Just got back from dealer. As predicted they know what happened to my car, but have no idea why. Apparently the fault codes indicated there was a misfire in cylinder 4, which caused it to flag the warning light and go into 'limp mode'. However after a day of checking and 2 test drives there is now no sign of a misfire (and since the warning light went out of its own accord I've driven it about 250 miles with no problems). The test results did mention something about misfires can occur after repeated cold starts, but I don't know if this is relevant in this case. The day before it happened I had driven from Cardiff to Reading in torrential rain then left the car overnight, but can't imagine this would cause any problems.

Anyway, its been given a clean bill of health and the error codes have been reset, so just keeping fingers crossed it doesn't happen again. I'd still be interested to know what would cause a misfire, and if this is a particularly common fault.

 

I flippin' wish mine throw a drivetrain warning light, I've got a persistant misfire but no error codes yet!

 

I flippin' wish mine throw a drivetrain warning light, I've got a persistant misfire but no error codes yet! [/quote

Not sorted yet Marco

 

I've not been able to drop her back yet.

 

Just been tound chatting to Chris on similar (cpcrampton on here) - He had this in his M135i on Friday, drivetrain error, running rough and back firing.

Result was a new battery which sorted all. Diagnosis noted 480 start/stops in one month! He is now disabling as matter of course (auto so cant keep foot on clutch)

 

In some respects I think I would have been happier if they had found a failed component which could be replaced to cure the problem. Although I'm sure everything is now fine, I still have that slight nagging doubt that it might happen again when I'm least expecting it.

 

Just got back from dealer. As predicted they know what happened to my car, but have no idea why. Apparently the fault codes indicated there was a misfire in cylinder 4, which caused it to flag the warning light and go into 'limp mode'. However after a day of checking and 2 test drives there is now no sign of a misfire (and since the warning light went out of its own accord I've driven it about 250 miles with no problems). The test results did mention something about misfires can occur after repeated cold starts, but I don't know if this is relevant in this case. The day before it happened I had driven from Cardiff to Reading in torrential rain then left the car overnight, but can't imagine this would cause any problems.

Anyway, its been given a clean bill of health and the error codes have been reset, so just keeping fingers crossed it doesn't happen again. I'd still be interested to know what would cause a misfire, and if this is a particularly common fault.

First post so Hi all

This sounds very similar to my E90 335i. In the end they replaced all the injectors and coils after a strongly worded letter to the dealership in question after 4 or 6 visits.

I could force mine to do it as follows:

1) Fill up the tank from nearly empty.
2) Give it some stick for 3 miles (Hi revs WOTs etc) until you get to the motorway.
3) Join motorway at speed but settle at an 80mph cruise

Miss-fire after 5 miles. :-(

3 years on, it still fine so I suspect cheap injectors or such like from factory.

 

Useful info Deadeye, thanks for posting.