2010 GMC SIERRA Engine Problems

ENGINE LIFTER ISSUE/LOW OIL PRESSURE PROBLEM RELATES TO HAVING THE LIFTERS REPLACED. THE 5.3 VORTEC ENGINE HAS AFM (ACTIVE FUEL MANAGEMENT). DEALER WANTS $5800 TO FIX THE LIFTER ISSUE, WHILE ESTIMATES TO REPLACE THE ENGINE WITH NECESSARY PARTS RUNS BETWEEN $6900 AND $7200. IS THIS A MANUFACTURER PROBLEM? TRUCK HAS 52,000 MILES AND HAS BEEN SERVICED AT REGULAR INTERVALS. TRUCK WAS PARKED WHEN THE ISSUE BECAME EVIDENT DURING THE STARTUP. TRUCK IS NOW AT THE DEALER (TOWED) AWAITING REPAIR.

ENGINE STOPPED RUNNING, DASH GAUGES BLANK. I MANAGED TO PULL OVER WITHOUT POWER BRAKES OR STEERING! AFTER A FEW MINUTES I WAS ABLE TO RESTART WITH "REDUCED ENGINE POWER, TRACTION CONTROL OFF, AND STABILITRAC" PROBLEMS DISPLAYED ON DASH. I WAS A MILE FROM HOME IN -10F TEMPS! I PULLED IT INTO MY SHOP. DTC CODE P2135 WHICH HAS TO DO WITH THROTTLE POSITION SENSOR. THE DEALER HAS A 2 WEEK DELAY IN GETTING INTO THEIR GARAGE! I FOUND OUT THAT THE THROTTLE BODY/SENSOR IS NOT COVERED UNDER WARRANTY. SO WITH THE COST OF A TOW (CAN'T TRUST THE TRUCK TO MAKE TO DEALER) PLUS THE PART COST, I WILL REPAIR IT MYSELF. THE REASON FOR THIS LETTER, I DISCOVERED THAT THIS HAS HAPPENED TO OTHER GMC TRUCK OWNERS. THEIR VEHICLE QUIT IN THE SAME MANNER. I THINK THAT "REDUCED POWER" IS NOT THE SAME AS NO POWER!!! I WONDER WHAT...