2020 GMC Sierra 1500
Problems, recalls and owner-reported issues
Engine is the leading concern among 468 owner complaints filed for this model year. This is the 7th highest complaint count among 26 Sierra 1500 model years with reports.
Of the 2020 reports, 12 involved a crash and 5 involved a fire. 13 people were injured.
What owners report most often
Recalls and investigations
Power train, automatic transmission, control module, softwareFeb 12, 2026
General Motors, LLC is recalling certain 2020 Chevrolet Silverado 2500, 3500, GMC Sierra 2500, 3500, and 2020-2022 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles that may have been repaired incorrectly under recall 24V797. The transmission control valve may fail and cause the rear wheels to lock up.
Rear wheel lock up increases the risk of a crash.
Dealers will inspect the vehicles and update the transmission control software, free of charge. Owner notification letters were mailed March 6, 2026. Owners may contact GMC customer service at 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N252516560. Vehicle Identification Numbers (VINs) involved in this recall became searchable on NHTSA.gov on February 12, 2026.
Campaign 26V083000 on NHTSA.gov
Power train, automatic transmission, control module, softwareOct 24, 2024
General Motors, LLC (GM) is recalling certain 2020-2022 Chevrolet Silverado 1500, 2500, 3500, GMC Sierra 1500, 2500, 3500, 2021 Cadillac Escalade, Escalade ESV, Chevrolet Tahoe, Suburban, GMC Yukon, and Yukon XL vehicles equipped with diesel engines. The transmission control valve may fail and cause the rear wheels to lock-up.
Rear wheel lock-up can increase the risk of a crash.
Dealers will install new transmission control module software, free of charge. GM will provide a special coverage program to cover the repair of transmissions that are identified by the remedy software as containing a defective control valve. Owner notification letters were mailed December 12, 2024. Owners may contact GM customer service at 1-888-988-7267, Cadillac customer service at 1-800-458-8006, GMC customer service at GMC 1-800-462-8782 or Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N242454440.
Campaign 24V797000 on NHTSA.gov
Tires, temporary/emergency spare tireDec 16, 2021
General Motors (GM) is recalling certain 2019-2021 GMC Sierra 1500 and Silverado 1500 vehicles equipped with certain accessory road tires and a 17" spare tire. The 17" spare tire provided with the vehicle is not compatible for use with the accessory wheels, which can cause the anti-lock brake system (ABS) to not function properly under certain conditions.
An ABS system that does not function properly can increase the risk of a crash.
Dealers will provide a new 17" spare tire and wheel assembly that is compatible with the accessory wheels, free of charge. Dealers will also apply a new spare tire information label, and provide owners with an owner's manual insert clarifying which spare tire to use with the accessory road tires and with the 17" original tires. Owner notification letters were mailed February 7, 2022. Owners may contact GM customer service at 1-800-462-8782 or GMC customer service at 1-800-462-8782. GM's number for this recall is N212346510.
Campaign 21V985000 on NHTSA.gov
TiresFeb 25, 2021
General Motors LLC (GM) is recalling certain 2020 Buick Enclave, Cadillac XT4, XT5, Escalade, Escalade ESV, Chevrolet Suburban, Tahoe, Traverse, GMC Yukon, Yukon XL, 2018-2021 Chevrolet Express, GMC Savana, 2019-2020 Chevrolet Blazer, Silverado 1500, GMC Acadia, Sierra 1500, and certain Continental tires sold to the aftermarket for various model year 2018-2021 vehicles. The affected tires were cured for too long during production.
Over cured tires may develop a break in the sidewall resulting in sudden air loss or a belt edge separation which could lead to a tread/belt loss. Either condition can cause a loss of vehicle control, increasing the risk of a crash.
GM will notify owners, and dealers will inspect the tires, replacing them as necessary, free of charge. The recall began March 22, 2021. Owners may contact GMC customer service at 1-888-988-7267, Buick customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N212329050.
Campaign 21V115000 on NHTSA.gov
Seat beltsDec 17, 2020
General Motors, LLC (GM) is recalling certain 2019-2021 Chevrolet Silverado 1500 and GMC Sierra 1500, 2021 Chevrolet Suburban and Tahoe and GMC Yukon XL and 2020-2021 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 vehicles. The seat belt brackets may not be secured to the seat frame in the front-row center seating position.
