I am looking at M3s again, and an intriguing "driver/track" quality M3 has shown up nearby. It has an issue, according to the seller.
The car runs and drives however when left to idle for a bit it will start to run rough. Turn off and back on and it's running fine till it starts to idle again. Engine light will throw misfire at cylinder 4 5 6. I've done every single test possible from compression to pressure leak down test to spark plugs to coils to injectors to oxygen sensors. And I still couldn't figure out what the problem is causing it to run rough as soon as it's left to idle a bit.
I've asked for results from the compression and leak down tests, and the actual codes. Anyone have a miraculous idea? The car looks to be cared for, and has had some of the big M3 needs addressed.
Crap in the fuel rail?
O2 sensor?
Weak coil pack/ driver?
Not a BMW guy, just a few quick things.
Could be the fuel pump not moving fuel from one side of the tank to the other. Mine used to do it, even though it never threw any codes while doing it.
This is my car, see if by running rough he refer to the idle hunting like this:
https://youtu.be/XLVumf6gkfg
It would only do it after idling for a minute or so.
How much and hows the rest of the car? Curious what kind of discount. Should be easy to have an independant shop do a PPI and diag on the issue for a few hundo?
Not much help on the rest but suprised it effects one entire bank. Possibly the O2 on that side once the car goes closed loop? I know they run open loop on warmup before going closed loop after a bit.
Anyone else see this title and their brain instantly translated it to "s--t, help needed," before realizing it said E46?
Yes Curtis, that's how I read M3 always these days. This site has ruined me.
Exhaust leak on the 456 collector?
