N62 4.4L rough idle
 

I have a 2004 X5 N62 4.4L with 135K miles on it. It always start nicely. The problem is when outside temperature is below freezing and as soon as I shift the transmission, 7 times out of ten the engine is running rough and if the outside temp is lower, it's getting worse. The idle is so rough, it's hard for me to get out the garage. At minus 30F, the engine went in the Engine fail safe mode when driving. I had very often the P0300 code and a few P0444. I did change my spark plugs and my fuel filter without any improvement.

Here's my observations:
1- the rough running last for about 2 to 3 minutes and disappears by itself. Sometimes (very few), it doesn't disappears, I shut off the engine, wait about 1 minute crank again and the engine runs smoothly like new. I did that also for the fail safe mode and it worked.
2- less problem when the fuel tank is full
3- no problem when the engine is warm

If you have any suggestion, please let me know, Thanks

This topic has been discussed numerous times with different solutions. Do a search on the rough idle issue.

One thing that comes to mind is when was the last time you services the CCV's? If you do short drives, there may be cheese under those diaphragms.

You can start here:
http://www.xoutpost.com/bmw-sav-foru...d-weather.html

And welcome to the forum fellow Montrealer....

I like to call it mayo instead since I dont like it and neither does a bimmer hahaha

Thanks all for your lightning replies... Sorry to started a new thread on a old problem:sorry: I already ordered this morning the 2 PCV valves and I'll be back with the update on the fix... Thanks again:thumbup:

I've also been told two bottles of ISO HEET in the gas tank can help. I'm having the same problem, replaced both CCV's and it's still there. I've searched every store in a 20 mile radius and all the ISO HEET is sold out at every single one.

Brandon , I thought your problem was solved? Mine is still holding up but this morning I felt a very small vibration ( 2 secs maybe) .

Mine got better, but not solved on cold morning starts.

Sounds like you might have valvetronic intermediate levers and shafts issues. You can test or have this tested by running the engine with the valvetronic in failsafe and then cold start

Did my PCV change last weekend, lot of mayonnaise in the valve and in the piping. Clean everything and the engine runs smoother but again in cold this morning , as soon as I engaged in reverse, the engine bucked and the engine light in the dash flashed. I have to look again somewhere else...


Sarek: Thanks for your reply but how can I do this test by myself?