2021 Chevrolet Tahoe

On January 16, 2026, the Office of Defects Investigation (ODI) opened Recall Query RQ26001.  This investigation was opened to assess the remedy effectiveness of Recall 25V-274. ODI has received complaints alleging engine failure in vehicles after the recall remedy had been completed, whether that remedy involved an oil viscosity change or a complete engine replacement. General Motors (GM) issued Recall 25V-274 to address concerns of engine failure in the L87 engines produced between March 1, 2021 and May 31, 2024. GM cited the root cause as a supplier manufacturing and quality issue. GM’s recall remedy for Recall 25V-274 consisted of two different repairs, either an oil viscosity change or an engine replacement, based on the results of the remedy inspection procedure. ODI continues to receive reports of engine failures after the completion of the recall remedy. To date, ODI has received 499 complaints alleging post-remedy engine failure in vehicles subject to Recall 25V-274, 473 of which involved an oil viscosity change and 26 a complete engine replacement. Additionally, ODI has received 191 reports of L87 engine failures in engines produced after the production period cited in Recall 25V-274. GM reported receiving 6,953 complaints of post-remedy engine failure. ODI is opening this Engineering Analysisto continue investigating complaints of post-remedy engine failure. ODI is expanding the scope of this Investigation to include engines produced after the production period cited in the recall. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.

The Office of Defects Investigation (ODI) has received 1,157 reports of engine bearing failure failures in the L87 6.2L engine produced by General Motors (GM). Of the 1,157 reports received, 173 are outside of the scope of recall 25V-274. These engines are installed in Model Years (MY) 2019–2024 Chevrolet Silverado 1500 and GMC Sierra 1500, and 2021-2024MY Chevrolet Suburban and Tahoe, GMC Yukon/Yukon XL, and Cadillac Escalade/Escalade ESV vehicles. The subject engine failures were investigated as part of a Preliminary Evaluation (PE25001).  GM determined that these engine failures were due to multiple supplier manufacturing and quality issues. GM issued recall 25V-274 to address the supplier manufacturing and quality issues produced between March 1, 2021, and May 31, 2024. Based on the issuance of recall 25V-274, NHTSA has closed PE25001. ODI continues to receive a significant number of reports of engine failure in vehicles outside the scope of 25V-274.  This presents a potential safety risk that warrants further investigation.  ODI is opening this Engineering Analysis (EA) to further evaluate the scope and severity of the potential problem and to fully assess the potential safety-related issues of vehicles built outside the recall scope. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.

On January 16, 2026, the Office of Defects Investigation (ODI) opened Recall Query RQ26001.  This investigation was opened to assess the remedy effectiveness of Recall 25V-274. ODI has received complaints alleging engine failure in vehicles after the recall remedy had been completed, whether that remedy involved an oil viscosity change or a complete engine replacement. General Motors (GM) issued Recall 25V-274 to address concerns of engine failure in the L87 engines produced between March 1, 2021 and May 31, 2024. GM cited the root cause as a supplier manufacturing and quality issue. GM’s recall remedy for Recall 25V-274 consisted of two different repairs, either an oil viscosity change or an engine replacement, based on the results of the remedy inspection procedure. ODI continues to receive reports of engine failures after the completion of the recall remedy. To date, ODI has received 499 complaints alleging post-remedy engine failure in vehicles subject to Recall 25V-274, 473 of which involved an oil viscosity change and 26 a complete engine replacement. GM reported receiving 6,953 complaints of post-remedy engine failure. ODI will close this RQ and continue to investigate complaints of post-remedy engine failure for Recall 25V-274 as part of an Engineering Analysis (EA26005). To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.

On January 16, 2025, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE25001 after receiving complaints and field reports concerning engine failures in MY2019-2024 GM’s full-size truck and SUV T1XX platform equipped with the L87 6.2L V8 engine. These complainants alleged engine bearing failures resulting in knocking and growling noises from the engine’s bottom end and in some cases more severe consequences such as broken connecting rods leading to engine damage, or engine failure. If the engine fails during vehicle operation, the vehicle will lose propulsion, increasing the risk of a crash. On April 24, 2025, GM issued recall 25V-274 to address the concern with L87 engines produced between March 1, 2021, and May 31, 2024.  GM cited the root cause as a supplier manufacturing and quality issues. GM’s  recall remedy will be either an oil change to an oil with a different viscosity or engine replacement depending on the results of the remedy inspection procedure. To date, ODI has received 1,157 allegations of engine bearing failure. GM submitted 55,464 reports in total, with 29,752 unique VINs. ODI continues to receive allegations of L87 engine failures which fall outside of the scope of recall 25V-274. Based on GM’s recall, ODI will close this PE. NHTSA will continue to investigate complaints of engine failure outside the scope of recall 25V-274 as part ofEngineering Analysis (EA25007). To review the ODI reports cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.

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

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving at various speeds uphill, the vehicle made a loud clunking sound while downshifting. While driving 70 MPH on one occasion, and while driving 20 MPH on another occasion, the vehicle made a loud clunking sound while downshifting and lost motive power, prompting the driver to pull over to the side of the road. The message "Reduced Acceleration - Drive with Care" was displayed, and the check engine warning light illuminated following the failure. The vehicle was restarted but the warning light remained illuminated. The vehicle was taken to a local dealer, where it was diagnosed and determined that the transmission control valve body and a separator plate or spacer needed to be replaced. The contact associated the failure with TSB: 22-NA-258; however, the VIN was not included. The vehicle was being repaired. The manufacturer was notified of the failure by phone and offered partial financial assistance. The failure mileage was approximately 76,000.

NHTSA ID

11766359

Incident

Jun 1, 2026

Mileage

76,000 mi

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

On September 19, 2026, while traveling approximately 30 mph, the vehicle experienced a sudden, hard shift. The check-engine light then illuminated. I pulled over as soon as it was safe to do so. After stopping, the vehicle would not shift into reverse and entered limp mode. The transmission malfunction created a safety risk because the vehicle’s operation and available gears became restricted unexpectedly while it was being driven. The loss of reverse also prevented the vehicle from being maneuvered normally. The vehicle was not driven after the incident and was towed from the location. The vehicle and affected components are available for inspection upon request. At this time, the vehicle is awaiting inspection and diagnosis to determine the exact cause of the transmission malfunction.

NHTSA ID

11765656

Incident

Sep 19, 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

I received an automated message from the vehicle stating to service the safety restraint system. I took the car to the local dealer and they ran a diagnostic review. There is a TSB for the vehicle and they say that the problem is coming from the overhead console part number 86575239. This part is not available anywhere. I contacted General Motors and requested assistance. All they have done is escalate it to the parts delay team. When I called today, all they say is they do not have any information available. They can’t even say when the part will be in stock. The dealership was unable to say that the airbag system would work as required or not. The car is unusable due to the passenger air bag system fault.

NHTSA ID

11764050

Incident

Aug 2, 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

This preliminary information communicates diagnostic tips for air leveling suspension system.

This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.

This PI provides a diagnostic tip when fuse F4DR is opening and dealerships are to inspect the wiring at the center console lid.

This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues

This PI Communicates information to ensure Memory Recall is enabled to ensure memory mirrors return to set position after curbview assist is used.

This PI provides diagnostic tips for diagnosing electric trailer brakes issues.