3-Series (E46, E90)Chat relating to the BMW 3-Series from 1999 to Current. Models include: BMW 316i, BMW 318i, BMW 318Ci, BMW 320i, BMW 323i, BMW 325i, BMW 330i, BMW 328 Ci, BMW 328i, BMW 325i/xi, BMW 330Ci, BMW 320d, BMW 330d, BMW 335d.
The engine was running rough with the check engine light on. I did some of the basics (oil change, spark plugs). I was still rough. Seems the air intake boots were in bad shape so I replaced thouse. At this point, the car is running better going down the road, and idles fine at first, but after an extended idle, it begins to run rough again and throughs on the engine light. The code reader indicates random misfires on all 6 cylinders. Any ideas on where to look next. Is it a vacumn problem and how can i tell?
Thanks for the posts. Here is an update. Vacumn system appears to be sealed up. The coils and wires are giving correct voltage to the spark pulgs. However, the idle problem persists. I get codes from my Peake R5 / FCS -3 code reader as follows:
My local mechanic claims that the fuel system needs to be reset by the dealship, that it has adapted to runnin gwith the vacumn leaks and needs reset now that they are fixed. Has anyone ever heard of that? Any other suggestions before I take to the dealship 2 hours away?
Sounds like you might have a hose leaking air for the compression. I just had the same problem with my car. There was a small hose on the top of the engine under the cover right by the air flow sensor. I had the same codes when i ran a scan. I thought initially it was the ignition coil but i could hear air leaking from that point. Do a sound test first and see if you are leaking any air. If that is not the problem check the coil and follow this video.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.