Hi, last night our 02 F-250 SD 5.4/auto stared ok but after about 2 miles the idle went to about 2000-2500 rpm and would not go down. I shut it down and restarted and jumped up to 3000 rpm. Shut it down and restarted a second time went to 2500. Ended up driving home at 2500 RPM Tranny all shifitng funny and hard shifts. Un-hooked the Batt for 12 hours went out and re started and did the Same thing.... Well today it cooled down to the 50's and now getting a Knock/clattering after about 10 seconds of running.Just did a oil change last Mon, if that helps.
Any help would be great.
Going to have it towed to my mech tonight.

Thanks
Dave