If a seat-belt bracket is not secured, the seat belt may not properly restrain an occupant in the front-row center seat position, increasing the risk of injury in a crash.
GM will notify owners, and dealers will inspect left-side and right-side front-row center seat-belt bracket attachments and reassemble it correctly as necessary, free of charge. The recall began January 26, 2021. Owners may contact GMC customer service at 1-800-462-8782, Chevrolet customer service at 1-800-222-1020. GM's number for this recall is N202314670.
Campaign 20V792000 on NHTSA.gov
TiresNov 5, 2020
General Motors LLC (GM) is recalling certain 2020 Buick Enclave, Cadillac XT5, GMC Acadia and Chevrolet Traverse vehicles and 2020-2021 Chevrolet Silverado 1500, GMC Sierra 1500 vehicles. The vehicles may have been manufactured with Continental tires that were overcured.
Overcured tires may experience a carcass break in the sidewall resulting in a sudden air loss or could develop a belt edge separation which could lead to partial or full tread/belt loss. Either condition increases the risk of a crash.
GM will notify owners, and dealers will inspect vehicles and replace tires that have DOT number and production mold number combinations identified by Continental, free of charge. The recall began December 17, 2020. Owners may contact GMC customer service at 1-888-988-7267, Buick customer service at 1-866-608-8080, Chevrolet customer service at 1-800-222-1020 or Cadillac customer service at 1-800-458-8006. GM's number for this recall is N202319030.
Campaign 20V684000 on NHTSA.gov
Power train, driveline, driveshaftOct 22, 2020
General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500 and 2020 Chevrolet Silverado 2500 trucks. One of the driveshaft joints may not have been properly welded, causing the driveshaft to separate while the vehicle is moving.
If the driveshaft separates, there may be a loss of propulsion, increasing the risk of crash.
GM will notify owners, and dealers will replace the driveshaft, free of charge. The recall is expected to begin December 2020. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N202314870.
Campaign 20V650000 on NHTSA.gov
Air bags, side/window, curtain, inflatorJul 30, 2020
General Motors, LLC. (GM) is recalling certain 2020 Buick Enclave, Cadillac XT5 and XT6, Chevrolet Blazer, Silverado 1500, 2500 and 3500 and Traverse and GMC Acadia and Sierra 1500, 2500 and 3500 vehicles. The diffuser component of the Roof-Rail Air Bag (RRAB) inflator may not have been properly crimped to the inflator and could separate from the inflator during air bag deployment.
If the diffuser separates from the inflator during deployment, RRAB performance may be degraded, increasing the risk of injury in a crash.
GM will notify owners, and dealers will replace the suspect RRAB modules, free of charge. The recall began September 3, 2020. Owners may contact Chevrolet customer service at 1-800-630-2438, Cadillac customer service at 1-800-333-4223, or Buick customer service at 1-800-521-7300. GM's number for this recall is N202305380.
Campaign 20V446000 on NHTSA.gov
Service brakes, hydraulic, foundation components, disc, caliperFeb 27, 2020
General Motors LLC (GM) is recalling certain 2020 Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles. The bolts used to attach the front and/or rear brake calipers may have not been heat treated and may break under load.
Broken caliper bolts can reduce brake performance or interfere with wheel rotation and increase the risk of a crash.
GM will notify owners, and dealers will replace the brake caliper bolts, free of charge. The recall began March 23, 2020. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-866-522-9559. GM's number for this recall is N202294420.
Campaign 20V116000 on NHTSA.gov
Electrical system, 12v/24v/48v battery, cablesDec 12, 2019
General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500 trucks. The battery positive (B+) cable rings may have been manufactured with excessive glue, potentially causing an intermittent electrical connection between the B+ cable and alternator.
An intermittent electrical connection between the B+ battery cable and the alternator could cause the vehicle to stall, increasing the risk of a crash. The intermittent connection could also lead to electrical arcing, which could generate sufficient heat to damage surrounding material, increasing the risk of a fire.
GM will notify owners, and dealers will inspect for the presence of glue or other contamination at the B+ cable attachment to the alternator and clean the connection and reattach the B+ cable connection, as necessary. If arcing has damaged the cable, nut, or alternator, the dealer will replace the damaged components. All services will be performed free of charge. GM issued owners an interim notification on February 4, 2020. GM issued second notice and the recall began March 9, 2019. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N192273510.
