Z3m Help needed

For the M Powered Z3 derivatives

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Joined: Mon 19 Jun, 2017 14:14
Posts: 3

  M roadster S52

Z3m Help needed

Post by mj007 »


I'm in need of advice and pointers.
My car a z3m (s50) has a major fault in hot weather the car cuts out and will not start again it almost seems like the news is kicking in.
Its happened to me on a few occasions always when it warm outside the last was a two weeks ago on the middle lane of the M25 - no warning lights no stuttering or spluttering just cuts out and will not start for about an hour - after which it starts up again and will drive for another 10-20 mins before it does the same things again.

First time it happened AA came out read the codes and said it was a EWS issue - I have had this replaced.
For the last week the car has been in a specialist bmw garage (well renowned in Stevenage) they have not been able to identify the issue as the car is not throwing up any error codes, They have advised that they do not want to starting changing bits and as they cannot get any errors codes to point to any sensor or even an ECU fault.

I'm not sure where to go from here as my last experience of breaking down on the M25 was not fun.
Would be grateful for any advice or pointers

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Joined: Fri 30 Apr, 2004 16:01
Posts: 3399

  M roadster S50

Re: Z3m Help needed

Post by pingu »

Is the fan running in the ECU box.

The box is top left of the engine bay as you look at the engine.


It may not be the relevant ECU, but it's something to check.

Joined: Mon 10 Nov, 2003 13:17
Posts: 7


Re: Z3m Help needed

Post by miran »

I had problems with a S54 cutting out when hot (in hot weather). No error codes.
Garage changed the fuel pump relay to no effect.
Turned out that it was the fuel pump itself.
Good luck.

Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Z3m Help needed

Post by Del »

As it only happens when the engine is hot, resumes when the engine cools AND causes a total engine stop (as opposed to rough running) I would guess at heat soak into a failing crankshaft position sensor (aka engine speed sensor).

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