e34 Starting Problem ( Strange one )

[Strap]

Hey all,
I am a Neewbee on this forum so first , Hello to all members and i hope i can be a solid contributer to this forum in the future.
Ok now the problem .
every once in a while the car just wont crank, no sound ,no click of the starter , check control shows all ok , and when in the crank position you can see the dash lights dim just a tad as if the car was cranking but its not, it seems to happen after i drive in heavy traffic or very hot days but the temp is normal about halfway all the time. It lasts for between 5 mins to the last time i got stuck 1hr. I even pulled the relays from under the hood to see if one was stuck open or extremly hot but could not find one.
Any info would be great. E34 1995 M50 Right hand drive.

Thanks
Strap

[pundit]

Hey all,
I am a Neewbee on this forum so first , Hello to all members and i hope i can be a solid contributer to this forum in the future.
Ok now the problem .
every once in a while the car just wont crank, no sound ,no click of the starter , check control shows all ok , and when in the crank position you can see the dash lights dim just a tad as if the car was cranking but its not, it seems to happen after i drive in heavy traffic or very hot days but the temp is normal about halfway all the time. It lasts for between 5 mins to the last time i got stuck 1hr. I even pulled the relays from under the hood to see if one was stuck open or extremly hot but could not find one.
Any info would be great. E34 1995 M50 Right hand drive.

Thanks
Strap
First I'd check for dirty battery terminals.
Also check engine and body earth cables.
Other possibilities maybe a sticking starter relay or starter solenoid.

When it does it again have someone try to crank it over while you give the starter motor solenoid a couple of sharp cracks with an appropriate blunt object!

Good Luck! :)

[Strap]

Yep i was thinking about giving it a smack when i was stuck last time :)
. Checked battery terms and main ground points even a meterd resitance test between the battery under the seat and the left front headlight to check for solid ground.all good on the power but i have to find where the starting relays are. anyone no which location?

[emw525E34]

Strap,

Do you know if your key had a chip in it ?. DWS. If it has , this maybe acting up. Cars with DWS security will send and electronic message to the car and if that did not match the expected message. It will show the symptom you had. Everything looks ok will not Click!.
My 95 touring has no chip. Some may have it.

[Strap]

Strap,

Do you know if your key had a chip in it ?. DWS. If it has , this maybe acting up. Cars with DWS security will send and electronic message to the car and if that did not match the expected message. It will show the symptom you had. Everything looks ok will not Click!.
My 95 touring has no chip. Some may have it.


emw525e34,
thanks for that idea, but no chip in mine either. That is the exact symtom im having though. the dealer said the car was fine when they checked it last week then i got stuck 2 hrs later@#$#%# so im hoping to find out whats causing this wierd problem. it only happens so far after im driving in heavy traffic with the a/c going for a long time . but it doesent over heat so im really lost. I can drive all day sit in 95deg( f ) heat in traffic and the car is fine without the air-con on and its fine , run the aircon for 10-15 mins in traffic and after i stop the car park it for awhile it wont crank no sound no clicks , battery is full charge ( i have a digital gauge cluster i added ) and it acts like there is a starter cut-off ? so strage

So im still stumped . :)
Strap

[moots]

emw525e34,
thanks for that idea, but no chip in mine either. That is the exact symtom im having though. the dealer said the car was fine when they checked it last week then i got stuck 2 hrs later@#$#%# so im hoping to find out whats causing this wierd problem. it only happens so far after im driving in heavy traffic with the a/c going for a long time . but it doesent over heat so im really lost. I can drive all day sit in 95deg( f ) heat in traffic and the car is fine without the air-con on and its fine , run the aircon for 10-15 mins in traffic and after i stop the car park it for awhile it wont crank no sound no clicks , battery is full charge ( i have a digital gauge cluster i added ) and it acts like there is a starter cut-off ? so strage

So im still stumped . :)
Strap

The starter solenoid is starved of the juice it needs to crank the engine from the battery.The cause could be an open circuit due to the heat,or hi resistance somwhere.My e30 exhibited this symptom.A parallel solenoid fixed this.Try fitting a new starter solenoid.However,a cheaper way is to run a parallel solenoid.

[SRR2]

Where are you measuring the 12V line? Unless it's directly at the battery, it might be misleading to assume that you're seeing the true value. Your symptoms sound to me like a simple discharged/weak battery. If you're sitting in traffic with the A/C on, you WILL drain the battery. Unless you stick a hydrometer in there and actually measure the SG of the electrolyte, you don't know what's going on.

[oma99]

I had exactly the same symptoms as Strap. Went on for months, gave excuses about hot weather etc. until the misses got cheesed off both with me & Beemer.
I pinpointed it down to the same symptom as if the alarm was on. Not even a click when you turn the key and other times it just goes vroooom with one crank. Decided renew alarm system. Problem solved. A few days later wife complained again. It won't start but makes a rat tat tat tat noise. at least now it's not just nothing like before, suspected battery. Measured the battery and changed it. No problem so far.

Good luck Strap




1989 535i
143K

[Kakaire]

How about checking the fusible links or ckeck Bruno's site on fusible links info.

WWW.BMWE34.NET

[NAT9566]

just wondering.. is it an auto.. have you tried to move the gearstick in front o r about when starting.... it can be that the contact for the safe starting which prevents you starting in other gear positions other than p may be acting up.. you may have to joggle the gearstick around a bit.. whilst starting.

[DanDombrowski]

I know what you're speaking of, but I would think that if that were the case, when he turns the key that the lights wouldn't dim because no new circuit is being created. It definitely could be that, but my first hunch would be that if the neutral safety switch wasn't completing the circuit, the lights wouldn't dim.

[Strap]

Thanks guys ,
I did not even think about the safty switch, and i will change the battery just to be on the safe side. I will let you no if it works out.
Thanks again all
Strap

[BigKriss]

just wondering.. is it an auto.. have you tried to move the gearstick in front o r about when starting.... it can be that the contact for the safe starting which prevents you starting in other gear positions other than p may be acting up.. you may have to joggle the gearstick around a bit.. whilst starting.

the inhibitor switch maybe?

[SLEX Runner]

Try pushing forward the AT lever when in the park position as you try to crank the ignition. Doing so might help "establish" contact. If the car starts while doing this then you're closer to getting your problem solved.

But I also would not rule out the battery.

Goodluck!