2021 Chevrolet Tahoe Engine Problems

The vehicle suffered complete internal engine failure due to a snapped timing chain on startup. The vehicle turned over via the starter motor but failed to start. A professional diagnosis confirmed the broken timing chain caused extensive valve-to-piston damage, requiring a full engine replacement. This failure appears to be a direct consequence of the known 6.2L L87 V8 engine crankshaft and connecting rod manufacturing defects. Severe mechanical resistance or violent rotational harmonics at the crankshaft level place un-engineered stress on the timing drive system, causing the chain to snap under startup torque. All broken components are preserved and available for inspection. The defect creates a severe risk of sudden, total loss of propulsion while driving. Had the compromised timing chain snapped at highway speeds rather than on startup, it would cause immediate engine seizure, a sudden loss of power steering, and a loss of power brake vacuum assist. This leaves the driver unable to accelerate or safely steer out of active traffic, creating an extreme risk of a high-speed crash.The broken timing chain and total engine destruction were officially diagnosed and confirmed by professional automotive repair technicians.The damaged components have been inspected by independent repair representatives. The vehicle has not yet been inspected by General Motors because this specific VIN is excluded from the current recall scope. There were no warning lamps, check engine lights, or diagnostic trouble codes (DTCs) prior to parking the vehicle, and no outward symptoms of severe engine stress were present until the complete no-start failure.

NHTSA ID

11766558

Incident

Aug 29, 2026

On [XXX], while driving near Mammoth Mountain, California (Highway [XXX]), the vehicle suffered a sudden, severe engine malfunction. The engine began misfiring violently, accompanied by a loud, mechanical clacking noise, and experienced an immediate loss of propulsion power. This mechanical failure left my family—including young children—completely stranded on the side of a mountain highway in a secluded wilderness area with dropping temperatures (39°F) and active local wildlife Because the vehicle could not safely maintain highway speeds or generate sufficient power, it created an immediate and severe traffic safety hazard, forcing us to secure emergency transport for the vehicle. Which took 4hours for someone to come out to the secluded hwy on a holiday weekend. Dealership Diagnostic Findings A formal inspection conducted by a certified General Motors dealership (Michael Hohl Motor Company) confirmed the following: Symptoms: Gas engine diagnostic confirmed "Misfire, and clacking noises coming from passenger side of the motor." Diagnosis: Cylinder Head / Valve / Lifter / Lash Adjuster failure. The dealership documented a collapsed lifter and recommended a complete engine tear-down to inspect lifters and pushrods for wear or bending. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11766224

Incident

Sep 4, 2026

2021 Chevrolet Tahoe – Unexpected Shutdown/Restart While Stopped On two separate occasions, my 2021 Chevrolet Tahoe has unexpectedly appeared to shut down while I was stopped with my foot on the brake. The vehicle is equipped with Auto Stop/Start, and initially the event seems like a normal Auto Stop. However, instead of a normal engine Auto Stop/Start cycle, the vehicle appears to shut down or reset more completely. The event is jarring, and the power door locks lock/unlock as the vehicle shuts down and restarts. The vehicle subsequently restarts and I have been able to continue driving. This has now occurred twice while stopped. I am concerned that the vehicle may be experiencing an unintended stall, loss of electrical power, or another malfunction rather than normal Auto Stop/Start operation. I checked my VIN through NHTSA and it does not currently show an open recall. I am aware that certain 2021 Chevrolet Tahoes have previously been recalled for a condition that could result in an engine stall, although my VIN does not appear to be included in that recall population.

NHTSA ID

11764299

Incident

Sep 15, 2026

The number 7 DFM lifter failed and is suspected of failing due to the Active Fuel System. The vehicle is currently at the dealership where it was diagnosed and is awaiting replacement parts that are on GMC back order for a month or longer. The vehicle started shaking on 8/25/26 when idle and the following warning lights were visible: AVS, traction control, and ECU.

