2003 GMC GMC TRUCK Engine And Engine Coolingengine Problems

I NOTICED SINCE I BOUGHT MY 2003 GMC ENVOY THAT THE MOTOR WOULD RACE IN THE AM UPON STARTING. I TOOK THIS AS NORMAL UNTIL THE RACING NEVER STOPPED ONE DAY. I TOOK IT TO MY LOCAL GM DEALER AND THEY INFORMED ME THE FAN CLUTCH HAD FAILED AND REPAIRED IT FOR OVER 700$. UPON RESEARCH LATER ON THIS PART I NOTICED PEOPLE SAYING THESE ARE FAILING AT A REGULAR BASIS. NOW, I'M NOT A MECHANIC, BUT I THINK HAD I NOT THE KNOWLEDGE I DO OF AUTOMOBILES, I WOULD HAVE CONTINUED TO DRIVE AND POSSIBLY COULD HAVE HAD A MAJOR ENGINE FAILURE OF SOME SORTS. THIS COULD HAVE RESULTED IN A SERIOUS INCIDENT ON THE ROADS. MY VEHICLE HAD ONLY 40,000 MILES ON IT. NOT MANY, CONSIDERING THE IMPORTANT OF OPERATION OF THIS PART. *NM

MISSING AND THEY SEEM NOT ABLE TO FIX IT SOME TIMES IT SHIFTS HARD OTHER TIMES IT BACKFIRES IT HAS BEEN IN THE SHOP TWICE ALL THEY CAN SAY IS THE COMPUTER SHOWS NOTHING AND THAT HOW THE ENGINE RUNS AND THAT IS UNACPECTABLE TO ME FOR A NEW TRUCK. *LA