100 of the
1,614 complaints about the 2000 Chevrolet Silverado are about the
engine — 6% of everything
reported for this model year.
Half of the failures with a mileage on record happened before
63,875 miles.
A
100
Complaints
1
Crashes
0
Fires
1
Injuries
Exactly what failed
Gasoline
4242.0%
Engine
2525.0%
Engine AND Engine Cooling
1111.0%
Exhaust System
66.0%
Emission Control
33.0%
Cooling System
33.0%
Engine
33.0%
Radiator Assembly
22.0%
Manifold/Header/Muffler/Tail Pipe
22.0%
GAS Recirculation Valve (Egr Valve)
11.0%
Engine & Cooling across every Chevrolet Silverado year
TL* THE CONTACT OWNS A 2000 CHEVROLET SILVERADO. WHILE THE VEHICLE WAS STOPPED WITH THE AIR CONDITIONER ENGAGED, THE VEHICLE BEGAN TO OVERHEAT. IN ADDITION, THE CONTACT STATED THAT THE TEMPERATURE GAUGE DISPLAYED A HIGH READING. THE FAILURE RECURRED ON NUMEROUS OCCASIONS. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHO DIAGNOSED THAT THE WATER PUMP AND ANTI-FREEZE NEEDED TO BE REPLACED. THE VEHICLE WAS REPAIRED; HOWEVER, THE FAILURE RECURRED. THE MANUFACTURER WAS NOT NOTIFIED OF THE FAILURE. THE FAILURE MILEAGE WAS UNKNOWN.
NHTSA complaint #10823123 — an unverified report by a vehicle owner.
at 140,000 milesNEW Stanton, PA
ENGINE
TL* THE CONTACT OWNS A 2000 CHEVROLET SILVERADO. THE CONTACT STATED THAT WHILE PARKED, HE NOTICED A LOUD TICKING SOUND. THE CONTACT INSPECTED THE VEHICLE AND NOTICED THAT THE INTAKE MANIFOLD BOLTS WERE FRACTURED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE VEHICLE WAS NOT REPAIRED. THE APPROXIMATE FAILURE MILEAGE WAS 140,000.
NHTSA complaint #10536267 — an unverified report by a vehicle owner.
at 94,800 milesWillard, UT
ENGINE
DURING A UTAH STATE SAFETY INSPECTION LAST YEAR IT WAS FOUND THAT 3 OF THE 12 EXHAUST MANIFOLD BOLTS WERE BROKEN ON MY 6.0L ENGINE. THE BOLT HEADS WERE COMPLETELY BROKEN OFF/MISSING. THE BROKEN BOLTS ALLOW THE EXHAUST MANIFOLDS TO LEAK CAUSING PROBLEMS WITH EMISSIONS. IF LEFT UNDETECTED THIS PROBLEM CAN CAUSE THE CATALYTIC CONVERTER TO FAIL. JUST TO HAVE THE BOLTS REPAIRED IS A VERY EXPENSIVE >$500 REPAIR THAT COULD HAVE BEEN AVERTED BY HAVING THESE FAULTY BOLTS CHANGED OUT EARLY ON. ONCE THE BOLTS ARE BROKEN THEY HAVE TO BE EXTRACTED WHICH IS VERY DIFFICULT DUE TO THE THERMAL DEFORMATION AND CORROSION. TWO OF THE BOLTS WERE IN THE REAR MOST HOLES WHICH HAVE VERY LIMITED ACCESS. I HAVE NOT RECEIVED ANY NOTICES FROM THE MANUFACTURER IN REGARDS TO THIS PROBLEM. I HAVE OWNED THIS TRUCK SINCE IT WAS NEW. I WOULD LIKE TO REQUEST A RECALL FROM THE MANUFACTURER DUE TO THE FACT THAT IT CAUSES EMISSIONS PROBLEMS AND INCREASES POLLUTION. IF YOU CONSIDER HOW MANY OF THESE TRUCKS, TAHOES, AND SUBURBANS HAVE BEEN ON THE ROAD SINCE 1999, THE INCREASE IN POLLUTION IS CONSIDERABLE.
