idle vibration while transmission in drive
 

e53 3.0 here

she idles smoothly in park and neutral. while at a stop and in drive there is lots of vibration throughout the cabin. let go of the brake and the idles smooths out. while accelerating there is zero vibration - smooth like in park or neutral.

in park/neutral the engine idles around 700 rpm; in drive around 500 rpm; noticeable drop in rpm when going from park or neutral to drive.

any ideas?

I'm having similar symptoms, kind of stumped myself

out of curiosity - have you tried anything?

(I haven't as I've been reading loads of threads throughout the Internet; a lot of folks take the rip and replace method with seemingly little success.)

I am in the process of getting a OBD2 USB cable and INPA installed to see if I can see anything out of the ordinary that my Peake tool cannot identify. I have no service engine light on.

This bugs me too.. It comes and goes, possibly related to temperature. I tried to research and it has been attributed to many things from vacuum leak, failed CCV, to torque converter. For what it's worth I replaced all leaking vacuum hoses, and it still vibrates.

The drop in rpm is normal when selecting D from neutral or park. Have you Considerd motor mounts and trams mount? People overlook them, and assume they last indefinitely....the rubber on them ages just like everyother piece underneath the X. Furthermore since they directly attach the engine and driveline to the chassis, could easily transmit vibrations like you describe.

Mine does this as well.

X5SND's suggestion makes sense. Can you visually inspect to tell if they need replaced?

I'm not sure about visually inspecting them...as you would probably have to have some significant movement to see anything on the mounts.

SlickGT1 mentioned a diagnosis procedure....something like loading the driveline (foot on brake, while giving throttle) with the hood, while a second person watched from the side for movement. ---I can't recall the exact procedure, but search through his posts and you'll come across it! (It was for a 4.8, so I'm not sure if it can be applied to an I6....I don't see why not though as the physics are the same)

I to have started to notice an increase in vibration at rest (in gear), along with a slight pounding when I cross a set of ruts (in an intersection) at speed. The fact that I've replaced every link, arm, ballpoint and bushing front to back (not related to this issue) leads me to the only ones that are still original. I had planned to do the motor, trans and diff mounts this spring anyway.

Yeah i get the annoying vibration as well i sometimes just have to giuve it some gas when its really loud. I think it may be Motor mounts as well

You are correct in this. I only suggest parking the car perpendicular to a curb. The brakes will always overpower the throttle, but just in case you mess up, you want to have a curb in front of you. So hold the brake, hard, put in drive, and jab the throttle, don't be a wuss. If the engine moves more than an inch you have a problem. Do same in reverse. This will work for 3.0 as well.

When my mounts died, doing the above test made it seem like the engine was going to flip out of the engine bay. Driver side was completely detached, and engine would lift a good 3" - 6" from rest position. Our mounts are also oil filled. So when they go, expect vibration to show up fairly quick.

Thanks Slick!