Vibration
 

Anyone have any idea where the vibration could be coming from? When I'm in D with brakes on I feel vibration and can hear vibration as well. Once I put transmission in nuetral it subsides. Also turning on AC amplifies it. Could be transmission or engine mounts? 2002 4.6is 77k miles.

Sounds pretty much like the motor mounts, though sometimes some people say it gets better with AC on because the idle up with it on.

A test someone posted (twinturboGTR IIRC) was to put it in drive, step on the brakes, engage park brake, (chocks would be a good idea too I think) then goose the throttle a bit.

IIRChe said broken mounts will cause significant engine movement doing this

I am going to take it to a shop to see if they can figure out the problem. Engine mounts seem like a pita and probably will cost more then I'm willing to spend especially after I just dropped $2400 on replacing all fluids, upper and rear gaskets, spark plugs, filters, front shocks, and all fluids including transmission oil.

Yeah, they are kind of a pain on the V8's sorry to say. IIRC one side is pretty tight.

The 3.0 is loads easier in this regard.

You'd be surprised on the difference a set of engine mounts would make. I replaced mine last year at 98K due to engine vibration etc. My X is a 2003 X5 4.6is. The mounts flatten over it 13 years of operation. When I changed them it was a night and day difference.

Did you do it yourself?

Yes

Are there any diy treads on this topic? I searched but came up with nothing.

I don't think it is conclusive the cause is the motor mounts. It could be transmission related or transfer case related. I would do more trouble shooting such as checking to see if the transmission is at the proper level and making sure the fluid was per specs since it was recently changed. And get the help of someone, secure the vehicle and see if you can find the source of the sound.

There will be excess engine movement when the vehicle is in drive and held by brakes and the engine RPMs increased.

Scale of 1-10 how much of a bitch is it to DIY? I have just under your miles but same age on my 3.0 and I think the engine takes a beating with my MT