car won't start - won't crank...need ideas

[slimline]

My daughters 1997 318 automatic suddenly won't start. I've meticulously maintained the car and the engine/mechanicals are kept in pristine shape.

- The battery is less than 3 months old and has worked perfectly
- The car runs perfectly
- I only use BMW OEM parts
- Nothing has been touched in months

All of a sudden it won't start, no cranking, not a sound. I can usually get it started by disconnecting the positive battery cable for 5 minutes and sometimes I have to tap on the starter. Then the car cranks and starts perfectly. During cranking it's obvious that the battery is very strong.

It seems like the starter solenoid could be the culprit or possibly the immobilizer...?

I've already checked the grounds and all fuses - they're fine...any ideas?

[aceyx]

You can troubleshoot a bad starter solenoid by shorting the terminals with a screwdriver, if you can get a hand down there.

When it is the immobilizer, the engine will click but not fire.

[tiFreak]

I've heard that if you start the ti, move it a short distance, shut it off and let it sit, it won't start the next time you try to start it, I can't remember what the symptoms are so that might not be your problem

[sam316i]

If you have to tap on the starter its more than likley to be that, i beleive the contacts on the comutator get worn or dirty over time. If you replace the starter be sure to get the one with the threads in the starter motor rather than the one that uses nuts on the back as these can be a real pain.

[Laxpunk2006]

Originally Posted by tiFreak

I've heard that if you start the ti, move it a short distance, shut it off and let it sit, it won't start the next time you try to start it, I can't remember what the symptoms are so that might not be your problem

Do you have any more information or a source for this?

[vjmvjmvjm]

Originally Posted by Laxpunk2006

Do you have any more information or a source for this?

The "car wash" problem occurs when you start your car and move it a short distance. Like after washing your car. When you try to start it again, it cranks, but doesn't start easily. Since the car doesn't crank, that's not the problem.

If you have the "car wash" problem, just floor the accelerator and crank until the car starts. It will run a little rough at first, just like a flooded engine.

Vic