Emilios
08-09-2010, 01:06 AM
Dead starter diagnosis
Symptoms: When turning key absolutely nothing happens, no crank, no sounds, no dimming of lights, nothing.
Tools:
-Multimeter
-If you have Long wheel base model then more effort is involved to check battery under rear seats. http://www.bimmerboard.com/forums/posts/22903
To narrow the issue down to the starter just follow the path of electricity from battery positive to negative.
Check for cracked fusible links, fuses, loose wires, and grounds.
Then check K1 Starter Relay and voltage being supplied to starter solenoid.
To do the above I thank E32FAN for the help he gave me.
E32FAN, "Print 0680-23, 1240-00,01, 7100-01,02 at http://www.e38.org/e32/e32_91_etm.pdf
Locate K1 Starter Relay (7100-01 Fig 1). With key in RUN position (but not START), move shifter repeatedly between N and D and listen for the (soft) clicking of K1. If K1 clicks then shifter S3 is doing its job and powering the "R" arrow on the schematic.
Now unscrew the D100 diagnostic connector cover (7100-02 Fig 1) and set it aside. [Don't worry about the 4 pins in the cover - they just short pins 14-15 and 19-20 to quiet the diagnostic datalink.] Locate pin 11 (using 0680-23). Notice that the "Not Used" pins have no contact inserted. This gives us confidence that we are counting the pins correctly. Put your voltmeter + probe into D100 pin 11 and - probe into pin 19 GND. This is a convenient tap of the voltage to the starter solenoid.
Turn the key to START and see if you get voltage at D100 pin 11. If so, then the ignition switch and starter relay are healthy. Listen for the snap of the starter solenoid (not relay) inside the starter motor assy. If the solenoid is clicking but the starter motor is not cranking, then the starter motor has a bad commutator segment (so it can produce no torque) and must be rebuilt."
If you find that the K1 Starter Relay may be the cause of your problems you can bridge the pins to bypass it completely for a more definitive test, but be warned as you can then start the engine while being in gear if you forget.
http://www.bimmerboard.com/forums/posts/470405/
If, like me, your relay is fine and you do get voltage to the starter (I had 11.8 Volts) then it can be well determined you have a bad starter and replacement is necessary.
Starter removal
Tools:
-17,13,12,10mm wrenches / sockets
-socket wrench and extensions (preferably 1/2 drive)
-breaker bar if needed
-Disconnect battery with 13mm
-Remove two plastic 10mm nuts holding coolant expansion tank to firewall and the metal rail that covers the two thick bundle of wires across firewall.
Use any piece of cord or string or twine to hold the tank and wires up and away from the firewall. I tied it to the hood mount frame in the front of the engine bay.
-Unplug O2 sensor wire and (I think) the evap purge valve wire runs down there. Just set aside out of the way.
If you feel gives you more room, unplug vacuum line from intake manifold to brake booster.
-disconnect wires to starter solenoid. Positive terminal is 13mm, ground is 12mm, and ignition switch is 10mm. Mark wires if you feel you might mix them up and place nuts back where they came right away so you don't loose any.
Now the fun part.
The starter itself is held in place by two 17mm bolts to the block.
The bottom one i found easiest to reach with a socket wrench and extensions. You can get it slowly click by click as there isn't much room for wrenching. But it is the only way.
(You can see my coolant hoses up here as I deleted a/c and heat, but I did the starter replacement while the heater was still in and hoses in the way. Just took the pictures later.)
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00465.jpg
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00464.jpg
The second bolt can be reached through the top along the firewall reaching down. Use the closed end with the bend of the wrench facing the rear of the car and use your other hand to keep it in place on the bolt.
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00467.jpg
For extra leverage use another large sized wrench and lock them together. (Zoom in for better view)
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00466.jpg
Then just wiggle it out any way you can. and try not to drop it, it's heavy.
Starter Installation
If you have just bought a replacement then installation is reverse.
Starter Rebuild
But if you are like me and want to rebuild it follow these links.
http://www.bimmerboard.com/forums/posts/462336/
http://twrite.org/shogunnew/fixes/startermotor.html#1988_750_starter
There are many different versions of these starters as I found out, but it is all the same basic concepts. Shogun's starter had plastic planetary gear housing, rv8flyboy's had four planetary gears whereas I had 3, ect ect.
