Rough start and knocking - then fine.
Hello fellow bimmer enthusiasts.
I am having an issue (or more) with my 2001 503i.
Throughout Summer she was rough starting kind of sluggish, I have to assume something fuel related, as if shes not getting enough fuel.
If I try to drive off, its like theres no gas/acceleration. If I drove for another 2-3 mins, it was fine for as long as I drove. Then there are times where it would rough/sluggish start as it did, have the same issue with gas/acceleration, and I would drive to a gas station/coffee shop (short distance). Stop the engine, come back to it and as I put it in reverse, it would go about 5-10 feet, then the engine would die completely. I would restart it back up, and it acted like nothing was ever wrong.
Fast forward to November in MN. 23 degrees outside.
Now that rough start up has turned into a VERY rough start up accompanied by a loud knocking coming from the top (or so it seems on initial inspection) of the engine.
The knock is occasional, about every 7-15 seconds. The car goes to a very low idle and has died twice. Otherwise it keeps going but keeps knocking. If I keep it revved around 1500-2000 RPM it seems ok, but the idle does drop as it seems its not getting enough gas. I keep it revved occasionally and do this for about 5-10 mins. Which after that is absolutely fine, no idle issues, no knocking.
Until the next time I start it again....