Campaign 19V888000 on NHTSA.gov
Fuel system, gasoline, delivery, fuel pumpNov 21, 2019
General Motors LLC (GM) is recalling certain 2020 Cadillac Escalade, Escalade ESV, Chevrolet Camaro, Silverado 1500, Suburban, Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles. The fuel pump may be missing a pressure regulator, allowing for over-pressurization of the fuel system.
Over-pressurization can crack the fuel pump and cause leaks, increasing the risk of a fire in the presence of an ignition source.
GM will notify owners, and dealers will replace the fuel pump, free of charge. The recall began December 18, 2019. Owners may contact Cadillac customer service at 1-800-333-4223, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-888-988-7267. GM's number for this recall is N192283991.
Campaign 19V837000 on NHTSA.gov
Seat belts, pretensionerNov 14, 2019
General Motors LLC (GM) is recalling certain 2019-2020 Chevrolet Silverado 1500 and GMC Sierra 1500, and 2020 Silverado 2500, Silverado 3500, Sierra 2500, and Sierra 3500 vehicles equipped with carpet floor covering. When the front seat belt pretensioners deploy, hot gas may vent through an opening in the pretensioner bracket, possibly igniting the carpet.
A vehicle fire could result if materials ignite inside the vehicle.
GM will notify owners, and dealers will close off the opening in the pretensioner bracket, free of charge. The recall began December 13, 2019. Owners may contact Chevrolet customer service at 1-800-222-1020 or GMC customer service at 1-888-988-7267. GM's number for this recall is N192270600.
Campaign 19V814000 on NHTSA.gov
Representative owner complaints
468 reports, newest first.
Electrical system, Engine, Sep 28, 2026
6 months after owning it the lifters went bad got them Fixed then they immediately went bad again also bent rods then a day after getting that fixed again the oil pump went bad it was issue after issue
Power train, Vehicle speed control, Sep 28, 2026
The vehicle in questions was purchased with less than 5 miles in year 2020. This vehicle was dropped off at MAC HAIK CHEVOLET MADISON MS on September 25, 2026. I was advised on September 28, 2026, that the vehicle was test driven with the scan tool connected, Graph Torque converter slip, found over 100 RPM slip when torque converter engaged and causing shutter at highway speeds, also felt 1-2 and 2-1 harsh downshift, check fluid condition was black and smelled burnt, replace transmission assembly, flush cooler, program transmission control module and perform clutch fast learn. Estimated cost of $8k
Engine, Sep 24, 2026
While slowly accelerating from a stop, with 4 family members in the truck, the engine began to run rough for about 1-2 seconds then multiple notifications flashed across the dashboard (Check Engine, Steering Assist is Reduced-Drive with Care, Service ESC, and Service Parking Brake). The road we were on was steep and twisty and did not have room to pull over which put us in an unsafe position with compromised steering and no shoulder. We made it 2 miles home but there was smoke coming from the exhaust and the engine ran very rough. Truck was towed to my mechanic. Mechanic confirmed issue. Diagnosis was misfire in #5 cylinder, confirmed initial compression upon startup (1 second) then compression loss and cylinder full of oil due to failed lifter. No previous issues prior to failure.
Other or unspecified, Engine, Fuel/propulsion system, Sep 19, 2026
Vehicle: 2020 GMC Sierra 1500 SLT VIN: 3GTU9DEL5LG340438 Engine: 6.2L V8, RPO L87 Mileage: approximately 129,854 miles My 2020 GMC Sierra 1500 equipped with the L87 6.2L V8 experienced an engine failure and has been diagnosed as needing an engine replacement. I am reporting this because my vehicle is equipped with the same L87 6.2L engine currently being investigated by NHTSA under Engineering Analysis EA25007 for engine failures occurring outside the scope of Recall 25V-274. My model year is not currently included in Recall 25V-274. However, EA25007 specifically addresses L87 engine failures occurring outside the existing recall population, including 2019–2024 GMC Sierra 1500 vehicles. GM also issued Preliminary Information bulletin PIP5900, “Diagnostic Tips for Seized Engine or Engine Noise,” applicable to 2019–2023 GMC Sierra vehicles equipped with the 6.2L L87 engine, which identifies possible crankshaft bearing failure. I am requesting that this engine failure be documented as part of NHTSA's ongoing investigation of L87 engine failures outside Recall 25V-274.
