Help!

[Flamin'Cow]

Dear All,

okay, this is really starting to piss me off now...

When I bought my car it had a starting issue. It started first time on the key after having sat for a couple of months. Drove about 1 mile to a petrol station and then it would'nt start. Tries jump starting it, but no joy - eventually got started thanks to some kind people at the service station giving me a push.

It ran fine after that for 3 or 4 weeks, then, all of a sudden - it wouldn't start.

No cranking of the motor, no 'click' from the solenoid - nothing...just the sound of the injectors....

So, out came the starter motor (which is a PAIN to remove). All the contacts looked good inside, teeth are fine. Gave it a clean and a greasing and took the time to replace the solenoid with that of my old BMW 320i (which never had any starting issues). - Car then started first time - no problems.

That was just over a week ago and today I went shopping, successfully started/stopped the car about 4 or 5 times and then 'nothing' - same deal all over, no 'click' - nothing.

Gave the starter motor/solenoid several 'taps' - still nothing.

Tried push-starting the car - its kinda started, but sounded like it was running on only 1 cylinder and wouldnt 'catch' (of you know what I mean).

Tried again, this time attempting to bump-start at the same time as turning the key and the starter motor was turning over, but it wouldnt 'catch'. Rolled to a stop and tried the key again and 'bruuumm' started no worries.

Drove home, turned it off, tried the starter again - no worries. Drove to a mates house started/stopped no problem. Will probably start now if I go out to it, but one day, perhaps tomorrow - it wont start.

WHAT THE HELL IS GOING ON?????

Also, there is a stray wire that I think was originally attached to the 'top' male connector on the starter. However, the car still starts with/without this wire connected - so it can't be that important - can it?

HELP - I'm going mad here!

Kind regards

Flamin'Cow

P.S. - Car is a 1989 535I SE.

[3rdE34]

Hi Flamin Cow, i may be way off the mark ..but i would check my spark plugs and you didnt get a dose of bad fuel did you? (i am only trying to help & keep in mind it is 4.00am here now)

[632 Regal]

sounds like a battery issue. the alternator can have bad diodes and drain the battery when it sits.

[Flamin'Cow]

Hmm all interesting points RE; the spark plugs, fuel, battery etc.

Tried a different battery, made no difference. When the car does start, there is no 'slow cranking' that you would expect from a dead cell. All the electrolite levels are fine. Alternator is charging as it should (no dimming of headlights in idle compared to higher RPM).

Did use 98 Ron 'Super' unleaded when I first got the car, have been running on 95 ever since (its cheaper), from the same garage as always. Put a couple of bottles of injector cleaner through the system as was a bit jerky when I first got it. (like Kangaroo Juice [someone who does not know how to control a clutch pedal]).

Changed spark-plugs when I first got the car, set the gap as per the instructions on this website. (i.e slightly larger than normal).

These dont explain the problem tho...when she starts, she starts fine - runs fine. Then 'out of the blue' - she wont start. No crank of the starter motor, no 'click' from the solenoid - nothing. I think the problem must lie BEFORE the starter motor/solenoid assembly. Its defo an electrical problem - but what????

[DaveVoorhis]

It might be a bad key switch, dodgy solenoid (even though you replaced it), bad wiring, intermittent fuse F17, defective jumper plug in the fuse box, etc. Next time it doesn't start, get out a voltmeter and start tracing -- there are no shortcuts to fixing this kind of intermittent problem. The top conductor on the solenoid is used to advise the OBC, general module, etc., that the starter is being activated, but if you supply battery + to it you can spin the starter without engaging the solenoid.

[Flamin'Cow]

Thanks, where is fuse F17? is it that one on a red lead running from the battery under the rear seat?

[DaveVoorhis]

F17 is in the fuse box, but I was wrong about it -- had a brain fart and mis-read the wiring diagram. If it's a fuse, it would be the main fusible link connected to the battery +ve terminal. However, your symptoms make me think wiring, key switch, or solenoid. Next time it fails to start, check for voltage at the lower terminal of the starter solenoid. If you've got voltage, it's almost certainly the solenoid. If you've got no voltage, it's wiring or key switch.