2021 Chevrolet Tahoe: misfire or rough idle

Filed Nov 4, 2026 · Engine · NC

The engine lifters have failed twice in our 2021 Chevy Tahoe. The first time was at 13k miles and the second time happened at 100k miles. Both times the failures put my family in an unsafe situation and almost led to a multicar accident. This is a known issue that multiple people report online in the 2021-2024 Chevy Tahoe. The first time the lifters went out, I had just purchased the car. I only had 13k miles on the vehicle when it began shaking and jumping while at a stop. As I drove further the car began violently shaking and making backfire noises. I had to stop the vehicle in the road, as there was no pull off. We had the vehicle towed to the dealership and they replaced them under warranty. They said the lifters had gone out and they resolved the issue. I asked at that time if this was normal and if it could happen again. I was told it was not normal and it was not something that should be happening on a new vehicle, but they had fixed the issue and felt comfortable that it was resolved. The second time happened just a couple days ago. There was no warning or lights that came on before the incident. My family was in the fast lanes on I-77, going about 70 mph, and the car began misfiring. It was making noises that grew loud and then the car began violently shaking. We were forced to pull off the interstate abruptly. This put us in an extremely unsafe situation. The car is only at about 100k miles and 5 years old. We had the car towed to a Chevy dealership and were told the lifters went out again. This time damaging the cam shaft as well. It is a $6,600 repair, as the car is out of warranty now. This issue should not be happening, especially not multiple times, on a car that is only 5 years old. I believe there is a defect. When there are no warning lights that alert you to a potential issue, this causes an extremely unsafe situation for drivers, passengers, and surrounding vehicles.

Filed Sep 22, 2026 · Driver assistance, Engine · CA

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)

Filed Jun 10, 2026 · Engine · TX

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 the federal safety agency 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.

Filed May 11, 2026 · Engine · CO

Engine has developed a miss and has check engine code P0300 random misfires. There are subcodes pending of P0011 and P0016 indicating Crank and Cam misalignment. This has all the classic signs for a failing engine. I am taking this truck in for the GM Picoscope test, the oil was changed to 0w40 mobile one supercar oil approx. 2,800 miles ago when the truck was under Powertrain warranty. I will preform a Blackstone oil test to determine if there is abnormal engine wear. My truck is not in the vin. recall range.

Filed Apr 28, 2026 · Engine · TN

Urgent: Engine Failure Following Recent Service – 2021 Chevrolet Tahoe To Whom It May Concern, I am writing to formally request assistance and an investigation regarding a serious engine failure involving my 2021 Chevrolet Tahoe. In July 2025, I paid out of pocket to have the lifters and camshaft replaced on this vehicle. More recently, while traveling, the vehicle broke down and was taken to Uebelhor Chevrolet, where the valve body in the transmission was replaced. After picking the vehicle up from Uebelhor Chevrolet, the vehicle broke down again approximately one hour later while in Henderson, Kentucky. At that time, the engine began smoking, running rough, and misfiring. I checked the oil level during the incident and found it to be extremely low on the dipstick (I have photographic evidence of this condition). The vehicle had to be towed to Kate Faupel Chevrolet for further inspection. I was then informed that the engine has a dropped lifter on cylinder #8 and possible camshaft damage. Given the following factors: Recent out-of-pocket lifter and camshaft replacement (July 2025) Immediate failure shortly after leaving a Chevrolet dealership Extremely low oil level observed at the time of breakdown (with photo documentation) Diagnosis consistent with potential oil starvation and internal engine damage I am requesting that General Motors conduct a full review of this situation to determine responsibility. This raises serious concerns about a potential defect, improper prior repair, or a service-related issue that resulted in catastrophic engine damage. At this time, I am not authorizing repairs until liability is determined. I am requesting: A formal case review and investigation Assistance with repair or full engine replacement Guidance on how this situation will be resolved This incident created a significant safety concern, as the vehicle became disabled shortly after leaving a dealership during travel. Please contact me as soon as possible to discuss next steps

