Soaked interior followed by engine misfire - E46

[Smartass]

Hi all,

My 03 E46 coupe took a bath on Friday night. All the windows opened and the car unlocked in the pissing rain and it stayed that way all night, so the interior got pretty moist. I think it was a spontaneous failure rather than me being ham-fisted with the key fob (I'm pretty paranoid about making sure the car isn't unlocked at night) but you never know, it might have been in contact with something in my pocket. So far there's been no repeat of the problem which does point to he possibility that it was human error.

Now the car, which was running perfectly before Friday, has a really serious misfire. It doesn't sound like all six cylinders are firing. I can't get it to my local specialist until tomorrow but I'm curious. Can anyone think of any link between the seats getting a soaking and the car developing a misfire? Obviously I'm worried about the ECU, but I can't believe BMW would make a car so frail. If that is the case, I might as well chop it in and buy a TVR.

Any help appreciated folks, cheers as always
Smartass

[4rephill]

Can't say there would be any link between a misfire and the windows unlocking, but there have been plenty of cases of E46 owners with their remote and keys in their pockets sitting down inside their house and not realisng that they've inadvertently operated the remote, opening the windows and unlocking the car.

[Matthew_Eames]

The ECU is in a sealed plastic box in the engine bay....there is no real way for that to get wet at all.

Coilpacks are common failure points on these engines, I would try removing them one by one and see which is at fault...then get a replacement if required.

It's very easy to do and might save you a diagnostic fee... here is a guide (for an M3 but all are similar)

Edited by Matthew_Eames on Sunday 9th January 16:30