I started hearing a clunking noise when I come to a stop. it sounds like the engine is moving or something. Today it started to do it and the rpm's also went up and down. Also had a little sputter going up hill this morning.
No check engine light or any visible problems.
Does anyone have any ideas?
Thanks alot.

 

You have a bad anti-clunking sensor. Just kidding... Do you mean you think the engine is moving or coming loose from the motor mounts? What is the RPM at idle and how much does it go up and down? I'm not sure if the 4.6's had plug issues (blowing them out), but I'd check all of them. Sounds like it could be a mis-fire if no CEL. Were the plugs changed on it yet?