NHTSA complaint #10474341 — an unverified report by a vehicle owner.
Lansing, MI
ENGINE AND ENGINE COOLING
THE EXHAUST MANIFOLD BOLTS ARE BROKEN OFF (ONE ON EACH SIDE AT THE REAR OF THE MOTOR RESULTING IN AN EXHAUST LEAK (TICKING NOISE) AND ALSO CHECK ENGINE LIGHT "ON" BAD EMISSION CODES.
NHTSA complaint #10426695 — an unverified report by a vehicle owner.
at 88,950 milesHudson, WI
ENGINE AND ENGINE COOLING
ENGINE EXHAUST MANIFOLD BOLT NEAREST THE FIREWALL BROKEN ALLOWING RAW UNTREATED ENGINE EXHAUST TO BE EXPELLED INTO ATMOSPHERE. EXHAUST SMELL IN PASSENGER COMPARTMENT AT SLOW SPEEDS.
NHTSA complaint #10426382 — an unverified report by a vehicle owner.
at 88,950 milesHudson, WI
ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE
ENGINE EXHAUST MANIFOLD BOLT NEAREST THE FIREWALL BROKEN ALLOWING RAW UNTREATED ENGINE EXHAUST TO BE EXPELLED INTO ATMOSPHERE. EXHAUST SMELL IN PASSENGER COMPARTMENT AT SLOW SPEEDS.
NHTSA complaint #10426382 — an unverified report by a vehicle owner.
at 79,650 milesBroadalbin, NY
ENGINE AND ENGINE COOLING:EXHAUST SYSTEM
CHEVY SILVERADO TRUCK HAD EXHAUST LEAK(6.0LITER). UPON INSPECTION, EXHAUST MANIFOLD BOLT HEADS WERE NOTED TO BE BROKEN OFF. AFTER TALKING WITH OTHER SILVERADO OWNERS, THEY ALSO HAD THE SAME PROBLEM WITH THE EXHAUST MANIFOLD BOLTS.
NHTSA complaint #10251113 — an unverified report by a vehicle owner.
at 38,000 milesManistee, MI
ENGINE AND ENGINE COOLING:ENGINE
DT*: UPDATED 10/25/2006 - EVERYTIME THE VEHICLE WAS STARTED AND THE ENGINE WAS COLD, IT MADE A KNOCKING NOISE, WHICH CONTINUED UNTIL THE ENGINE WARMED UP. THERE WERE NO WARNING SIGNS PRIOR TO THE INCIDENT. THE VEHICLE WAS TAKEN TOT HE SERVICE DEALER WHO SAID THE NOISE WAS CARBON BUILD-UP ON THE PISTON. THE DEALER TRIED RUNNING CLEANER INTO THE ENGINE TWICE BUT THE NOISE WAS STILL THERE. THE DEALER SAID IT WAS PISTON SLAP MAKING THE NOISE AND THAT IT WAS OK TO DRIVE.
NHTSA complaint #10170558 — an unverified report by a vehicle owner.
at 35,226 milesFletcher, NC
ENGINE AND ENGINE COOLING:ENGINE
THE ENGINE IN MY 2000 CHEVY HAS A KNOCK AND TAPPING NOISE THIS HAS BEEN A ONGOING PROBLEM I HAVE TALKED TO TWO CHEVY DEALERS AND THEY SAY IT IS NORMAL BUT IT KEEPS GETTING WORSE THE MILEAGE NOW IS 76585 .
NHTSA complaint #10157917 — an unverified report by a vehicle owner.
at 70,000 milesRIO, WI
ENGINE AND ENGINE COOLING:ENGINE
2000 K3500 SILVERADO HAS HAD THREE FAILED FUEL INJECTOR PUMPS, FUEL TRANSFER PUMP, AUTOMATIC TRANSMISSION AT 70,000 MILES AND BOOST REGULATOR FAILED. *TS WHEN THE CONSUMER REMOVED THE ENGINE,TO EVALUATE THE DAMAGE, TO SEE IF IT COULD BE REBUILT, HE DISCOVERED THE SECOND MAIN BEARING CAP FROM THE FRONT OF THE ENGINE WAS MISSING A BOLT.
