My 07 JK drops in RPM's and sort of shakes but not bad at a idle. It doesnt happen very often. My JK has 18k miles and has had a recent oil change. I just got it while i was deployed to Afghanistan so ive only drove it 800 miles since ive had it back in May. Have no idea if previous owner has done tune-up or anything. Jeep hasnt been abused there are no scraps or dings, rust or even a slight hint of mud. Dont think it was due to anbuse but maybe it needs new spark plugs?. Also there is no noises associated when the RPM's drop just the slight shudder of the engine. I fix it by reving the RPM a couple of times and it goes away. Any ideas.