I just got my 06 SE (used, 17k miles) a couple of months ago and changed from a luxury car that was smooth as silk, so I just may be noticing something that is normal for a more trucklike vehicle. Seems like my engine vibrates a lot at idle. Engine has lots of power and gets reasonable mileage in town (16+ mpg in-town driving), so I don't think it is missing or anything like that. I just feel a lot of vibration thru the steering wheel and my rump when sitting at idle and wonder whether I have a broken engine mount or something like that. Opinions????

Do you have a manual transmission or automatic? If auto, does the vibration occur in Park, or in Drive, or both? Does the vibration lessen when in motion? or is it worse?

Good questions. Should have put the info in the original post. It is automatic trans. Idles at 750rpm in park/neutral with some vibration, and drops to about 700rpm in drive (at a stop) with distinctly more vibration. Accelerates and shifts smoothly, with almost no vibration while in motion.

I have an 07 x, One of the cars I own is a semi luxury (acura) plus other vehicles.
What I can tell you, is that my x, has a bit more vibration when in park, then my other vehicles, but I attribute it to the type of motor and the amount of soundproofing/motor separation between us and the motor.
I definately hear and feel the motor more in the x. In my acura, and a sequoi I have, the vibration is much less felt and quiter.
However I have an infinit m35, and the motor is definatly loud and prominent in the cockpit, and you can feel it through the steering wheel more. Real nice ugly vehicle, but the motor sounds a bit raw.Doesnt drive that way.
But since you are under warranty, why dont you have it checked out. Always to be safe. Could be a loose or damaged motor mount, or something worse.
Have it checked out for piece of mine, under the computer.

Good luck and stay safe

The engine is noticeable in our cars more so than a luxury or semi-luxury car. When I was purchasing, during the test drives of Xterras I noticed some had a slight more vibration than others. So being a PITA, I had the dealer pull keys for all black SE's in stock and started every single one.

I have a 05, automatic that has this problem. Its more prevelent when the weather is cool and or raining! Only when in gear and at a stop light/sign. And at times when the AC is on..Its fine when moveing.. Nissian replaced the motor mounts and that helped a little bit. But now its seems to be getting worse over the yrs and millage! One thing is the vehicle is not vibrating at all, its just a vibration noise!

I just bought a used 2008 Off Road edition, 22K miles, automatic, spotless inside and out, I did a lot of crawling underneith it and I can't find any signs of abuse. I have also noticed that it vibrates a lot when in park and when in drive but stopped, like when sitting at a stop light. I have just chalked this up to the fact that it's a truck and not a lux vehicle. Aside from trying to damage the vehicle, e.g. pissed at the dealer or lease company, is there anything someone can do to an 08 in 22k miles that would cause it to vibrate more than it should?