NHTSA complaint #10157318 — an unverified report by a vehicle owner.
Worcester, MA
ENGINE AND ENGINE COOLING:COOLING SYSTEM
2000 SILVERADO HEATER HOSE BROKE OFF AT THE FIREWALL CONNECTOR. *TS THE PART WAS MADE OF PLASTIC (NYLON. THE REPLACEMENT PART WAS MADE OF THE SAME MATERIAL.
NHTSA complaint #10151920 — an unverified report by a vehicle owner.
at 57,750 milesCharleston, WV
ENGINE AND ENGINE COOLING:ENGINE
GENERAL MOTORS 2000 SILVERADO TRUCK-BRAKE PROBLEMS-OWNER FINANCED REPAIRS-REAR BRAKES AND TIMING BELT ($1,800 DEALER)-MOST RECENT FRONT BRAKES-RUSTED ROTORS-RETAILER REPLACED ($200). SUSPECT DEFECTIVE MATERIALS MANUFACTURED BY GM RESULTED IN EQUIPMENT FAILURES. DEALER SHOULD BE RESPONSIBLE TO REFUND REPAIR COSTS TO CONSUMER.
NHTSA complaint #10144940 — an unverified report by a vehicle owner.
at 15,000 milesWeymouth, MA
ENGINE AND ENGINE COOLING:ENGINE:GASOLINE
I AM WRITING TO SEEK SOME ASSISTANCE WITH AN INFERIOR PRODUCT PRODUCED BY GM. I HAVE A CHEVY 2000 SILVERADO Z71 PICK UP THAT HAS PISTON SLAP STARTING AT AROUND 15K MILES AND PROGRESSIVELY WORSENED WHICH THE DEALER STATES IS NORMAL WEAR. THIS EXPENSIVE VEHICLE ALSO HAS A REAR END BANG INTO DRIVE AND THEN REVERSE AGAIN THE DEALER STATES IS NORMAL. RECENTLY I FIXED A SNAPPED CABLE FOR THE DRIVERS WINDOW WHICH THE SAME KIND OF CABLE WAS RECALLED FOR THE TAIL GATE CABLES. I HAVE REPLACED RECALL ITEMS FOR THE TAIL GATE CABLES, DRIVE SHAFT YOLK AND THE ABS SENSORS TO WHICH IT IS STILL NOT FUNCTIONING PROPERLY. ALL OF WHICH WHEN PRESENTED TO THE DEALER AND THE RESPONSE WAS IT IS NORMAL, UNTIL THE RECALL OCCURRED. IT SEEMS THE POLICY OF A COMPANY WHICH CREATES AN INFERIOR PRODUCT IS TO STATE, "IT IS NORMAL" TO THE CONSUMER UNTIL THE GOVERNMENT STEPS WHEN ENOUGH PEOPLE COMPLAIN AND MAKES THE DEALER OWN UP TO THE PROBLEMS WITH THE PRODUCTS AND FINALLY TREATS THE CONSUMER WITH MORE COMPASSION, AND TO SOME DEGREE "DECENCY". WITH THE MANY PROBLEMS WITH THIS VEHICLE THE GOVERNMENT NEEDS TO STEP IN AND HELP THE CONSUMER WITH THE DEALERSHIP RESISTANCE TO FIX THE PROBLEMS CAUSED BY MORE CONCERN FOR PROFIT THAN QUALITY.
NHTSA complaint #10144921 — an unverified report by a vehicle owner.
Harlan, IA
ENGINE AND ENGINE COOLING:ENGINE
2000 CHEVROLET SILVERADO DEVELOPED PROBLEMS WITH THE BRAKES AND THE ENGINE.*MR THE ENGINE KNOCKS WHEN STARTED DUE TO PISTON PLAY.
NHTSA complaint #10135621 — an unverified report by a vehicle owner.
