starting problems (weird) - BMW Forum

helm · 11-06-2005, 03:31 PM

hi guys i wonder if someone might be able to shed some light on this one?.

when i start the car (320i) and turn it off quicker than 5 mins of running time its a real bugger to get started again , it just keeps turning over and over till the battery finally dies.

if i run the car initially for a longer period of time it always fires up at the turn of the key.

this problem happens if the car is hot or cold as i thought it might be an air flow sensor problem.

any help would be very much appreciated

helm

drz · 11-06-2005, 03:40 PM

Could you just have a bad battery? It takes a decent amount of current to turn the starter motor. If you have a bad battery, it may not be charging very well. As a result, you only get enough juice for one start after running the car for a while. Once you started, the cycle starts all over again. You can also have a faulty alternator. Have both your alternator and you battery checked. In the US auto parts stores will check them for free. If you have to take it to a mechanic where you are located, don't pay too much for this -- it does not involve much work.

helm · 11-06-2005, 04:06 PM

hi drz, yeah thought that myself but hooked my car up to my van on jumper leads and still have the same problem , just keeps turning over and over trying to catch but just doesnt

helm

weird huh??

drz · 11-06-2005, 10:52 PM

I think an alternator that has gone bad can sometimes interfere with the belts turning, and therefore with the whole starting sequence. To tell you the truth, your problem does sound weird.

Dirty Martini · 11-07-2005, 11:35 AM

I had the same symptoms last year with my 325i. I checked for fuel and spark:both O.K. Ended up being a failed crankshaft position sensor. It's a magnetic pickup on the front of the engine that "sees" a notch in your crank pulley and tells the computer when the engine is at #1 top dead center. Without this reference the computer can't properly time fuel and spark so it guesses, sometimes right and sometimes wrong.

This error will show up on diagnostic codes and can be a DIY project. Otherwise it's about $120.00 for the part, $260.00 for the labor.

Get your codes read. If it ends up being this and you want to DIY, let me know and I can walk you through it.

helm · 11-07-2005, 04:06 PM

nice one martini fella,

i'm gonna try and get it to a beemer garage(not main dealer) lol.....and get the codes checked.

at least someone else has had the same symptoms and found a cure. This is driving me mad cos the car runs a straight as a die normally all the time.

cheers mate

lee

Dirty Martini · 11-18-2005, 09:08 PM

Anything new to report? Just wondering how it's going...

PaulsBM · 02-15-2006, 05:33 PM

Thanks for the previous helpfull comments:

I just swapped a 95 engine into my 94 325is. The car cranks but does not turn over, it started ones, sounded great and dies immidiatelly.

Two other concerns I have: The intake manifold from the 94 and 95 are different, I just used my old (the 95 engine has two flapping thingys, mine only came with a single throtle opener).

Also, I failed to connect the ground cable on the engine support.

The engine I purchased has been sitting for a long time, it was also from a wrecked car, so I'm thinking the sensor could be it, checked everything as well, spark, air, fuel.

Any other advise your Majesty?

used:

PaulsBM · 02-20-2006, 05:21 PM

Is there any way to check the crankshaft position sensor? I doubt its an ECU problem, I’m almost 100 % sure that 94 engines and 95 engines had the same ECU (both 325is engines). I have not grounded the sh*t, I will have to do that next,

thanks for your feedback Beemer freaks!

Dirty Martini · 02-21-2006, 10:18 AM

The inexpensive (read "free") way is, as is often the case, a major pain. It involves finding the end of the wire that comes from the sensor which is burried deep on the driver's side of the engine underneath the intake, etc., disconnecting it, and reading resistance across the two leads with a multimeter. If this is the way you want to go, I can get you the expected good readings, I'll have to look them up.

I gave up on that approach simply because I needed the car back on the road and there was alot of stuff that needed to be moved/removed in order to get to both the sensor on the front of the engine and the end of the wire. It'll cost ya', but that failure as well as many others will show up if you get codes read. You can buy a code reader and have it forever whenever you need it, or you can pay someone (NOT THE DEALER, PLEEZZ) to read them for you.

tomctx · 02-21-2006, 05:04 PM

Quote:

Originally Posted by PaulsBM

Is there any way to check the crankshaft position sensor? I doubt its an ECU problem, I’m almost 100 % sure that 94 engines and 95 engines had the same ECU (both 325is engines). I have not grounded the sh*t, I will have to do that next,

thanks for your feedback Beemer freaks!

They had the same ECU part number, but difference in the programs after 11/94.