Filed Apr 12, 2026 · Driver assistance, Engine · CA

The component at issue is the engine, which suffered a sudden and catastrophic failure due to unknown causes. At no time prior to this incident were there any warnings, symptoms, or indications of an underlying mechanical defect that would have allowed for preventative action. While operating the vehicle on the highway with my family present, multiple warning indicators activated simultaneously, including a blinking check engine light, traction control light, ESC warning, and a forward collision warning. Immediately thereafter, the vehicle experienced a rapid and significant loss of power accompanied by a loud and persistent engine knocking noise, rendering the vehicle unsafe to operate and placing the occupants at risk. It is important to emphasize that traction control and ESC systems are not causally related to an engine misfire condition, further supporting that this event was abrupt and not part of a progressive or diagnosable issue. A diagnostic scan performed at that time identified a misfire in cylinder 1. Upon delivery of the vehicle to the dealership for inspection, it was determined that the engine had suffered complete internal failure and was deemed “blown.” This finding confirms the occurrence of a catastrophic mechanical breakdown. Based on the sudden onset, absence of prior warning, and severity of the failure, there is no reasonable basis to attribute this condition to normal wear and tear, operator misuse, or neglect. Rather, the facts support the conclusion that this was the result of a latent defect or internal mechanical failure beyond the operator’s control. Accordingly, this matter should be addressed under applicable warranty coverage or consumer protection standards.

Filed Apr 7, 2026 · Engine · 100,000 miles · NC

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving approximately 45 MPH, the check engine warning light illuminated, and the message “Reduced Acceleration - Drive Safely” was displayed. The vehicle then started shaking abnormally. The contact pulled into a nearby parking lot, turned off the vehicle, and waited for a while before restarting the vehicle. After restarting the vehicle, the warning lights remained illuminated, and the vehicle continued to shake abnormally. The vehicle was taken to Auto Zone, where a certified mechanic diagnosed the vehicle and determined that there was a bent rod inside the engine. The vehicle was not repaired. The vehicle was taken to the dealer, who confirmed the diagnostic result and that the failure was causing additional damage to the crankshaft. The dealer determined that there was a misfire in the engine and that the valve lifter was malfunctioning. The contact was informed that the lifter and the camshaft needed to be replaced, and the engine needed to be repaired. The vehicle was not repaired. The contact researched and became aware of the federal safety agency Campaign Number: 25V274000 (Engine and Engine Cooling); however, the VIN was not included. The manufacturer was informed of the failure and confirmed that the VIN was not included in the recall. The contact was referred to the dealer to inquire about a Goodwill Repair for which the contact could be reimbursed if the VIN was later added to the recall. The manufacturer referred the contact to the federal safety agency Hotline to report the failure. The failure mileage was approximately 100,000.

Filed Feb 11, 2026 · Engine · 93,000 miles · TX

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while his wife was driving out of the driveway and driving approximately 20 MPH, the driver became aware of an abnormal flapping sound that became louder as the vehicle accelerated. Additionally, the contact stated while his wife was driving approximately 60-65 MPH on another occasion, the check engine warning light illuminated. The driver pulled over to the side of the road. The vehicle was towed to the residence, where a mobile independent mechanic diagnosed the vehicle with a misfire in cylinder #8. The mechanic determined that both sides of the engine lifters, the gaskets, and other unknown parts needed to be replaced. The vehicle was not repaired due to the cost. The dealer and the manufacturer were not contacted. The vehicle warranty company was contacted and informed the contact that the vehicle was not covered under warranty. The failure mileage was approximately 93,000.

