I did some more reading and will replace my fuel filter next. I overlooked that and it is a lower cost approach. I will post it when I complete the job. Thanks again fellas.

 

Fuel filter didn't fix my idle. Helped with MPG though.

 

I'm wondering if leaking valve seals (which the N62 is prone to have) can be causing idle roughness.

 

My cars not eating oil or puffing smoke.

 

Still following thread. Having idle vibration still as well. Hopefully we can try a few things and come up with a solution for all. Mine happened after installing new spark plugs. Attempted a few sets since without any change. Most recent changed fuel filter sender assembly. No change except a little more performance.

 

Found this Looks like i Finally discovered BMW V8 secret!!! - Bimmerfest - BMW Forums. Its 7 series related but same n62 motor. Might not be cause of bouncing idle but is interesting.

 

Just coming in on the tail end and haven't read all posts, so excuse me if this SB has already been discussed.

My 2004 545i was doing a lot of idle rpm hunting, dipping below 500rpm and almost dying before recovering. I suggested this SB to my Indie. He instead used some injector cleaner and that seemed to correct the problem.

However, I have kept it in the back of my mind for the future.

 

Thank you, I've been looking for that SB.

 

Not sure if it helps but I chased a similar issue with my 545i. I replaced my maf sensor all vacuum hoses and lines, finally cleaned my vanos solenoids and it cleared for up for a day or so. It ended up I had slightly overfilled my oil at my last oil change and it was messing up the vanos. It was barely over the full mark on the dipstick.

 

You said slightly overfilled, so your crank was probably not splashing into the sump.

Overfilling the crank case can turn catastrophic quickly as the splashing crank drives air into the oil in the sump, changing your oil into a frothy mess that has almost zero lubricating ability. Journal bearing and ring failure doesn't take long.