Perkasie, PA
ENGINE AND ENGINE COOLING
EXCESSIVE ENGINE KNOCK ON COLD START HOT OR COLD WEATHER EVERY DAY BEEN TO 2 DIFFERENT DEALERS AND WAS TOLD WAS NORMAL AND IT SEEMS TO GET WORSE AS I PUT MILES ON TRUCK ONLY HAVE 48K ON IT AND CHANGE OIL EVERY 3K.
NHTSA complaint #10134826 — an unverified report by a vehicle owner.
at 75,100 milesHenniker, NH
ENGINE AND ENGINE COOLING:COOLING SYSTEM
THE BRAKES ON MY TRUCK DO NOT STOP THE TRUCK IN A REASONABLE DISTANT. WHEN I PULLED OFF THE WHEELS YOU COULD SEE WHERE THE PADS ON THE FRONT WHEELS WERE ALMOST GONE, BUT THE REAR SHOES WERE HARDLY WORN. I DID CHANGE THE FRONT PADS. I ALSO HAVE THE STICKING GAS PEDAL PROBLEM WHICH I HAVE HAD THE DEALER WORK ON WITH NO RESULTS.
NHTSA complaint #10111883 — an unverified report by a vehicle owner.
at 112,000 milesNapoleon, OH
ENGINE AND ENGINE COOLING:COOLING SYSTEM
I HAVE TWO GENERAL MOTORS VEHICLES. A 2000 SILVERADO TRUCK AND A 97 OLDS SILHOUETTE. BOTH OF THESE HAVE V6 ENGINES AND NOW I AM BEING TOLD THAT BOTH OF THEM HAVE INTAKE MANIFOLD LEAKS. THE ANTIFREEZE IS LEAKING OUTSIDE OF THE INTAKE, AND IN THE CASE OF MY TRUCK, PROBABLY INTO THE ENGINE. I AM BEING TOLD THREE DIFFERENT MECHANICS, THAT THIS IS A VERY COMMON PROBLEM WITH THE V6. AND AFTER VOICING MY COMPLAINT, FOUND THAT MY BROTHER-IN LAW, HAS HAD THE SAME PROBLEM. I CALLED THE GENERAL MOTORS NUMBER IN THE MANUAL AND TOLD THEM THAT I WAS UPSET WITH THE PROBLEMS AND THEY SAID THAT BECAUSE ONE IS A 97 WITH 62000 MILES, IT IS TWO OLD AND THAT MY TRUCK HAS TO MANY MILES (112000). YET EVERYONE TELLS ME THAT IT IS THE PLASTIC INTAKE MANIFOLDS THAT GM USES THAT IS THE PROBLEM.
NHTSA complaint #10106581 — an unverified report by a vehicle owner.
at 38,800 milesBrewster, OH
ENGINE AND ENGINE COOLING
EXCESSIVE TICKING AND ENGINE NOICE DURING COLD START UPS. I WAS TOLD, BY CHEVROLET SERVICE THE TICKING WAS NORMAL BUT SHOULD NOT LAST MORE THAN 1 MINUTE. HOWEVER AFTER DIGANOSING THE PROBLEM, IT WAS DISCOVERED THAT MY 2000 CHEVROLET SILVERADO 1500 HAS A BAD LIFTER. THIS AFTER ONLY 38000 MILES. I FILED A CLAIM WITH CHEVROLET THEY REFUSED TO PICK UP ANY OF THE $1300. IN REPAIR COSTS. MY TRUCK HAS A VORTEX V6, WHICH GM HAS BEEN MANUFACTURING IN EXCESS OF 20 YEARS. THE BUGS SHOULD BE WORKED OUT BY NOW, BUT AFTER READING THE NUMEROUS COMPLIANTS, WITH REGARD TO THE SAME PROBLEM, THE BUGS CLEARLY HAVE NOT BEEN WORKED OUT.
