2000 BMW E39 523i won't start - M52TU engine
Discussion
Problem now solved thanks to lufbramatt
The car was running fine yesterday, the O/H moved it out of the driveway on to the road, and then back into the driveway later in the day.
This morning, the engine just spins but it won't start.
I don't have a diagnostic tool for this car (it's the old round type under the bonnet) so can't get any diagnostics myself.
Would a failed camshaft sensor (or even crank sensor) prevent the engine from starting?
Is there anybody nearby Leeds (LS20) that could run a diagnostic for me in my driveway?
I don't hear any untoward noises that would indicate a broken cam chain, but the engine does sound to be spinning quite freely as well, but it may just be normal, as it's never failed to start before.
I've checked several fuses but can't find any issues there either.
Help!
Edited by TonyRPH on Tuesday 9th April 15:42
I think this is a common issue on these 6cyl BMWs... I've done the same thing to my 530i. Something to do with them dumping loads of fuel through the cats on initial start up to get them up to temp quicker. As a result if you run them for a very short period they either foul the plugs or flood IIRC.
If I need to move the car off the drive I always drive it round the block or let it idle for a couple of minutes before turning it off.
Have you tried turning it over for 20 secs or so with your foot right down on the throttle pedal to clear out any fuel from the bores?
If I need to move the car off the drive I always drive it round the block or let it idle for a couple of minutes before turning it off.
Have you tried turning it over for 20 secs or so with your foot right down on the throttle pedal to clear out any fuel from the bores?
Edited by lufbramatt on Tuesday 9th April 14:46
Leave it a good few hours, ideally overnight, for a proper normal cold start. If same symptoms it does sound like it needs an in depth look, but sounds like its a fully flooded engine.
Can try (as already said by other poster) holding accelerator fully down (don't let go of it, or pump it ) and try that. Might need a few bursts of 10 to 20 secs on the starter without releasing that pedal, but allow a good minute in between each attempt to allow the starter to cool and the battery some respite/recovery time. If it catches, allow it to fully start and begin to rev before letting go of that pedal. The last thing you want to do is flood it even more.
That all assumes it is turning over as normal. If you suspect, for any reason, that the chain has untensioned or slipped, don't even attempt to start it, but get it checked out first.
Can try (as already said by other poster) holding accelerator fully down (don't let go of it, or pump it ) and try that. Might need a few bursts of 10 to 20 secs on the starter without releasing that pedal, but allow a good minute in between each attempt to allow the starter to cool and the battery some respite/recovery time. If it catches, allow it to fully start and begin to rev before letting go of that pedal. The last thing you want to do is flood it even more.
That all assumes it is turning over as normal. If you suspect, for any reason, that the chain has untensioned or slipped, don't even attempt to start it, but get it checked out first.
Guyinacar85 said:
No a failed cam sensor or crank would not have anything to do with the car not starting. Is the car in question a basic 5 series or M5? It is most likely the starter motor has packed in that's why it won't start.
If the chain has slipped, setting the sensors in wrong positions, or the sensors themselves failed, then yes they could cause these symptoms, but unusual to be a total sudden failure (but possible)If the starter is turning at its normal speed, you can safely ignore that as the cause.
lufbramatt said:
I think this is a common issue on these 6cyl BMWs... I've done the same thing to my 530i. Something to do with them dumping loads of fuel through the cats on initial start up to get them up to temp quicker. As a result if you run them for a very short period they either foul the plugs or flood IIRC.
If I need to move the car off the drive I always drive it round the block or let it idle for a couple of minutes before turning it off.
Have you tried turning it over for 20 secs or so with your foot right down on the throttle pedal to clear out any fuel from the bores?
This man wins!!If I need to move the car off the drive I always drive it round the block or let it idle for a couple of minutes before turning it off.
Have you tried turning it over for 20 secs or so with your foot right down on the throttle pedal to clear out any fuel from the bores?
Edited by lufbramatt on Tuesday 9th April 14:46
That was indeed the issue - I went and sat with foot flat down and kept on cranking, and eventually she burst into life.
I had a similar issue a few years back with my E34 520i, but it did start after a few turns.
I've told my O/H many times not to just move the car in and out but at the very least to go around the block both times.
Oh well - problem now solved - thanks to all who posted.
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