Some tips to go along with there write-ups:
-Putting the commutator brushes back in place it is easiest to use zip ties to hold three of them in place and put them back in one by one and then snipping off the ties.
-Use an ohm meter to test the resistances from each wire before the brush to the commutator to check for minimal resistance between the two. Got an average of 60-70 Ohms.
-To re-use the metal c-ring clip at the end of the main shaft to stop the bendix gear, use a torch to heat it up and make it easier to get it back in place. (That was a hard step and took awhile)
-On my starter I found the problem to be a bent metal plate behind the plastic carrier for the planetary gears. This ground off the coating on the wires behind that and grounded out the whole starter. Tried over and over to repair but had to buy a replacement in the end...
-In my case, the bendix gear would be pushed out to contact the flywheel gear, but it would not spin. This indicates no electricity flowing from solenoid to motor or grounding out somewhere inside the assembly.
For bench testing a starter follow this link.
http://www.misterfixit.com/starttst.htm
Price:
If you were able to fix your starter yourself congratulations! You just saved yourself $120. Take your old starter where ever you go to buy a new one and you get a core charge price return, $60 off the original $180 price.
Or take the bad starter to a repair shop if you are lucky enough to have one and I am sure that would be much cheaper.
Time:
After you take the starter on and off 4 times (Like I have...) you get it down pretty easy and it takes no more than 12 minuets for each removal and re-installation. (Yes I timed myself hah)
As for trying to rebuild the starter, that will take up a few of your hours, or a few days if your like me and don't want to spend a dime on repairs so you try to disassemble / think you fixed the problem / re-assemble / bench test only for it not to work well over 8 times... ughhhh
PM me or comment in this thread (Read this too if you want more info on my experience) if you have any questions of comments.
http://forums.bimmerforums.com/forum/showthread.php?t=1482282&
Edit: additional comment by Neel dated 07/18/2016:
As a temp until my m30 starter is rebuilt, I just now finished install of an M10 starter into my 1990 e34 M30B35. It has started my car several times now. I knew M10 owners have subbed the M30 starter in so i gave it a try because I was in a pinch. It worked.
Symptoms: When turning key absolutely nothing happens, no crank, no sounds, no dimming of lights, nothing.
Tools:
-Multimeter
-If you have Long wheel base model then more effort is involved to check battery under rear seats. http://www.bimmerboard.com/forums/posts/22903
To narrow the issue down to the starter just follow the path of electricity from battery positive to negative.
Check for cracked fusible links, fuses, loose wires, and grounds.
Then check K1 Starter Relay and voltage being supplied to starter solenoid.
To do the above I thank E32FAN for the help he gave me.
E32FAN, "Print 0680-23, 1240-00,01, 7100-01,02 at http://www.e38.org/e32/e32_91_etm.pdf
Locate K1 Starter Relay (7100-01 Fig 1). With key in RUN position (but not START), move shifter repeatedly between N and D and listen for the (soft) clicking of K1. If K1 clicks then shifter S3 is doing its job and powering the "R" arrow on the schematic.
Now unscrew the D100 diagnostic connector cover (7100-02 Fig 1) and set it aside. [Don't worry about the 4 pins in the cover - they just short pins 14-15 and 19-20 to quiet the diagnostic datalink.] Locate pin 11 (using 0680-23). Notice that the "Not Used" pins have no contact inserted. This gives us confidence that we are counting the pins correctly. Put your voltmeter + probe into D100 pin 11 and - probe into pin 19 GND. This is a convenient tap of the voltage to the starter solenoid.
Turn the key to START and see if you get voltage at D100 pin 11. If so, then the ignition switch and starter relay are healthy. Listen for the snap of the starter solenoid (not relay) inside the starter motor assy. If the solenoid is clicking but the starter motor is not cranking, then the starter motor has a bad commutator segment (so it can produce no torque) and must be rebuilt."
If you find that the K1 Starter Relay may be the cause of your problems you can bridge the pins to bypass it completely for a more definitive test, but be warned as you can then start the engine while being in gear if you forget.
http://www.bimmerboard.com/forums/posts/470405/
If, like me, your relay is fine and you do get voltage to the starter (I had 11.8 Volts) then it can be well determined you have a bad starter and replacement is necessary.
