XSeries-forum

Looking for some advice please!! Apologies for the long post.
I have a bmw x6 f16 3.0d. Since owning it it has had a vibration throught the whole car even when rolling. In drive or reverse when it starts rolling even without pressing the accelator. When the accelarator is pressed then it goes away slightly but comes back intermittently. More noticeable at slow/rolling speeds or when slowing down.
The car came with 22 inch alloys and 285 35 22. I swapped these to 285 30 22 so the circumference is <1% of the oem sizes.
Also swapped transfer case, changed oil and calibrated which made no difference at all.
The front driveshafts were very difficult to reinstall back into the hubs - could this be an issue with this symptom even at rolling speeds?
Also the rear of the car seems to be very high like the air suspension is maxed out to its limit.
Anyone have any ideas what this could be?
Any help is much appreciated.

Was any of this apparent before you did any work on the car?

You say ‘even when rolling’ which implies that it’s doing it when stationary. Is it, or isn’t it? What’s the mileage? Does the vibration rate change with all speed or just with engine speed?

What happens at higher speeds?

If it’s doing it when stationary then the removes everything other than engine and its ancillaries (power steering pump, air conditioning system pulleys etc. Have you had the error codes read? Did anything show up?

Any odd driving noises? Grinding noises or jerkiness, especially at walking speed in full lock.

It could be the driveshafts but you changed the transfer box not a diff, so why were the driveshafts removed, or do you mean the front propshaft? What did you (or a mechanic) use to recalibrate the system?

Other things to check are for warped brake discs, sticking calliper (that you can find by putting a hand on each wheel centre after a drive, and if one is warmer than any other is the ‘problem’ wheel). Could be a buckled/bent wheel. Wheel balance.

You need to be careful with tyre choices as that can lead to problems. If all 4 are the same and no more than 2mm difference in tread depth between any of them, that should be fine.