2 days ago my x started making a clunking sounds while accelerating especially when going up any size incline..does it on level ground just not quite as bad. The sound is coming from under my feet it sounds and feels like, also when it starts doing this the rpms seem to surge and its like the transmission is confused as to what gear it should be in. I can be on the highway and be doing 55mph and when its running right my rpms are at 1500 but when my x starts this it jumps to over 2k. Its done this before and then it stopped but its driving me crazy. The engine seems to be hesitant while in gear but seems fine when out of gear. Does anyone have a clue as to what might be going on? Thanks in advance.