Definitely check the codes. Another thing to research are intermediate levers. I get rough idle intermittently on very cold mornings.

You say happens mostly in the mornings. Has it been very cold in your area?

two? pretty sure we have one OSV (~$35) at back of passenger side head and one PCV (~$100) at the back of the intake mani. u must be super quick to do both in 15minutes...

OK so the error codes were
P0303
P0307
P0306 misfires in those cylinders.

He said they already checked..the oil seperators, for a vacuum leak and now as i said they are cleaning the injection system - he said there is a low injector pulse (sprays - low)
When i mentioned the intermediate levers - he said they want to make sure they check everything before they get to that, because it is a pretty expensive repair.

Thank you all for your advice!!!

Just don't let them throw parts at the X. You said you already spent $1400 so I hope you can trust them.

I'm pretty sure my rough idle problem on very cold mornings are the intermediate levers. I'm going to live with it until I can't anymore because, as you said, they are a expensive repairs.

Good luck and let us know how it all plays out.

Yes... there's two. One on top of each valve cover. This is on the 05+ 4.4l

You're probably mistaking the pressure regulating valves (#13 below) for the oil separator.


http://www.realoem.com/bmw/diagrams/i/e/218.png

Yep. That's them... I always thought those were the oil separators. woops.

well... when I changed those thingamabobs I stopped getting crappy idle at start up in the mornings. :)

Thanks for the clarification. :)

Thanks for the tip. I might just go ahead and replace them as they're very inexpensive compared to the intermediate levers.

I rarely get the rough idle on cold starts as it doesn't get too cold around here usually. However, I'll probably do it the same time when I need to do the valve cover gaskets.

Wait .. those are on TOP of the covers. Even easier. LOL! Now I regret not taking up SlickGT1s offer on those valves.

Well in live in SW Florida, so it doesn't exactly ever get 'cold' here. :) More of a 'haven't started the engine in a few hours' type of symptom.