NHTSA complaint #10096462 — an unverified report by a vehicle owner.
at 82,312 milesCassopolis, MI
ENGINE AND ENGINE COOLING
WE PURCHASED A 2000 SILVERADO 2500. THERE IS A KNOCKING NOISE IN THE ENGINE. WE TOOK IT BACK TO THE DEALERSHIP TO LOOK AT AND NOTHING COULD BE DONE ABOUT IT. GM IS WELL AWARE OF THE KNOCKING NOISE IN THE VORTEX 6.0 ENGINE. THEY TOLD US THAT THIS WAS A COMMON PROBLEM. IT DOES NOT MATTER IF IT IS A COLD START OR IF IT RUNS ALL DAY.
NHTSA complaint #10086833 — an unverified report by a vehicle owner.
Tomah, WI
ENGINE AND ENGINE COOLING:ENGINE
ENGINE WAS MAKING A KNOCKING SOUND WHILE IDLING. *PH THE CONSUMER WAS TOLD BY THE DEALER THAT GM WAS AWARE OF THE PROBLEM, HOWEVER THERE WAS NO FIX. THE DEALER ALSO STATED THE PROBLEM WAS DUE TO A PISTON SLAP.
NHTSA complaint #10066868 — an unverified report by a vehicle owner.
at 32,000 milesColeman, OK
ENGINE AND ENGINE COOLING
ENGINE KNOCKS ON STARTUP...WAS TOLD BY THE DEALER IT IS NORMAL...BULL@#$#...WE ARE HARD WORKING PEOPLE WHO MUST DEPEND ON OUR VEHICLE TO GET US TO WORK...I DO NOT TRUST THIS TRUCK VERY FAR FROM HOME. FYI TO ALL OTHER OWNERS...THERE IS A CLASS ACTION PENDING ON THIS PROBLEM. WE DIDN'T PLAN ON PAYING THIS MUCH FOR A VEHICLE JUST FOR IT TO SOUND LIKE THIS. OTHER DEALERS ARE AWARE OF THIS PROBLEM..SO TRADING IT OFF WITHOUT LOOSING YOUR SHIRT IS IMPOSSIBLE.
NHTSA complaint #10064330 — an unverified report by a vehicle owner.
at 32,000 milesColeman, OK
ENGINE AND ENGINE COOLING:ENGINE
ENGINE KNOCKS ON STARTUP...WAS TOLD BY THE DEALER IT IS NORMAL...BULL@#$#...WE ARE HARD WORKING PEOPLE WHO MUST DEPEND ON OUR VEHICLE TO GET US TO WORK...I DO NOT TRUST THIS TRUCK VERY FAR FROM HOME. FYI TO ALL OTHER OWNERS...THERE IS A CLASS ACTION PENDING ON THIS PROBLEM. WE DIDN'T PLAN ON PAYING THIS MUCH FOR A VEHICLE JUST FOR IT TO SOUND LIKE THIS. OTHER DEALERS ARE AWARE OF THIS PROBLEM..SO TRADING IT OFF WITHOUT LOOSING YOUR SHIRT IS IMPOSSIBLE.
NHTSA complaint #10064330 — an unverified report by a vehicle owner.
Gowanda, NY
ENGINE AND ENGINE COOLING
ABS OCCASIONALLY FAILED DUE TO WATER, DIRT, AND RUST GETTING IN THE SENSORS. *LA CONSUMER ALSO COMPLAINED OF THE ENGINE KNOCKING. HE WAS THEN INFORMED THAT THE CAUSE WAS CARBON AND THE AMOUNT OF CLEARANCE BETWEEN THE PISTONS AND THE CYLINDER WALL. THEY REDESIGNED THE PISTONS FOR THAT REASON.
NHTSA complaint #10061117 — an unverified report by a vehicle owner.
Delevan, NY
ENGINE AND ENGINE COOLING
VEHICLE IS EXPERIENCING PROBLEMS WITH ENGINE MAKING A KNOCKING NOISE AND THE BRAKE SYSTEM MALFUNCTIONING. *LA
NHTSA complaint #10061032 — an unverified report by a vehicle owner.
