BMW 3 Series cuts out and will not start / starts half hour later

Have you had the immobilizer checked?

Hi

Check also the cam position sensor, if there is oil in the connector its definetely junk,ut may also be electronically defective, typically cutting out and intermittent non starts are symtoms

Donut

This problem is symptomatic of a crank sensor fault rather than cam as the ecu looks for the crank sensor on starting and not the cam sensor. It will only look for the cam sensor on starting if it cannot se a good crank signal. This needs to be checked by a garage eqipped with a good scope.

I have just posted a problem with my 5 series diesel. Does not start after a few hours sitting, cranks over, sounds like fuel being delivered but does not start, was also wondering if immobiliser could be at fault. Read my problem to see if it sounds similar. I replaced fuel pump relay today but has not cured.