Help please. My 540i wont start.

[besar]

Ok I am totally confused and was wondering if you guys could give me a few pointers.

Yesterday I was parking my car (a E34 540i Manual) when i reversed into a bollard, D'oh! Fortunately it hit the tow bar and did no dmage but it did give the car a bit of a jolt. Anway everything seemd ok and I continued to park the car. Anway when I came back to the car it wouldn't start. Everything seemed to work OK, the ignition came on but the starter just wouldn't crank. When trying to start all that I got was a relay click coming from the passenger footwell. There was no click or noise coming form the starter motor and no dimming of the lights.

The only other thing I noticed at this point was that the central locking stopped working properly. On the drivers door the lock wouldn't work the central locking. On the passenger side if you locked the door the central locking would lock and then instantly unlock again. However if you locked it again it would lock and stay locked.

Anyway I mangaged to get a push start and the engine started and ran fine. When I got home I checked all the fuses and gave all the relays a wiggle and all seemed fine but it still wouldn't crank.

This morning it all got even stranger. I wondered if the problem might have been cause by the inertia switch being triggered so I tried disconnecting it. Then when I tried cranking I got a louder click that sounded like the starter solenoid firing, but still no cranking. I then reconected the inertia switch and it made no difference. It was still this load clicking from the starter solenoid. It was at this point I notice smoke coming from the engine. This turned out to be the insultation from the oil level sensor ground wire burning off. This was some how being sorted out when trying to start.

Now I am stuck, and haven't got a clue what is going on, so any help would be appreciated.

Could it be a starter motor problem, or is it an electrical issue? Where is the starter motor located? How easy is it to get at, I can't even see it at the moment?

Any suggestions gratefully accepted.

Cheers,

Chris.

[Ferret]

It was at this point I notice smoke coming from the engine. This turned out to be the insultation from the oil level sensor ground wire burning off. This was some how being sorted out when trying to start.

By the sounds of it you've lost your engine block to car body earth lead... try getting a jump lead and connecting it from the engine block to the car body (large guage proper car jump lead please) and then try starting it again - see what happens.

[timandbim]

is it possible your battery terminals are loose or corroded and lost some contact when it got jolted? i once forgot to tighten my battery terminals after doing some work and had the same condition (seems fine just doesn't start).

[whiskychaser]

Probably is - but as you have a tow bar I assume you have the wiring sockets too? Any change you crunched one? I know it should only handle lighting but stranger things have happened

[besar]

Ferret you are a bl**dy genious I found an old earth strap off another car and bolted it between a strut top and cam cover fixing and low and behold it started!!! I haven't a clue why the old earth lead stopped working. Does anybody happen to know where the earth lead is located on these beasts??

The central locking is still not working properly so I'll have to look into that.

I had previously checked the fueses under the rear seat, which I think do the cenrtral locking but I'll have to go back and double check them.

Thanks for your help all.

[glen-sj]

When you checked all the fuses and relays, did you include the rear fuse box under the rear seat? I had a similar case of no start, no central locking. It turned out two of the 7.5 amp fuses in the rear fuse box were blown due to broken wires shorting out within the wiring harness inside the trunk.