Manassas, VA
ENGINE AND ENGINE COOLING:ENGINE
I OWN A 2000 5.3 VORTEX V8 IN MY CHEVROLET AND THE ENGINE MAKES HORRIBLE NOISE WHEN ITS COLD, REFERRED TO AS SLAPPING OF THE PISTON SLEEVE. WHAT CAN BE DONE ABOUT THIS IF ANYTHING. SEEMS LIKE AN ON GOING PROBLEM FOR MANY GM OWNERS AND SOMETHING THAT IS ONLY RESOLVED ONCE A BIG STINK IS MADE OF IT BEFORE ANY POSSIBLE ACTION IS DONE. I REALLY LOVE MY TRUCK BUT, THIS IN CONJUNTION WITH THE NOISE I GET IN COLD WEATHER GOING OVER SPEED BUMPS OR UNLEVELED SURFACES IN THE SHOCK OR THE FRAME. I HAD ALL KINDS OF PARTS REPLACED AND IT STILL COMES BACK IN COLD WEATHER, ALONG WITH THE KNOCKING NOISE ON COLD STARTS. ANY ADVISE OUT THERE FOR A RESOLUTION? THANKS NHALL.
NHTSA complaint #10058798 — an unverified report by a vehicle owner.
at 70,000 milesCincinnati, OH
ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE
I OWN A CHEVROLET 2500 SILVERADO TRUCK, FOUR WHEEL DRIVE WITH THE 6.0 LITER ENGINE. THERE ARE THREE BOLTS BROKEN OFF IN THE INTAKE MANIFOLD OF THE TRUCK DUE TO WHAT I BELIEVE WAS OVER TORQUING AT THE FACTORY.
NHTSA complaint #10056993 — an unverified report by a vehicle owner.
Mcdonald, OH
ENGINE AND ENGINE COOLING:ENGINE
MY 5.3 LITER SILVERADO HAS A DIESEL LIKE NOISE IN THE MOTOR UNTIL IT REACHES NORMAL RUNNING TEMPERATURE, THEN IT RUNS GREAT. ITS VERY LOUD THE FIRST 30 SECS. FROM A COLD START. MY LOCAL GM GARAGE SAID THAT IS NORMAL FOR A 4.8 AND A 5.3 MOTOR. THEY CALLED IT PISTON SLAPPING, TO ME IT IS VERY ABNORMAL. AND WILL IT GET WORSE, I ASKED. THEY HAD NO ANSWER. THEY DID COMMENT THAT GM HAS NOT RESOLVED THIS BULLETIN YET. I LOVE MY TRUCK, I HOPE I GET 200K MILES OUT OF IT. NOW I ONLY HAVE 50K . WHAT'S A PERSON TO DO IF THE MAKER OF HIS FAVORITE AUTO CAN'T COME THROUGH WITH A RESOLUTION. IT ALSO AFFECTS RESALE VALUE IF I DECIDE TO SELL.
NHTSA complaint #10056637 — an unverified report by a vehicle owner.
at 14,000 milesLincolnville, ME
ENGINE AND ENGINE COOLING
UPON STARTING VEHICLE COMPUTER SHOWED CODE B2960 WHICH MEANT ENGINE WON'T START AGAIN, AND WILL TAKE LONGER TO START. VEHICLE WAS TAKEN TO THE DEALER WHERE VEHICLE WAS BOUGHT, AND DEALER COULDN'T REPRODUCE THE PROBLEM. VEHICLE WAS TAKEN TO ANOTHER DEALER AND STILL HAD THE PROBLEM.
NHTSA complaint #10057429 — an unverified report by a vehicle owner.
at 27,324 milesSikeston, MO
ENGINE AND ENGINE COOLING:ENGINE
WHILE DRIVING VEHICLE SLAMS HARD INTO GEAR. ENGINE CHECK LIGHT EITHER COMES ON BEFORE OR AFTER THIS OCCURS. DEALERSHIP SERVICED VEHICLE 4 TIMES BUT THE PROBLEM STILL EXISTS.
NHTSA complaint #10057157 — an unverified report by a vehicle owner.
at 85,000 milesSouth Milwaukee, WI
ENGINE AND ENGINE COOLING:ENGINE:GASOLINE
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
NHTSA complaint #10055090 — an unverified report by a vehicle owner.