NHTSA Complaint #756904 — 2000 CHEVROLET SILVERADO

WITHIN A MONTH AFTER OUR PURCHASE, I TOOK OUR TRUCK TO TONY CHEVROLET'S SERVICE DEPT. FOR AN ENGINE KNOCK. I WAS TOLD THIS NOISE IS NORMAL TO "ALL" 2000 CHEVROLET AND GMC TRUCKS WITH THE 5.3 LITER ENGINE. I ASKED HOW AN ENGINE KNOCK CAN BE NORMAL TO A BRAND NEW ENGINE AND WAS TOLD THAT THE NOISE WAS CALLED "PISTON SLAP" WHICH GENERAL MOTORS IS AWARE OF THIS "DEFECT" AND WAS WORKING ON A FIX. I THEN EXPLAINED TO THE SERVICE WRITER, SINCE I'VE WORKED AS A MECHANIC, THAT I'VE NEVER HEARD A NEW OR REBUILT ENGINE KNOCK UNLESS THERE WAS A MISTAKE MADE OR A FAULTY PART INSTALLED. I'VE HEARD HIGH MILEAGE ENGINES WITH A KNOCK PROBLEM, AND I'VE HEARD HIGH MILEAGE ENGINES WITH "PISTON SLAP". AFTER RESEARCH I FOUND OUT GM WAS GOING TO REPLACE THE FAULTY PISTONS WITH GM'S NEW DESIGN PISTONS AND THAT WOULD TAKE CARE OF THE "PISTION SLAP" ISSUE. AFTER TALKING WITH ANOTHER DEALERSHIP ABOUT THIS ISSUE, I WAS TOLD THAT GM HAS REPLACED A FEW ENGINES WITH THE NEW DESIGNED PISTIONS WHICH NOW STILL HAVE THE "PISTON SLAP". I WAS SHOWN BULLETIN # 01-06-01-028 WHICH STATED MODELS:1999-2002 CHEVROLET/GMC PICKUP & UTILITY MODELS,2002 CADILLAC ESCALADE (2WD) WITH 4.8L,5.3L OR 6.0L ENGINES MAY EXHIBIT AN ENGINE KNOCK NOISE THAT BEGINS IN THE FIRST 12,000-15,000 MILES OF USE. THE KNOCK NOISE IS MOST OFTEN NOTICED DURING START-UP AND TYPICALLY DISAPPEARS WITHIN THE FIRST 5-30 SECONDS (MAY LAST LONGER IN EXTREME COLD TEMPERATURES) SINCE WE LIVE IN ALASKA THIS IS VERY TRUE. THE NOISE IS USUALLY MORE NOTICEABLE ON THE INTIAL START-UP WHEN THE TEMPTURE IS BELOW 50 DEGREES AND MAY BE MORE PRONOUNCED ON THE FIRST START FOLLOWING A LONG TRIP. THE NOISE "MAY" BE CAUSED BY AN INTERACTION BETWEEN CARBON THAT HAS FORMED ON THE PISTON, THE PISTON MOTION AND THE CYLINDER WALL. AT THIS TIME, ATTEMPTS TO REPAIR THIS CONDITION BY REPLACING THE ENGINE ASSEMBLY OR PISTONS IS NOT RECOMMENDED. OUR TRUCK'S PERFORMANCE HAS GONE DOWN DUE TO THE KNOCK SENSOR DETECTING THIS PARTICULAR PROBLEM.*AK