Rough Idle On Cold Days?

[Weebie]

I have a 2006 X5 E53 4.8is and I get a rough idle when it is really cold outside. It does not seem to be a cold start issue as the problem is still apparent when I've driven the car for well over an hour.

I know the 4.8is has a bigger exhaust and it seems like the cold weather is causing the exhaust to rumble, which causes my car to shake and vibrate very rough. The vibrations feel like my X5 has message chairs and the steering wheel shakes. The rough idle is more apparent when the car is stopped at a stoplight with the engine engaged in drive. The vibrations lessen when I put it to neutral and park.

I've taken the car to a couple dealers already and when they hooked it up to the computer there were no error codes, engine misfires, and etc. It checks up as everything is running fine so they have no idea what is wrong.

So here is my question for all the other 4.8is owners on here. Is what I am experiencing normal for the 4.8is in the cold winters due to the larger exhaust? Or is there something really wrong with my X5? I don't experience these rough idles when the weather is warm.

Any suggestions and input would be greatly appreciated.

TIA

[killcrap]

most likely failed eccentric shafts. they are known to cause rough running.

[X5 Meister]

Have them check the intermediate levers on the valve timing gear. That was a known issue for 2004 & 2005 X5's with the N62 engine (which includes the 4.8is), produced from 6/04 up to 2/05 production. Problem was technically fixed after that and for the 2006 model year, but you never know.

From the SIB: "Incorrect tolerances and geometry of Valvetronic intermediate levers are causing uneven cylinder filling during the transitional cold start period (60 seconds after the engine has been started) when the Valvetronic system is switching from the initial 6 mm to a minimum 0.3/0.8 mm valve lift."

[mrkbbd]

mine has been doing the exact same thing here in DC, and if I don't move within 3 minutes of starting, the engine basically stalls and the fuel management revs the engine and then moves it to a high idle

[X5 Meister]

mrkbbd what car do you have (& production date)?

[mrkbbd]

'06 4.8is with an August '05 production date

[X5 Meister]

see my edited post above (#3)

[mrkbbd]

thanks X5 Meister, I already have a service appt for the 3rd week in March, so I'll bring that bulletin with me

[X5 Meister]

Do you already have that bulletin?

[mrkbbd]

I just meant your text, I'm sure they can look it up when I get there, unless you have the actual one