My xc70 (let hand drive) rolls when in park, anybody have any similar problems or idea waht is causing this? It only started to do this very recently.

Also when I take my foot off the gas the RPM drops to idle and I get a noise from in front of my feet in the lower engine compartment. This is much worse when on the highway. Both problems seem to be concurrent.

 

The two may not be related... I am to assume this is an all wheel drive. My drive shaft going between the transmission (transfer case) to the rear differential had loosened up and was causing a high speed rattle. By design, these bolts holding on the front cv-joint to the propeller (like the old u-joints) can all fall out without letting the drive line fall out. Loose or missing, these bolts need some "Lock-tite" on them when reinstalled... I believe blue, my bolts didn't have any and vibrated loose. This could cause something like what you are describing... of coarse the park locking pin may be faulty for the rolling... my inclination is that the shift cable is needing adjustment or replaced. Good Luck! Russ

 

Problem solved. It was a broken right front drives shaft causing the symptoms.

 

I lent out my car this past weekend, and a grinding noise was reported
when driving at highway speed.

He pulled over, shifted to park, the took off again and it never returned.
(sound to me like the car attempted to go into park, while driving)

Now,
Rolls in park on inclines.
Would not engage into reverse this AM, is good now.
It slips in lower gears,
AWD seems to be malfunctioning (took on to gravel road and the front
barely pulled at all, as the rear spun out.)

 

Check your front driveshafts. It sounds like one has broken. I had the same thing happen, it was my front right drive shaft had broken.