Engine, Sep 15, 2026
Timing in engine is going out at 150,000 miles
Power train, Electrical system, Engine, Sep 15, 2026
5/5/25 woke up back seat entire truck flooring soaking wet back glass cracked. 4/8/25 transmission went out 117,000 miles 7/3/25 exhaust leak and placed nox 1. 7/8/25 127551 mileage exhaust leak replace gaskets, belt , tensioner, and pulley, 6/8/2025 3 knock sensors replaced and replaced intake manifold.
Power train, Sep 14, 2026
Transmission shifting hard in first few gears and only 87,000 miles on Transmission.
Engine and engine cooling, Sep 14, 2026
The contact owns a 2020 GMC Sierra 1500. The contact stated that while driving approximately 55 MPH, the vehicle started losing power and decelerated. The check engine warning light was flashing with several unknown messages displayed. The vehicle was parked on the side of the road and later towed to the local dealer to be diagnosed. The contact was informed that the lifters, push rods, and camshaft had failed and needed to be replaced. The lifters, push rods, and camshaft were replaced, and the vehicle was repaired. The contact stated that approximately 6,900 miles later, the failure reoccurred. The vehicle was towed back to the local dealer, and the contact was informed that the engine crankshaft and connecting rods had failed and the engine needed to be replaced. The vehicle was not yet repaired. The failure mileage was 115,000.
Power train, Engine, Sep 9, 2026
Powertrain issues and a chassis issue that is extremely dangerous.Tailgate on rare occasions falls open by itself. There is a design flaw in the placement of the catalytic converters. The heat is burning up the fluid. I could not believe my eyes when I serviced the transmission. This is another shortcut by GM to save on the extra wiring needed for the oxygen sensors (2)in the converters and the two oxygen sensors downstream of the converters. There is plenty of room for the converters further down by the tail shaft to drive shaft connections. This is GM’s way of being cheap. Here’s the problem. The converters get way too hot. The fill plug for the transmission which is behind a low rent heat shield crumbled into my hands from excessive heat buildup. GM knows there is a problem with the fluid breaking down. Their bandaid answer is to use Mobil 1 fluid instead of the recommended Dexron 6. What needs to happen is a safety recall issued for the unwanted tailgate deploying all by itself. There needs to be a redesign in the exhaust system. The Transmission (8 Speed) has a catalytic converter exactly on both sides and the crossover pipe runs directly under the transmission sump pan. No wonder they are having issues with transmissions burning up. THIS IS A FIRE HAZARD !!! With the converters being so close to the exhaust manifolds, a leak from the engine or the transmission would be enough to ignite and possibly kill the occupants. All in the name of saving a few cents in wiring. Myself, I am a retired GM Mechanic. I started working at Sewell Cadillac in [XXX] in 1975. I have held the title of ASE Master Tech. Cadillac Master Tech. I have been a GM Shop Foreman and A GM Service and Parts Director in my Career. I retired from Federal Express as in charge of Fleet Maintenance and GSE(Aircraft Equipment). I have certifications from Mercedes, BMW, Toyota, Commander Loaders, Goodyear, and more. Given the right set of circumstances, it could end very badly. Dangerous Truck ! INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Engine, Sep 9, 2026
I was driving home with my wife. The engine just cut off. No power to the gas pedal. Luckily we were able to coast long enough to find a shoulder to pull off onto. Truck wouldn’t restart. Had to call a tow truck and have it towed to the Chevy dealership. The engine was already repaired once. Ref number 11696129. I just got the truck back and fixed again. So far I’ve had to pay for 2 tows and 2 repairs costing be about 3000 dollars. Both repairs have been done at a Chevy dealership.
Engine, Sep 8, 2026
I was driving on the highway at 70mph when out of no where my truck stopped running and I received a message warning to put the truck in neutral and restart the engine. It was very alarming being on the highway and this happening. I was unable to restart the vehicle so I had to coast and navigate us at high speed to the should of the highway. Since it was Labor day I had to sit for over 4 hours before getting a tow vehicle at 2am to tow my truck to [XXX] FLOW Buick GMC. They contacted me and told me that my engine had seized and that it was possible bearings or something that made it seize and I need a whole new engine. They quoted me 12,500. I have not done anything yet in repairs and I now contacted GM and submitted a Case #XXX. I notified them I am aware of the known issue and the GM service bulletin PIP5900. I am waiting for them to respond now. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Service brakes, Engine, Sep 7, 2026
Lifter failed due to AFM system. Cyl 8 misfire due to oil fouling. The onboard computer got confused and would not release the parking brake until repeated attemtps to release it. 5.3L V8 2020 model year 115250 miles. Isn't this the same problem as the 2021 and newer engines? 8spd transmission. AFM failure. 9k repair.
