1993 Saturn SL2 RPM go crasy

HALLO
WHEN MY CAR IT'S ON THE ROAD RUNNING AFTER A GOOD TIME (20 MINUTES) IT RUN TO 70 TO 80 KHS AND SODENLY THR RPM INDICATOR JUMP FROM
2000 TO 3500 AND WE CAN EAR THE MOTOR SOUND GO HIGH REVOLUTION AND THE CHECK ENGIN LIGHT GO ON.
IF I SHOT DOWN THE ENGIN AND START BACK IT GO OK BUT IT START BACK IN FEW MINUTE

IT DO LIKE WHEN THE CAR IT ON PARK AND YOU PRESS ON GAZ PEDDLE BUT WHEN IT DO THAT THE CAR IT MOVING IF I PRESS ON GAZ IT MOUVED
NORMALY BUT THE RPM INDICATOR GO WILE

THANK YOU IF YOU FIND A SOLUTION.