[E93Blackhawk]

Been having a issue with my 335i lately.

Took it to the garage, it threw a code but had no description under it so i have to get a full diag check which is happening later this week.

Anyway, I have absolutely no clue what this could be. But my mpg is 13.2 and i'm driving VERY carefully lol.

Anyway on a cold start there is this sort of 'knocking' sound, and my rev limiter seems to be jumping up and down which is sort of when the knock happens. Misfire?

I know many will just say get your car plugged in, but im so curious why my mpg is SO shocking and what part/parts could be contributing to the following:

1 Knocking sound on cold start
2 Rev limiter is hovering at 500rpm and needle is jumping a little bit up and down
3 Car seems as powerful as it was when the problem wasnt there.
4 Mpg is sitting at 13.2
5 Dont think its a coil issue as the engine sounds fine throughout rev band

If there was a misfire or one of the cylinders wasnt going then the car would be down on power i presume, and that hasnt happened.

The knocking sound is ONLY when the car is at idle on a cold start.

If anyone could have a think i would be grateful

Thanks

[skatenc123]

no idea what it could be. but if you know the code post it and im sure somebody could tell you what the code is.

[E93Blackhawk]

Originally Posted by skatenc123

no idea what it could be. but if you know the code post it and im sure somebody could tell you what the code is.

Good idea, ill ring the garage in the morning.

Stupidly didnt take down the code.