NHTSA ID

11764249

Incident

Aug 25, 2026

DFM (Dynamic Fuel Management) system failure causing collapsed lifters, oil consumption, and complete engine failure. To repair our vehicle it will require a complete engine replacement. This has been a known issue with GM and yet there has been no recall to fix the issue. Now our engine must be replaced.

NHTSA ID

11763919

Incident

Sep 10, 2026

Total engine failure. No warning lights shown and vehicle had been checked numerous times and reported as just fine.

NHTSA ID

11762682

Incident

May 1, 2025

Engine failure Transmission failure

NHTSA ID

11761241

Incident

Oct 2, 2025

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving approximately 70 MPH, the message "Service ESC" was displayed, and the check engine, traction control, and Forward Collision Avoidance warning lights were illuminated. The vehicle started shaking and then lost power. The vehicle was pulled over to the side of the road, parked, and then turned off. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was 118,000.

NHTSA ID

11761231

Incident

Aug 31, 2026

Mileage

118,000 mi

The lifters are tapping on my vehicle and the engine also has a shutter to it. I am also not getting 5000 miles per oil change by 5000 miles my vehicle is showing add engine oil and is taking 2qts to get it back showing on the oil stick.

NHTSA ID

11760686

Incident

Aug 28, 2026

My vehicle had a pop and loss of power on the highway. After pulling over, I did not have a check engine light but did connect my code reader and found a P308. I felt unsafe to drive so I had it towed to a shop. I later found out the DOD system or lifter on valve #8 has failed and needs replacement. Factory recommends oil change at every 7k miles, I did them at 4K. My oil pressure was up to par with the small window of real time allowable oil pressure. The design was great on paper but one of the worst engines GM has ever made. I sincerely hope there is enough people complaining about these 2021 GM 6.2 & 5.3 engines!!

NHTSA ID

11760499

Incident

Aug 3, 2026

Engine ceased to run. Two rods bent. No power. All engine lights on. Good oil pressure and oil level. Tahoe towed back to Simi Valley Chevrolet for engine replacement.

NHTSA ID

11760482

Incident

Nov 13, 2025

When vehicle is idling the cabin shaking/vibrating. When engine is warm the sound of engine goes away and when it is cool the sound and vibrating comes back.

NHTSA ID

11759492

Incident

Aug 18, 2026

Nearly new Chevrolet Tahoe in 2021 with less than 4,000 miles had an engine failure due to defective valve lifters that required a significant repair and lengthy out of service period (replaced valve lifters in one bank). Now in 2026 the same vehicle's engine has failed for the same reason and the engine needed to be replaced.

NHTSA ID

11759036

Incident

May 1, 2026

6.2L engine failure. Camshaft and lifters. My [XXX] wife ([XXX]) was driving and it shut off going down the highway. It is at my local Chevrolet dealer getting repaired. No warnings. No engine light. Vehicle has 88,000 miles on it, I purchased it April 22, 2026 with 84,700 miles on it. My Chevrolet App says there are no issues with the vehicle..it’s in pieces at the dealership. I had higher standards for a high country. Always owned Chevrolets. May be my last one. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11758758

Incident

Aug 14, 2026

Engine failure of the 6.2L L87. Was 12 hours from home with my family on vacation in Colorado cruising up a 4 lane mountain highway about 700 yards from entering [XXX] thru the mountain and the engine started screaming and knocking. Thank the lord there was a way I could quickly steer my vehicle and family off the 65 mph hwy. Engine had recently passed the recall inspection test. “3,000ish miles ago” dealership confirmed engine failure and it’s sitting in cooorado waiting for a replacement engine. I believe this will be the 3rd engine now in my car. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11758674

Incident

Aug 5, 2026

While at a drive thru, my 2021 Chevy Tahoe High Country experienced a total failure with no advance warning where the engine shut down and would not restart despite what appeared to be good electrical power. We tried to jump start the vehicle with both another vehicle as well as a AAA power pack with no luck. The vehicle was not movable and had to be towed using a lift truck to the dealer. The dealer performed an analysis, reproduced the problem, and determined that the engine failed due to a spun bearing despite no documented codes from the analysis. In performing research, this failure appears identical to NHTSA Campaign 25V274 / GM number N252494000 however the car has been deemed to not be covered with mileage at 139,300.