Engine, Sep 3, 2026
2020 GMC Sierra 1500 AT4, 3.0L LM2 Duramax. In service 08/13/2020. Five glow plug failures on five different cylinders in under 19,000 miles, all at one GM dealer, all part 24000504: Cyl 1, 10/21/2024, 38,650 mi, P0671, RO 13714, warranty. Cyl 6, 11/05/2024, 38,793 mi, P1330, RO 26665, warranty. Cyl 4, 11/29/2024, 39,683 mi, P133B, RO 57498, warranty. Cyl 3, 01/22/2026, 52,959 mi, P0673/P06C7/P133A, RO 100951, I paid $713.38. Cyl 2, 08/26/2026, 57,466 mi, P06C6/P0672/P1339, RO 115953, GM under N232430460. The first three came within 39 days and 1,033 miles. Every RO documents the same finding: high internal resistance in the plug, circuit tests good. The failure is internal to the plug. Glow plug failure on a diesel causes hard starting, extended cranking, no-start in cold weather, and startup misfire - risk of being stranded or unable to start. GM has documented this defect three times: PIP5762 (12/2020), TSB 22-NA-027 (2/2022), Special Coverage N232430460 (1/2024). All name an inadequate camshaft housing cover baffle plate weld, and all limit the remedy to cylinder 2. On the recorded walkaround for RO 115953 the tech stated my engine serial falls inside the affected population and my earlier failures were probably the same condition. GM replaced only the glow plug. The camshaft cover GM identifies as the cause is still installed; GM quoted me $5,100 to replace it at my expense. Four of five failures were on cylinders 1, 3, 4 and 6, outside that scope. If the bad weld passes oil into the PCV and intake path rather than only the cylinder 2 glow plug well, ingested oil would reach other cylinders. No RO shows anyone inspected the intake tract, charge piping, cooler, PCV separator, a removed plug, or a glow plug well. I ask ODI to examine whether the cylinder-2-only scope of N232430460 is under-inclusive, whether replacing the plug while leaving the cause installed is an adequate remedy, and whether repeated internal failure of part 24000504 warrants a recall.
Engine, Aug 29, 2026
Driving approximately 75mph on a local highway, my engine shut down with no warning, the screen said to shift into neutral to restart but nothing happened so I was stranded along the side of the highway and had to wait 2hrs for a tow truck in the middle of the night and the engine is currently locked up.
Power train, Vehicle speed control, Other or unspecified, Aug 26, 2026
This truck was bought brand new by my father. Around 38,000 miles it begin having issues with shifting which eventually got worse. When I searched google for issues many others on different pages have had the same issues. The shifting would be so rough it feels like you're being hit by another vehicle. This could cause accidents for anyone who cannot afford to fix these known issues by GMC. I was told today by my local dealership their transmissions for my specific truck is on backorder. Should that not indicate an issue when this truck is a 2020. But to my father having a stroke I was not able to handle this issue sooner as he was very ill for four years and passed last year. The truck was not the priority at the time.
Engine, Aug 26, 2026
Misfire on 2 cylinder, noise on start up diagnostic code P0300 P0302 P050 I was driving home and the engine started making a strange sound, vehicle would could no increase speed normally. The dealership did basic analysis from the onboard computer and did a compression test. Heavy knocking sound on passenger side of the engine. The issue happened on Aug 5th 2026. The issue is due to the AFM that causes the lifter to fail and dealership says I need a new engine $15787 or replace cam shaft $14530.
Engine, Aug 26, 2026
On XXX my GMC 6.2L Sierra 1500 Denali engine cutoff in Traffic and had to be towed. There was no indications prior to failure. Found out after replacing battery that the 400amp fuse blew and the engine seized. Vehicle was then towed to Hendrick Buick GMC dealer in [XXX] for repair. My engine has 49,500 miles but is out of warranty due to time. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Structure, Aug 26, 2026
I have a rear sliding window on the cab of my truck that leaks from both ends of the plastic guide. I noticed it when placing my young children in their car seats. I contacted my dealership and was informed the repair would cost $1500+ and not be covered by GM or warranty.
