318ti won't start- bmw doesn't know why

[bigbooly]

I have a 95 318 with 80k miles. It has a new battery and everything works perfectly. In the last six months it has begun to not start on occation. Typically if I wait 20-30 minutes, it will start right up. This morning was a perfect example. I turned the ignition, all the instrument lights go on, the radio is on, sunroof works, I stepped outside and the headlights were bright, but there is not even a click- nothing engine wise happens. I hooked up jumper cables- nothing, no click or anything. I rolled it down the driveway (it is manuel) and started it that way. I immediately drove it back up the driveway into the garage, turned it off and proceeded to start the car successfully. I successfully turned off and on the car 3 or 4 times in a row then left for work.
This scenario has happed once every three weeks exactly like I've described. Half the time this has happed after I've left the car sit for 8 hour or so, but the other half of the time the car will sit for as little as 30 min and it will do the same thing.
I have talked to the BMW dealer mechanic over the phone and he thought it was a battery problem, but after I got the new battery last month, I still have the same problem.
If any of you know about this and could give me some help on what you think it is- I'd really appreciate it!! Thanks!

[dodj]

i used to have the EXACT same problem when i first got my car. it drove me insane to the point that i was going to sell it.

All electrics work but the car wont start, Occasionally you may also see strange readings in the odometer, garbled numbers etc, but not always... It would only happen once every week or so and would always fix itself after 20-30 minutes. It also triggers the air bag light am i right?

I took it to the BMW dealer numerous times they checked the whole wiring harness everything ok, they eventually told me they duplicated the problem by playing with the wires connected to the battery, they cleaned and tightened and told me all was ok.

A couple weeks later same problem happened, and continued to happen as usual.

Now hear is the bit you want to hear. A month later i got a new stereo and sub installed. The shop installed the stereo which also needed power cables connected to the battery.

A couple months go by, and I haven't had the problem of the car not starting, BUT occasionaly the car stereo would die and not come on for 30 or so minutes....

This continued every now and then for a while, and i was happy since it was my stereo that would cut out instead of my car not starting. A few months go by and now neither of them cut out. I have no problems now for almost a year.

My car has not had a starting problem since the day my car stereo was installed. Which leads me to believe that it was somehow related to the battery connections, like BMW originally suggested but didn't fix.

Hope this all makes sense, the problem you describe is exactly what i had and drove me insane, so check the battery connections!!!!

[frank]

I had a simliar problem where it was the key. Did you try a different key or check your clutch if you have a standard trans. Ther is a mico switch on the clutch pedal.

[Ed montocchio]

What about the Crankshaft position/rpm Sensor - If the engine control module (ECM) does not receive a crankshaft position signal during cracking, the engine will not start - just a thought...

[L84THSKY]

The clutch switch was the first thing I thought of.

Originally Posted by frank

I had a simliar problem where it was the key. Did you try a different key or check your clutch if you have a standard trans. Ther is a mico switch on the clutch pedal.

[bigbooly]

A month later i got a new stereo and sub installed. The shop installed the stereo which also needed power cables connected to the battery...
My car has not had a starting problem since the day my car stereo was installed. Which leads me to believe that it was somehow related to the battery connections, like BMW originally suggested but didn't fix.

Hope this all makes sense, the problem you describe is exactly what i had and drove me insane, so check the battery connections!!!![/QUOTE]

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thanks for the advice. Strangely enough I did get a new stereo put in last week, but unfortunately in my case it didn't solve the problem. I don't know what to do on the battery connections- because the battery is only a month old everything is clean and looks beautiful.

[bigbooly]

Originally Posted by frank

I had a simliar problem where it was the key. Did you try a different key or check your clutch if you have a standard trans. Ther is a mico switch on the clutch pedal.

******************************
I have never heard of using a different key- I'll try this! Thanks! A "micro switch on the clutch pedal"? What is this? Where is it, or how do I check it? I went out and looked at my clutch, I didn't see anything that would obviously look like that, but I could be wrong.

[prd318ownr]

Its the starter!!!!!!!!!! Ill leave it at that... Just got done asking all the same questions.... 580$ later my starter was installed and my ignition rewired to bypass the clutch button and back to where theres no push start...........

Good luck

[dodj]

Not sure if you are still around but my car used to have this problem but went away for over a year.

The problem came back a month ago. My car has been to an auto electrician and they found a loose earth wire under the passenger side carpet.

Just thought id post since ive heard a few ppl have this problem and i know how frustratiing it is. I am almost positive it would be a similair problem in other cases

[cossieturbo]

Well looks like everyone is on the right track. I would 1st label the Starter, maybe freezing Starter shaft. It's rare, but the Starter Relay could be having issues. A bad Battery connection and or ground is quite possible. I don't know of any 1995s with a Clutch Start Inhibitor (Clutch switch). These were in later cars. Hope this helps.

cossieturbo

[biorjin]

Very likely, the starter or ignition wire set is bad

[T-Huss]

i had the same problem all lights working but no click or anything.and it ended up being that the brake light wire shorted out my ignition fuse costed $200 bmw dealer,they went through the entire electrical system. i couldn't find out what happened and i was so pissed. hope you find out what it was

[bigbooly]

Short answer- it was the starter. I tried the spare key idea- didn't work. I had the ignition and tumbler replaced, including the EWS ring on the outside of the tumbler that communicates with the standard bmw anti-theft system that is on every 318ti (bmw says these go bad with some frequency) - this wasn't it. #$#@@#!

Next BMW hooked a wire on the starter and said that the next time it acted up I should put a tester light on it (which would tell if power is getting to the starter). When it acted up, I put the tester light's needle into the wire like they told me (mistake- I should have stripped the wire bare and wrapped the wire around the tester light) - the tester read that there was no power to the starter.
Long story short- after weeks of testing BMW got it to act up and they wrapped a wire around tester needle and it showed that power WAS getting to the starter. Bingo- bad starter. Many @##$$$$ later the starter is new and it has been working great for months.

Lesson learned:
If I had the problem again I would do the following three things in this order:
a) buy a $4 tester light at the car parts store. Hook a wire to the starter and the next time it acts up, pull out the tester light and see if power is getting to the starter. If so- replace starter. If not- go to b.
b) Have BMW replace the EWS ring that is arround the ignition tumbler- this is the standard anti-theft system that is on every 318ti - bmw says it often goes bad- it will cost $150-200 to replace.
c) Replace the ignition and tumbler- especially if your key has spun 360 degrees in the ignition with some frequency. This wears down the ignition system and eventually will require your ignition to be replaced anyway.

Good luck and thanks for all the help!