NHTSA ID

11754638

Incident

Jul 23, 2026

The engine in my 2021 Chevrolet Tahoe High Country equipped with the 6.2L V8 (L87) experienced a catastrophic failure. While driving, the vehicle suddenly lost power, displayed a “Service ESC” warning, illuminated the check engine light, and unexpectedly shifted into Neutral. After stopping the vehicle, it would not restart. The dashboard would illuminate, but the engine would only produce a faint clicking sound and would not crank. The vehicle was towed to a Chevrolet dealership, where it remains available for inspection. How was your safety or the safety of others put at risk? This failure occurred while I was driving, causing an unexpected loss of power and propulsion. The vehicle became disabled without warning, creating a significant risk of being struck by surrounding traffic. Losing the ability to accelerate or safely maneuver a full-size SUV in traffic placed both me and other motorists at risk of a serious crash. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. The vehicle was towed to an authorized Chevrolet dealership, Crews Chevrolet. The dealership confirmed that the engine had catastrophically failed and advised that it qualified for replacement under General Motors’ special coverage program for the 6.2L L87 engine. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Yes. The vehicle has been inspected by an authorized Chevrolet dealership. General Motors has authorized replacement of the engine under its special coverage program. No police report was filed because there was no collision.

NHTSA ID

11752953

Incident

Jul 20, 2026

DATE: 06/17/2026 The engine shuts off without warning while I am driving, recurring roughly every 10 miles. When it stalls, the dashboard and electrical accessories stay on, but the vehicle loses motive power, along with power steering assist and power brake assist, which is extremely dangerous at road speed and in traffic. This began immediately after dealer service completed on 6/18/2026. During that visit the dealer performed two safety recalls (N252494000, the "L87 Engine Loss of Propulsion" PicoScope inspection with oil change; and N252510321, ECM software reprogramming) and a valve lifter replacement that required removing both cylinder heads. The vehicle was running and fully drivable when I dropped it off, and was returned stalling repeatedly while driving. It never did this before the service. At first the engine would not restart after stalling. The dealer replaced the starter; it now restarts but continues to stall every ~10 miles. A dealer diagnostic scan recorded numerous "Lost Communication" codes across nearly all control modules, plus control-module input-power codes showing low voltage and power-circuit correlation faults (e.g., U3505, U3018, U3007) and an active loss-of-communication code for the power steering module — consistent with an intermittent loss of electrical power or ground affecting engine control. The engine passed the recall's connecting-rod/crankshaft (PicoScope) inspection, so this is not the recalled bearing failure mode. The vehicle is currently at the dealership and is undrivable. The dealer has ordered a new engine and apparently also a new radiator for reasons unknown. No crash or injury has occurred to date, but the vehicle lost power while on the freeway at speed multiple times. A GM customer assistance case is open. Repair orders and the diagnostic scan are available on request.

NHTSA ID

11747941

Incident

Jun 18, 2026

After a car wash, the car started to smoke out of a tail pipe, down shifting hard, car was shaking while running in park in the driveway- so we took it right to Chevy Turnersville, and they are now saying the whole engine is internally damaged ( not by the carwash) and the whole engine needs to be replaced. The trucks warranty just expired in Feb, the car ran perfectly fine before this. I dont understand how an engine just stops working this fast and out of no where. We took very good care of this truck. Oil changes every time we needed, new tires, new alignment, the mile recommendations, everything! and this happens out of no where. It will now cost $12,000 to repair this which we do not have. Please help and explain this

NHTSA ID

11747386

Incident

Jun 26, 2026

The engine's Dynamic Fuel Management (DFM) lifter failed and damaged the camshaft at around 70,700 miles. The broken components are available for inspection upon request. This failure put occupants at risk because the vehicle suddenly lost power, began shaking violently, and could not accelerate safely in traffic. This unexpected loss of propulsion created an immediate collision hazard. The problem was officially diagnosed and confirmed by a repair service center. It has not been inspected by police or insurance representatives. There were no advance warning signs. At the exact moment of the failure, the check engine light started flashing, the car began shaking heavily, and the engine made a loud knocking sound.