Power train, Engine, Aug 26, 2026
High pressure fuel pump went at 80k and now on my 2nd transmission under 100k miles this is absolutely absurd
Engine, Aug 25, 2026
Engine went into limp mode and engine is no longer good
Power train, Engine, Aug 24, 2026
The 5.3L Engine active fuel management failure problem. This known problem with the GMC motors was not disclosed by any dealerships or the manufacturer. While driving down the roadway, the truck had an engine malfunction and I was fortunate enough to be able to safely pull over. The check engine light activated and I took it to the dealer the next day. I was informed by the dealer that this was a known, common issue that GM was aware of but was not offering assistance. I had to pay $11,000 out-of-pocket because of this.
Engine, Back over prevention, Aug 24, 2026, crash
Piston 5 dropped compression to 120 the rest were 190-200. The engine failed therefore none of my parking assist sensors were working and I backed into a car because the truck was misfiring.
Power train, Electrical system, Engine, Aug 24, 2026
Our 2020 GMC SIERRA 1500 has suffered catastrophic systems and engine failure including the brakes multiple times for almost 4 years. It has happened in high traffic and on the interstate each time having to be coasted off of the road to come to a rolling stop. There have been nine repair attempts with GM dealers repeatedly stating the issues were repaired and returning our vehicle to us. We began making the CEO and Executive team aware of the potentially deadly safety hazards including the fact that I, [XXX] am disabled and power wheelchair dependent requiring a truck that can carry my power wheelchair. We have sent numerous emails to Ms. [XXX] and the Executive team numerous times informing them in detail, each time, of all issues involved. We started communicating via phone and email with customer care to no avail. All attempts at repair finally ended in complete engine failure leaving us with an estimate to replace the engine of over $13,000. We have also, submitted a detailed complaint to the Attorney General’s Office and after review were given the Case # TCP - XXX. I will attach the Complaint and Addendum sent to the Attorney General along with two of the emails sent to Ms. [XXX] and her team informing her of all issues with the truck. They took no action to actually help us get this truck off of the road knowing it was having catastrophic engine and system failure and that it had to be driven to transport a disabled power wheel dependent with severe medical issues and the medically necessary power wheelchair. I am also attaching the earliest OnStar Diagnostic notice of Engine, Transmission and Emissions system issues from May of 2023. The issues have remained the same from the beginning only worsening though my husband has only driven the truck in town on slower less busy streets learning how to make adjustments such as pumping the brakes and starting and stopping the truck to keep it going. My carrier is installed and yet it is undrivable. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Engine, Aug 24, 2026
I purchased my 2020 GMC Sierra 1500 AT4 with the L87 6.2L V8 new from a GMC dealer in March 2020 for $65,910 (VIN [XXX]). The truck has primarily highway mileage, very little towing, and has been well maintained. At 166,634 miles on [XXX], the truck developed a flashing check-engine light. The GMC dealer diagnosed “Cyl 3 lifter failure with camshaft damage” and determined that replacing the engine was preferable to repairing it because of the vehicle's mileage. The dealer installed a replacement OEM GMC engine and replaced both broken engine mounts. The replacement engine and installation cost $11,778. The replacement engine has subsequently required multiple repairs. At approximately 170,411 miles, the GMC dealer documented an exhaust leak that had occurred since the engine repair and a coolant leak from the upper radiator hose; both were repaired. At approximately 187,699 miles, the truck experienced overheating, coolant leakage, and loud engine-area noise. The dealer found that the water pump was coming apart and replaced the water pump and related components. I am reporting this vehicle because it is a 2020 Sierra equipped with the L87 6.2L engine and experienced catastrophic lifter/camshaft failure requiring complete engine replacement, followed by multiple engine-related repairs. I believe this history is relevant to NHTSA's investigation of L87 engine failures in earlier model years and warrants consideration when evaluating whether the known L87 engine defect extends beyond the vehicles currently covered by the recall. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Fuel/propulsion system, Aug 17, 2026
Gas fill door won’t stay closed