Rough idle/start in cold weather?

[Naz24]

Originally Posted by NJ04e53

hi..i just picked up an 04 3.0i on monday and the following day it started to shake like crazy in the morning. It was like 30F here in NJ. The Service engine soon light came on. I took it to denville bmw and they said it was a misfire and took care of it. Light was off and i drove away. following day it started off smooth. Now, no light coming on but started to shake again. I stepped lightly on the gas and suddenly it quiet down. I will call bmw and let them know of this and probably stop by during lunch time since i work next to them. i really hope this is nothing serious..at least they told me before it was not. I guess i'm not the only one after all. I'll also look into all the suggestions that were mentioned in this thread and go from there. Thanks

who is your SA at Denville?

[Tleong]

I too experienced the problem earlier today... I will take it bay diagnostic tomorrow. According to the posts, it seems it could either be an oil separator or thermostat?

[Naz24]

Originally Posted by Tleong

I too experienced the problem earlier today... I will take it bay diagnostic tomorrow. According to the posts, it seems it could either be an oil separator or thermostat?

yeah i'm guessing its the oil separator, it seems like the most common problem

I hope this is CPOd

[Naz24]

okay so my SA today said that it cant be the oil separator for my car., but it was due to gas being in the lines and when the car started in the cold air, there was more gas getting pushed through the lines that the engine could not accept.

idk if this makes any sense....

[anerbe]

^ lol wut?

so he said it's normal. no fix?

[Naz24]

Originally Posted by anerbe

^ lol wut?

so he said it's normal. no fix?

thats what he said. its happened to me bad once, if it starts happening more then i'll start complaining.

[royemaun]

hi all,

my X5 2001 4.4i is rough on idle during start and only in the morning prior to engine breakdown because of blown piston ring and ignition coil, engine is now overhauled, changed the gaskets, valve cover & spark plugs but after a month it seems that the problem did not go away and now it becomes worse. diagnosed it with GT1 and got two cylinder misfires #1 & #2 as per pic attached. my cluster doesn't show the 'check engine light' although the GT1 says it's on. is this a sign to change the ignition coils? mileage is bad on this car as it has 312xxxkm on it and more problems keep coming, like i just solved the issue with the 'trans failsafe prog' and now here it goes again. temp here in saudi is 13 C in the morning but it's getting rougher day after day.

your inputs will be highly appreciated.

thanks

[BeckMule]

FWIW, I had pretty much the exact problem described in the original post: 2005 4.4i about 40K miles, kept in garage, and this past winter (midwest) there were a handful of occassions where immediately on start-up the SUV began to stutter and shake violently until it either died, or I put the car in reverse and started driving. On a few occasions, the Service Engine Soon light came on and I took it to the dealer ... the only error code was something about a fault due to "ambient vehicle environment." At about the same time, I also noticed that the engine was generally idling more roughly than usual and at lower RPMs. Long story short - the dealer replaced the intake manifold ($50 under certified warranty) and the problem vanished. Hope this helps someone else.