hand ful I've replaced have all made a difference, even on cars that did not overheat.
                            OK, I just double checked every pic, video and diagram I could find online, and I do have the t-stat installed the right direction. Honestly at this point I was hoping I didn't since that would be an easy fix.

                            You are right in that I wasn't thinking about the radiator right, it could still have lots of clogged tubes, thus greatly reducing it's efficiency. Although I would think that if anything was going through it the lower hose running to the t-stat would still get warm, actually downright hot if it's not cooling well. But that hose barely warms up at all.

                            Well like I said, I won't be able to touch it for over a week. So hopefully then I can figure it out.
                            2002 530i - Daily
                            2013 Ford Flex Ecoboost - wifes/family hauler
                            1986 325es - fun car (or money pit depending on who you ask)

                            My build thread - https://www.r3vlimited.com/board/sho...d.php?t=422370

                            Comment


                              #15
                              You forgot one of the most important things, the gauge cluster. The E30 gauge cluster is extremely common to read too high. This is due to oxidized gauge connectors, loose grounding and failing SI board which controls the gauge.

                              Until the SI board and cluster are refurbished, you cannot trust a 30 year old failing cluster.
                              Owner - Bavarian Restoration
                              BMW and European Electronics Repair and Restoration
                              www.BavRest.com
                              My Feedback Thread
                              Our Facebook!
                              Follow our Instagram!

                              Comment

                              Working...
                              X