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M20 Intermittent No Crank Issue - SOLVED!

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    M20 Intermittent No Crank Issue - SOLVED!

    Hey Everyone,
    First off, hope everyone is well during this current pandemic. With all of this time on lockdown I figured I'd tackle a problem that's been bugging me for a while (to the point I haven't been able to drive my e30).

    For the past year or so I have had intermittent starting issues, that have become progressively more frequent. At times (especially when it's hot out it seems) the car refuses to start, even immediately after shutting it off (say to get gas). The internal lights work fine, but turning the key produces nothing from the starter. I've been putting the car in 3rd gear and rolling it back about 2 feet and it typically fires right up full of vim and vigor. The remainder of the time the car cranks and fires without issue as if it just rolled off the lot. At first the once a week occurrence was just a minor inconvenience, but it got to the point where about 50% of the time it won't start without me pushing it around first.

    I checked the battery and connections, which are fine. After a bit of internet research it seems like it might be the starter commutator has gone bad, which would require the dreaded starter replacement. Any other suggestions that would be causing it? I'm thinking it would be weird to have an intermittent grounding or relay issue that would be solved by moving the car.

    Anyway, I appreciate the help. Stay healthy!

    Brian
    Last edited by Longboardmtk; 09-05-2021, 11:02 AM.

    #2
    Worn ignition switch? Maybe jiggle the key in the lock and see if it makes a difference.

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      #3
      Agree with jiggle the key in the lock. If you can't get that to work, I would suspect a bad spot on the starter. One thing to try would be to clean the connections on the battery and make sure the engine ground cable is good.
      2004 525i Manual - 1985 325E Coupe Manual

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        #4
        When it doesn't start next time, try popping the over off the round diagnostic connector and jump the starter there (black with yellow stripe needs to be jumped with red #14 and #11), make sure the car is in neutral and key on. I've had a couple cars come in for intermittent start in the past, and they would start via the diag port when the key was being a lump. The two repairs ended up being different, though, one was an ignition switch, the other was battery and terminals. EDIT: But both would start via the port.
        Last edited by ForcedFirebird; 04-01-2020, 04:56 AM.
        john@m20guru.com
        Links:
        Transaction feedback: Here, here and here. Thanks :D

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          #5
          Probably not very likely, but if the starter is firing consistently and it wont start could it also be some teeth are damaged on the ring gear? Would make sense that it then starts after moving a bit in gear. No idea how likely that would be on these motors though, but I just bolted on a new flywheel and I thought of this post.

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            #6
            If jiggling the key in the ignition while holding it in position to start doesn't help, I hate to bring it to you but it's the starter. I had the same issue, heat soaking starter. Replacing it with a known good used one solved it for me. Twice I had to change the starter, because the first time I bought a brand new one, which turned out to be defective. Good luck to you sir.
            '85 Alpine Weiß 2-door with m20b30 ground up build

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              #7
              To test that, dump a gallon of water on the starter.

              The starter on the E36 318 rat I had started sticking hot, and that was the quick fix to get me home.

              The 'moving' thing, though- do you get a 'clunk' from the starter? That COULD be the solenoid popping out-
              but if the contacts inside are dying, then the motor won't spin. But the solenoid will stick 'out'.
              Rocking the engine lets it drop back in, and try again. Had that happen with an old pickup...

              Same fix, though- new starter.

              t
              now, sometimes I just mess with people. It's more entertaining that way. george graves

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                #8
                ^^^or a hammer and socket extension sometimes works. Usually hitting a starter to get it to work is bad brushes.
                john@m20guru.com
                Links:
                Transaction feedback: Here, here and here. Thanks :D

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                  #9
                  I had a similar issue with my car not starting after I put an OEM exhaust back on it. I bought a brand new starter and still had the same issue. All of the lights and accessories worked no problem but the starter still did nothing. I cleaned the ground to bare metal and had no problems after that. I wish I would have tried that before I bought and installed a brand new starter
                  sigpic84 325e

                  Comment


                    #10
                    Wanted to resurrect this thread since I fixed the problem this morning, and hopefully someone can find this useful in the future. I finally got to the car, turns out being a resident during a pandemic doesn't leave much time for hobbies.

                    First off, thank you for all of the advice, and most of it was very helpful in getting this thing going.

                    So again, my e30 m20 was having an intermittent no crank issue for the past several years, and had been getting worse. Originally jiggling the key, shaking around in the seat would fix it, but eventually putting it in gear and rocking it back and forth helped. When the car had decided it wasn't going to start, the lights and electronics came on as they should with the key partially forward, however when engaging the ignition with the key I got one click from the engine bay and nothing else. This was the order that I progressed in tracking down the problem.

                    If you're following along at home working on your own car, make sure to disconnect the negative battery terminal whenever you're disassembling and reassembling. The starter is otherwise hot at 12v (hopefully).

                    1. Replaced the battery (needed to be done anyway). No change, still sometimes started, sometimes not.
                    2. Checked all of the fuses, no issues. Checked the three relays on the front driver's fender, seemed fine without corrosion.
                    3. Removed, inspected and sanded down chassis and battery grounds. No change, but worth doing anyway.
                    4. Cleaned unit hanging off the front of the block (it was gross), maybe this helped? Hard to say. Tested resistance at the plug as multiple sources recommend and got 530 ohms resistance (which is within spec). Ideally you use a harmonic balancer to check the CPS, but I don't have one. The symptoms weren't really consistent, because once she was running there were no issues.
                    5. Removed and cleaned starter cables, and alternator cables. No help.
                    6. Checked, and starter was receiving nearly 12v (11.8) on the main post (with big red and black wires) when grounded to the chassis.
                    7. Tried the trick of jumping 14 and 11, but for some reason this didn't work. In retrospect I'm not sure why.
                    8. With car in neutral and key off I held a large screwdriver to the end of the solenoid post on the starter (the smaller one tucked down low with the thin black cable) and touched the main post of the starter (12v) and the starter engaged every time (did this about 5 times to make sure). At this point, I felt that it probably wasn't the starter causing my woes, and I gave a big sigh of relief. The solenoid was NOT getting 12v with the ignition engaged. Starting to hone in on the problem now.
                    9. I only had an hour or so left to work on the car, so I figured I'd inspect the ignition wire. This is the black wire with yellow stripe that runs from the key to the starter. I didn't have time to pull the steering wheel and ignition, but I figured I'd take a peak. Lo and behold the previous owner had bungled the wire right there under the kick panel. It looks like they maybe had an immobilizer installed at some point, and decided they didn't want it anymore and essentially cut it out and twisted the wires back together and covered it with electrical tape. I cut the grossness out and reconnected with a butt connector (I need to soder it appropriately in the future) and BINGO it starts every time.

                    Anyway, I hope that was helpful. Here are some links that I read through which I thought were great.



                    There are several reasons why your E30 BMW won't start. Knowing where to start looking and how to troubleshoot this issue will help you fix the problem faster.


                    I just replaced the engine on my E30-1987 (2.7L). just prior to the transplant, I drove the car into the gagage and unhooked the battery. I finely got



                    Anyway, I hope someone finds this post useful. These electrical gremlins can be annoying, but hang in there!

                    Cheers,
                    Brian



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