Chevrolet Repair: vibration in motor, crank pulley, chevy s10

Question
1997 chevy s10 2.2l 157k vibration of motor while revving, new motor mounts, cranksleeve and pulley, timing chain and tensioner.
Crank pulley sleeve was coming loose from crank, replacing it fixed it for awhile. Now it has returned and torqing crank no longer changes the severity. Thrust bearing in motor?

Answer
HI MARK,TRY REMOVING THE DRIVE BELT AND START IT LIKE THAT AND SEE IF IT STILL VIBRATES.IF NOT PROBLEM IS NOT THE ENGINE..THIS WOULD BE RARE [THE ENGINE]..WHEN THIS HAPPENS CAN YOU TAKE A LONG BAR AND TRY TO LIFT THE ENGINE ON ONE SIDE OR ANOTHER TO SEE IF THE VIBRATION STOPS OR CHANGES. POSSIBLE ALIGNMENT PROBLEM WITH FRAME AND ENGINE ???? LOOK FOR ANYTHING THAT COULD BE HITTING.INCLUDING THE TRANSMISSION MOUNT,EXHUAST.. WHAT IS STRANGE IS THAT WHEN YOU REPLACED THE CRANK PULLEY THE VIBRATION WENT AWAY FOR AWHILE ??? ARE YOU SURE THE NEW PULLEY IS OK,  WAS THE VIBRATION COMPLETLY GONE OR JUST SO-SO ?? I HAVE SEEN MANY PROBLEMS WITH SOME PART OF THE ENGINE HITTING ON THE FRAME CAUSING THIS.. THE FACT THAT IT ONLY HAPPENS OFF IDLE DOES NOT SOUND LIKE ENGINE PROBLEMS TO ME.GET BACK TO ME ON THIS IF YOU NEED TO. .ALSO COULD YOU PLEASE RATE MY ANSWER, THIS WILL HELP ME. THANKS TOM..