525i Not running right [Archive] - Bimmerfest - BMW Forums

: 525i Not running right

12-12-2009, 09:04 PM
I was driving the car up a steep hill so put my foot down a bit, the car got to about 4500rpm made a very quick Rev limiting noise and now only runs on a few cylinders plus i got petrol spitting out the exhaust and it smells quite potent with Gas :( Not good!

Any ideas or anyone had this problem before? Dont like taking my car to the Shop to get diagnosed it cost so much!

12-13-2009, 01:01 AM
the only way raw fuel can get to the exhaust is through the exhaust valves. IE, it gets injected into the cyl, compressed, fired, then exhausted. If, on the compression stroke, the exhaust valve does not seal to the head, the raw fuel will be pushed out into the exhaust. At the same time, the fuel will not be compressed, and therfore, not fired, making that cyl in-op.....

I'm not sure what you should be looking for though. I have heard that the cams will wear down on the M50 due to improper oiling. This should be gradual, not all at once.

12-13-2009, 06:21 PM
Funny you should mention that.. When i brought the car it had bad Tappet noise, and its been about 2 months of loud as **** tappets, do you think its gotten to the point of the Cams being just enough off to make the timing a little crooked?