Starter removal
Tools:
-17,13,12,10mm wrenches / sockets
-socket wrench and extensions (preferably 1/2 drive)
-breaker bar if needed
-Disconnect battery with 13mm
-Remove two plastic 10mm nuts holding coolant expansion tank to firewall and the metal rail that covers the two thick bundle of wires across firewall.
Use any piece of cord or string or twine to hold the tank and wires up and away from the firewall. I tied it to the hood mount frame in the front of the engine bay.
-Unplug O2 sensor wire and (I think) the evap purge valve wire runs down there. Just set aside out of the way.
If you feel gives you more room, unplug vacuum line from intake manifold to brake booster.
-disconnect wires to starter solenoid. Positive terminal is 13mm, ground is 12mm, and ignition switch is 10mm. Mark wires if you feel you might mix them up and place nuts back where they came right away so you don't loose any.
Now the fun part.
The starter itself is held in place by two 17mm bolts to the block.
The bottom one i found easiest to reach with a socket wrench and extensions. You can get it slowly click by click as there isn't much room for wrenching. But it is the only way.
(You can see my coolant hoses up here as I deleted a/c and heat, but I did the starter replacement while the heater was still in and hoses in the way. Just took the pictures later.)
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00465.jpg
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00464.jpg
The second bolt can be reached through the top along the firewall reaching down. Use the closed end with the bend of the wrench facing the rear of the car and use your other hand to keep it in place on the bolt.
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00467.jpg
For extra leverage use another large sized wrench and lock them together. (Zoom in for better view)
http://i973.photobucket.com/albums/ae219/Emilios01/DSC00466.jpg
Then just wiggle it out any way you can. and try not to drop it, it's heavy.
Starter Installation
If you have just bought a replacement then installation is reverse.
Starter Rebuild
But if you are like me and want to rebuild it follow these links.
http://www.bimmerboard.com/forums/posts/462336/
http://twrite.org/shogunnew/fixes/startermotor.html#1988_750_starter
There are many different versions of these starters as I found out, but it is all the same basic concepts. Shogun's starter had plastic planetary gear housing, rv8flyboy's had four planetary gears whereas I had 3, ect ect.
Some tips to go along with there write-ups:
-Putting the commutator brushes back in place it is easiest to use zip ties to hold three of them in place and put them back in one by one and then snipping off the ties.
-Use an ohm meter to test the resistances from each wire before the brush to the commutator to check for minimal resistance between the two. Got an average of 60-70 Ohms.
-To re-use the metal c-ring clip at the end of the main shaft to stop the bendix gear, use a torch to heat it up and make it easier to get it back in place. (That was a hard step and took awhile)
-On my starter I found the problem to be a bent metal plate behind the plastic carrier for the planetary gears. This ground off the coating on the wires behind that and grounded out the whole starter. Tried over and over to repair but had to buy a replacement in the end...
-In my case, the bendix gear would be pushed out to contact the flywheel gear, but it would not spin. This indicates no electricity flowing from solenoid to motor or grounding out somewhere inside the assembly.
For bench testing a starter follow this link.
http://www.misterfixit.com/starttst.htm
Price:
If you were able to fix your starter yourself congratulations! You just saved yourself $120. Take your old starter where ever you go to buy a new one and you get a core charge price return, $60 off the original $180 price.
Or take the bad starter to a repair shop if you are lucky enough to have one and I am sure that would be much cheaper.
Time:
After you take the starter on and off 4 times (Like I have...) you get it down pretty easy and it takes no more than 12 minuets for each removal and re-installation. (Yes I timed myself hah)
As for trying to rebuild the starter, that will take up a few of your hours, or a few days if your like me and don't want to spend a dime on repairs so you try to disassemble / think you fixed the problem / re-assemble / bench test only for it not to work well over 8 times... ughhhh
PM me or comment in this thread (Read this too if you want more info on my experience) if you have any questions of comments.
http://forums.bimmerforums.com/forum/showthread.php?t=1482282&
Edit: additional comment by Neel dated 07/18/2016:
As a temp until my m30 starter is rebuilt, I just now finished install of an M10 starter into my 1990 e34 M30B35. It has started my car several times now. I knew M10 owners have subbed the M30 starter in so i gave it a try because I was in a pinch. It worked.