Just drove from Palm Coast to Tampa, FL, smooth, fast flawless until I get to the stop position. More research suggests Harmonic balancer or torque converter. But trans shows
no signs of dysfunction in any other gear, shift or speed. And when the brake is released and the engine idles it moves away slowly and the vibe disappears. It shifts smoothly at any speed whether using the sport shift manual system or simple automatic shift.
Harmonic B, most research claims that has the car warms up the rubber seal swells and softens thus reducing and eliminating vibration until complete failure. Most say the vibration becomes less as the car runs at normal temp. Not mine, the vibration is always there no matter what the temp, and it can start out very slight and then build to a very intense vibration the longer I sit in "D" brake engaged. AS soon as I shift into "N" the vibe subsides but doesn't disappear completely. I can't keep throwing money at it. ONE thought; do these X5, 3.0 engine mounts have to be Hydraulic? I have replaced engine and tranny mounts. The tranny mount removed was fine. Soft, not torn up or hardened and cracked. This is a real problem many have experienced. The engine
isn't vibrating erratically at idle. Plugs have been replaced. Intake boots replaced, MAF cleaned. Air filter replaced. Disa rebuilt and new.
Who knows ?? What the BMTrouble U knows?

Try some octane booster. When I was in Mississippi over a year go the stations there sold a 94 octane gas and Boy Howdy did my X like it. Peppy and ran much smoother. Perhaps your engine just can't stomach 91 with ethanol. Or maybe try 100% gas and see if that makes any improvement.

That might be a possiblitly, but I have run 93 on the last four tanks. Drives like a rocket.
It's only at idle it's having vibration issues.

Nothing?!

Vanos?
You should be able to look at your harmonic balancer and see if it has cracks.

mechanic checked tranny fluid, it was full and red. Checked what he could of the balancer and it seemed ok. Thing is this particular vibration may in fact be torque converter related, because it only vibrates radically in gears, never in neutral and you can barely hear the engine idle. Tomorrow, it goes to European Auto Service in Atlanta. I'll keep you posted.

I'll be curious what EAS finds out. You'd think something causing that much vibration would be obvious to pin point. Crazy

Subscribe!

VIBRATION...Just going to live with it. Took it into EAS in Atlanta and got nothing for my 300. bucks. They said it vibrates because the idle is low and there is nothing I can do about it. Really? It idles at the first line above 0. Moves up slightly in "N".
The guy took apart the serpentine belt because he thought it looked unevenly worn, it wasn't , just the top because of the idler pulley. Then he did a smoke test, no leaks, no vacuum issues, then a scan / reader, no codes, no nothing. He did have fun driving the crap out of it on the 285. Even said he would buy it because it was in such great condition. BUT, alas, I still have a vibration, now out 600 bucks, new motor mounts and tranny/case mount, which happen to be in fine condition before the trade out. This is sad. SO, what's the deal with idle issues on X5 -3.0's? MAF AND ICV,which he cleaned up all work fine. Strangely it does vibrate less with the A/C on in "D" at stop. Good thing, it's about to get very hot here in Atlanta I am told, and the A/C works great. Don't think I 'll be going down the BM trouble U road again in the future. BTW, anyone suggest a fair price for replacement rear taillights - the right one is rotted out, already fixed it once. It's toast and I need a new one. Can I upgrade to LED or will I get the light on the dash? Suggestions for company? Ebay? Thanks to everyone for trying to diagnose this issue. Done throwing money at it for awhile. Enjoy the ride. Miss my E30 rags.

E30 ftw!