Dead BMW, suggestions?

Clarkey · 29 May 2010 at 16:15

So, the e46 320d won't start today. Cranks over and over forever but won't fire at all.

Any suggestions? Took it to the garage yesterday to have its MOT and had the oil topped up, it passed with flying colours and drove fine for the rest of the day. Now it's totally dead.

I've currently got the battery off in an effort to reset the ECU in the hope that it just might make a difference. I guess I'll take the cover off and check all the connections are on the engine.

Garage is closed until Tuesday now, unfortunate timing :/

spirits247 · 29 May 2010 at 16:20

That is too much of a coincidence that it has gone dead after being to the garage for an MOT. Sounds like they've not re-connected something properly.

DRZ · 29 May 2010 at 16:20

Can you smell fuel out the back when you are cranking?

spirits247 said:
That is too much of a coincidence that it has gone dead after being to the garage for an MOT. Sounds like they've not re-connected something properly.

MOT Testers shouldn't be touching anything mechanical to do with the car at all. They can't even take a wheel off...

Lashout_UK · 29 May 2010 at 16:29

Be a sensor or a fuelling issue, maybe cam position sensor or fuel pump has packed up.

Checked the fuses?

spirits247 · 29 May 2010 at 16:31

DRZ said:
Can you smell fuel out the back when you are cranking?

MOT Testers shouldn't be touching anything mechanical to do with the car at all. They can't even take a wheel off...

Fair enough - it just seems strange. But life does do this sometimes.

Locky · 29 May 2010 at 16:37

Lashout_UK said:
Be a sensor or a fuelling issue, maybe cam position sensor or fuel pump has packed up.

This tbh, fuel pumps just tend to let go without warning and usualy after you try to start it after it's been used.

Django x2 · 29 May 2010 at 17:22

Shove a good squirt of Easy Start down the intake (EGR valve best otherwise it won't reach the cylinders) whilst someone turns the key. If it starts its a fueling issue. You can't "reset" the ECU how you are suggesting, it just won't happen. The last known state is held in an EEPROM and that would need to be flashed to be reset.

Known issues are the fuel pump (High Pressure and Low Pressue), or Cam / Crank sensors can also cover the symptoms you describe.

So, if it doesn't start with Easy Start, you should be looking at the Cam / Crank sensors

Clarkey · 29 May 2010 at 17:23

Thanks for the input guys. I got it going in the end, as a last resort I tried jumping it and it fired right up. This seems very strange because there was no sign that the battery was low, was cranking over at a healthy speed. It's a mystery to me, but I guess a new battery wouldn't go a miss.

Lashout_UK · 29 May 2010 at 17:49

Odd that! We had a similar occurance on my dad's Merc; but it wouldn't turn over - the battery would randomly drop a cell so everything would come up as usual and everything worked spot on but it just wouldn't go. After a while it'd just start, no issues...

Funny old things!

GeX · 29 May 2010 at 17:52

is the diesel emissions test still bounce it off the limiter and look for smoke? maybe something was on its last legs and is dead now

Clarkey · 29 May 2010 at 18:04

Pretty much yes, although it won't rev all the way up while stationary in neutral. I took it round the block and gave it some welly and it seems to run totally fine.

The_Dark_Side · 29 May 2010 at 19:08

Clarkey said:
Pretty much yes, although it won't rev all the way up while stationary in neutral. I took it round the block and gave it some welly and it seems to run totally fine.

So it revs normally when driving, but not when stationary and in neutral?
At first I thought the ECU had gone into get home mode, but if it performs as normal when driving that can't be it. I'd arrange a proper diagnostic if I were you from either a dealer or a good independant.