Occasional rough idle and minor surge.
I have watched and read this site for quite some time and now I need help and finally joined. I have a 01 7.3L F250 with just over 200k. The problem is when I go to warm it up, from time to time the RPMs will fall and idle rough for 30 seconds or so then come back to normal idle. Then, from time to time when I am driving and keeping the throttle steady and at a constant speed I can feel the motor pick up rpm and stay there for 15 seconds or so then I can feel the rpms go back down to normal. It doesn't do this all the time but occasionally. Then today the truck died on me twice today with no CEL light and no smoke.
I also have one more question. I have this thumping coming from the passenger side at idle. There is about a haf second or so between each thump.
I appreciate all of your input