Recently picked up a 1987 635csi. Car sat for a number of years. The guy I bought it from got it running. The car started up right away everytime I saw it. Brought it home and started it up myself 3 or 4 times with no issues. Yesterday I tried to start it and all I got was a clicking sound from the gear selection knob. It then started. I went to start it today and after clicking for a few minutes it started. Then I left and came back and tried to start it again and no luck. All I hear is a clicking sound from the same gear selection switch (sport, economy, 321). Everything lights up when I turn the key. But no crank. I have checked the fuses and switched around the relays to no.avail.
Can anyone provide guidance?
Sal 1987 BMW 635csi
Sounds like it could be the "Neutral Safety Switch". Try putting the gearshift in neutral instead of park and wiggle the shift a little to try and find the sweet spot.
If that works, you'll need a new switch. If not, remove the console and jump the switch. If it starts it's the switch.
#12
https://www.realoem.com/bmw/enUS/sho...17#61311215078
ETM
http://wedophones.com/Manuals/BMW/19...g%20Manual.pdf
Bob V
Last edited by 1986series6; 02-17-2020 at 07:32 AM.
Is the starter solenoid engaging as well? Sounds like you are not getting enough power to your starter motor solenoid, or starter for some reason.
Its the "Program Selector Switch" that is making the clicking sound ie the S/E/3-2-1 mode switch. There is a solenoid in this switch that kicks it into "E" setting when you start the car. There's nothing wrong with this switch/solenoid. Its obviously getting the start signal from the start circuit when you are attempting to start, but your starter motor is not getting enough power to crank the engine. I've had exactly the same issue with my '86 auto.
There are many potential culprits for this "no start" situation, especially in an auto. There are about 12 or more joints/connectors/splices/switches/contacts in the start circuit from the battery to the starter solenoid in these cars. BMWs of this era went with modular wiring looms – lots of joints to go bad! Check out section 1240-2 in the ETM for a circuit diagram. The start power circuit goes from the battery to the fuse box, then to the ignition switch, then to the starter relay (through gear selector safety switch to gnd), to a splice point under the dash, back to the fuse box, out of the fuse box again and out to the starter solenoid. A low battery charge, or any dry joints in any of these connections can give you starting problems.
Start by:
-Check that battery is charged
-check and tighten grounds
-Check the starter relay. Its under the left side kick board - should be light blue in colour. Remove and re-insert the relay to check for dry joints
-check wiring/connectors to the starter solenoid
If all of these are good, it could be a bad ignition switch, or dry joints in the main connector out of the fuse box.
You can also check by starting the car by jumpering the leads in the diagnostic connector as this gives a stronger 12V to the solenoid, bypassing all the circuits above. Make sure you are in Park or Neutral!!!!!) . If the car starts OK this way, but not with the ignition switch, this indicates an issue with the switch/relays/wiring. If the car does not start by jumpering the diagnostic connector (with good battery) this may indicate a bad starter solenoid.
....mine ended up being a bad splice joint under the dash that only caused troubles on hot days! I did not even fix it,I just ran a direct wire from the starter relay output directly to the starter solenoid. This bypassed about three joints, and fixed everything.
Hope this helps, let us know how you go.
...another diagnostic tool to consider - I disconnected the starter solenoid, and wired a 55W halogen globe into the start wire. This allowed me to test the start circuit under load (about 5 amps!) by measuring voltages before and after the ignition switch, relays, joints etc. Any significant voltage drop across a joint or device indicates a problem.
1986series6,
Thanks for the resource links. I have tried to wiggle the shifter. As an aside - check out the gear shifter- what is the purpose of the Item #14 in the RealOEM.com link? As you can see its missing. 20200208_100350.jpg20200208_100320.jpg
Tnarkowicz,
Thanks for the advice. I checked the starter relay and it was clicking. I then traced the wire from the soleniod to the battery and found a little fray. But then I wiggled a bunch of wires near the battery and the car started up. What are these wires? Screenshot_20200217-204914_Gallery.jpg 20200215_143612.jpg20200217_163431.jpg
1986series6,
Thanks for the resource links. I have tried to wiggle the shifter. As an aside - check out the gear shifter- what is the purpose of the Item #14 in the RealOEM.com link? As you can see its missing.
#14 is the gear shift lever shaft. It's #12 that's the "SSS". Interrupts circuit so you can't start the car in gear.
The harness has a wire going to the solenoid to engage the starter. The heavy cable from the battery goes to the starter motor not the solenoid.
Those wires you have circled are what BMW calls the "C101" connector. It's the primary connection for the engine wire harness to the fusebox & chassis harness. Earlier cars like mine have a square connector plugged into the side of the fusebox, looks like you have a later version with the big twist-lock barrel connector.
Usually those rubber boots are pulled over the connectors & secured with small zipties. The dangling harness with the relay is usually clipped to the outside of the fuse box block.
Save the manuals!
'08 128i 6MT, '86 635CSi 5MT (B32, Motronic 1.3, WBO2, G265, 18# FW, 3.46 torsen)
Past projects:
'96 318iS, sold 4/23 '90 535iM, RIP 1/23 '90 535iA RIP 6/22 '91 318i, sold 7/19 '97 M3 sedan, sold 11/18 '85 735i, RIP 2/18 '92 325iC, sold 7/16 '91 318iS, sold 6/16 '84 745i, sold 10/14 '82 633CSi, traded 9/12 '90 325i, RIP '87 325 sold '89 525i, traded '87 325iS, RIP
I just re-read this post, did you figure it out? #14 in that diagram is a shift gate pull rod. It's actuated by the shifter grip button, it's just a rod to engage the quadrant gate (#11), keeps the shifter from accidentally getting bumped out of park, selecting reverse at high speed, etc..
You might have a broken shifter grip there too, I'm not too familiar with it, but there should be a collar inside the grip under the shifter button. Check out this eBay listing for details. This aftermarket shift knob isn't original, but might have everything you need to make the car run again.
Last edited by DesktopDave; 02-28-2020 at 09:18 PM. Reason: Links
Save the manuals!
'08 128i 6MT, '86 635CSi 5MT (B32, Motronic 1.3, WBO2, G265, 18# FW, 3.46 torsen)
Past projects:
'96 318iS, sold 4/23 '90 535iM, RIP 1/23 '90 535iA RIP 6/22 '91 318i, sold 7/19 '97 M3 sedan, sold 11/18 '85 735i, RIP 2/18 '92 325iC, sold 7/16 '91 318iS, sold 6/16 '84 745i, sold 10/14 '82 633CSi, traded 9/12 '90 325i, RIP '87 325 sold '89 525i, traded '87 325iS, RIP
Thanks. I ordered a new grip.
....mine ended up being a bad splice joint under the dash that only caused troubles on hot days! I did not even fix it,I just ran a direct wire from the starter relay output directly to the starter solenoid. This bypassed about three joints, and fixed everything.
Hi Tnarkowicz
I also have the same problem . I’ve replaced the ignition switch , the neutral safety switch and the start relay . But still this problem persist. My Battery is new as well .
Can you provide me a diagram or instruction how you did this . I’ve been battling this problem for years . Hoping for your reply and stay safe
Best regard ,
Pgh880
Hi guys ,
Thanks to Tnarkowicz advised to run an additional wire from the start relay (located under the dashboard) directly to the starter solenoid , problem finally solved after 14 years . Still I did not removed the makeshift push start button my tech / mechanic installed back in the day when this problem started .
pgh880
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