NHTSA ID

11747364

Incident

Jun 15, 2026

2021 Chevy Tahoe with 6.2 engine (VIN: [XXX]) has been experiencing severe oil consumption, and making odd noises during operation. All while NOTshowing ANY recalls for the issue. Although there's an active recall/investigation into the 6.2 L87 engine, which my vehicle has. I've been having Valvoline document the severe oil consumption during oil changes per manufacturer specs. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11746967

Incident

Jun 25, 2026

We have a 2021 Chevy. Tahoe, and we just had an inspection done because a light kept coming on saying that our engine might fail. The shop initially said it needed cam shaft replacement, but now are saying the entire engine needs to be replaced. The care has ~ 67,000 miles on it and is 5 years old.

NHTSA ID

11746218

Incident

Apr 10, 2026

The contact's husband owns a 2021 Chevrolet Tahoe. The contact stated that while her husband was driving at an undisclosed speed, the vehicle shuddered and experienced a loss of drive power. A message to turn on the vehicle was displayed. The contact's husband coasted the vehicle to the side of the road and attempted to jumpstart the vehicle, but the vehicle failed to restart. The vehicle was towed to the dealer, who determined that the engine had seized and the crankshaft had failed. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 25V274000 (Engine and Engine Cooling); however, the VIN was not included in the recall. The manufacturer was made aware of the failure and advised the contact to file a complaint with the NHTSA Hotline. The failure mileage was approximately 130,000.

NHTSA ID

11743739

Incident

Jun 3, 2026

Mileage

130,000 mi

While driving my 2021 Chevrolet Tahoe, the check engine light illuminated. Shortly thereafter, the engine began shaking severely and I heard clicking and popping noises from the engine compartment. The following morning, the vehicle was barely operable, shaking excessively and unable to properly reverse. Due to the unsafe condition, I had the vehicle towed to the dealership. The dealership diagnosed a failure involving all 8 lifters on one side (bank) of the engine, requiring extensive engine repairs. My vehicle has approximately 74,000 miles, which I believe is low mileage for such a significant internal engine failure. The symptoms included severe engine vibration, misfiring, loss of performance, and the potential for loss of power while driving. This is not the first major failure I have experienced with this vehicle. In approximately April 2023, when the vehicle had about 32,000 miles, it unexpectedly shut off while I was reversing in a roadway. The dealership diagnosed a failed fuel pump control module (fuel pump modulator). Similar failures were later identified in recalls and corrective actions affecting other GM vehicles. I am concerned that my vehicle has experienced multiple failures involving components that appear to be associated with known issues affecting GM vehicles, yet my Tahoe was not included in applicable recalls. These failures created significant safety concerns, including unexpected engine shutdown, loss of vehicle operation, and potential loss of power while driving. I respectfully request that NHTSA investigate whether my 2021 Chevrolet Tahoe vehicles should have been included in existing and future safety recalls related to these defects and other known defects that GM vehicles are experiencing with the motor, transmission and other parts. Note: No invoice is available yet as I am seeking GM assistance due to no warranty status. Estimated repair cost from dealership is up to $8,900.

NHTSA ID

11743348

Incident

Jun 7, 2026

My wife was stopped at a stop light traveling west from and appointment. When the light turned green she moved her foot from the brake to gas when all of the warning lights. It happened at the worst time possible during rush hour and we were fortunate that she was not hit by traffic. After the police arrived to help re direct traffic and wait for a tow truck, we found coolant spilling underneath the engine towards the rear of it. Towed to local repair shop, they inspected and found the engine had a catastrophic failure. Likely related to the current recall for the 6.2l V8 engine installed in this Tahoe.

NHTSA ID

11740788

Incident

May 28, 2026