Filed Nov 20, 2025 · Engine, Transmission · GA

I am writing to formally document serious engine defects I have experienced with my 2021 Chevrolet Tahoe equipped with the 5.3L L84 V8 engine. 1.Crankshaft Failure: My Tahoe suffered a catastrophic crankshaft failure that required major repair/replacement. I am aware that GM has recalled certain vehicles equipped with the 6.2L L87 engine for crankshaft and rod-bearing defects. Based on my experience, the same or a very similar defect has also occurred in my 5.3L engine, which is currently not included in that recall. 2.Valve Lifter Failure: In addition, my vehicle has suffered from valve lifter collapse—a well-documented problem in 2021–2022 GM trucks and SUVs with both the 5.3L and 6.2L engines. This caused severe misfiring, drivability issues, and expensive repair needs. Why this is a concern: •Both failures occurred well before what would be expected of a modern engine. •The crankshaft failure raises a safety risk: sudden loss of propulsion while driving could lead to accidents. •The lifter issue is widely reported by other owners and has been the subject of GM service bulletins. •Taken together, these problems suggest systemic defects in the 2021 Tahoe’s 5.3L engine that have not been adequately addressed by GM. Requested Action: •I ask GM to extend recall and warranty coverage to include the 5.3L L84 engine in addition to the 6.2L L87. •I ask the federal safety agency to consider investigating whether the scope of the current 6.2L recall should be broadened to include 5.3L engines, given failures like mine. •At minimum, I request assistance in covering repair/replacement costs for both the crankshaft and lifter defects, which are clearly not due to normal wear and tear. Vehicle details: •Year/Make/Model: 2021 Chevrolet Tahoe •Engine: 5.3L V8 L84

Filed Nov 13, 2025 · Engine · 143,000 miles · VA

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving at 70 MPH, the vehicle failed to accelerate as intended while depressing the accelerator pedal. The message “Service Electronic Stability Control" was displayed, and the traction control warning light and the check engine warning light were illuminated. The failure persisted while driving, and the vehicle failed to exceed 50 MPH. The vehicle was taken to an independent mechanic who diagnosed that the lifters had failed, the camshaft had failed, and there was a misfire in cylinder #5. The vehicle was not repaired. The vehicle was towed to the residence and had not been driven since. The manufacturer was not notified of the failure. The failure mileage was approximately 143,000.

Filed Nov 3, 2025 · Engine · 87,893 miles · TX

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving at an undisclosed speed, several unknown warning lights illuminated. In addition, the contact noticed an abnormal ticking sound. The vehicle was towed to an independent mechanic, where the vehicle was diagnosed with a misfire in cylinder #7. The independent mechanic checked the spark plugs and other unknown parts for failure; however, there was no evidence of a failure. The contact was informed of a valve lifter failure. The contact was informed that the valve lifter and possibly the push rods and camshaft needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure but provided no assistance. The contact referenced Technical Service Bulletin: N212353840; however, the VIN was not included. The contact was advised to contact the federal safety agency Hotline to report the failure. The failure mileage was approximately 87,893.

Filed Sep 2, 2025 · Engine, Transmission · TN

I am writing to formally document serious engine defects I have experienced with my 2021 Chevrolet Tahoe equipped with the 5.3L L84 V8 engine. 1.Crankshaft Failure oMy Tahoe suffered a catastrophic crankshaft failure that required major repair/replacement. oI am aware that GM has recalled certain vehicles equipped with the 6.2L L87 engine for crankshaft and rod-bearing defects. oBased on my experience, the same or a very similar defect has also occurred in my 5.3L engine, which is currently not included in that recall. 2.Valve Lifter Failure oIn addition, my vehicle has suffered from valve lifter collapse—a well-documented problem in 2021–2022 GM trucks and SUVs with both the 5.3L and 6.2L engines. oThis caused severe misfiring, drivability issues, and expensive repair needs. Why this is a concern: •Both failures occurred well before what would be expected of a modern engine. •The crankshaft failure raises a safety risk: sudden loss of propulsion while driving could lead to accidents. •The lifter issue is widely reported by other owners and has been the subject of GM service bulletins. •Taken together, these problems suggest systemic defects in the 2021 Tahoe’s 5.3L engine that have not been adequately addressed by GM. Requested Action: •I ask GM to extend recall and warranty coverage to include the 5.3L L84 engine in addition to the 6.2L L87. •I ask the federal safety agency to consider investigating whether the scope of the current 6.2L recall should be broadened to include 5.3L engines, given failures like mine. •At minimum, I request assistance in covering repair/replacement costs for both the crankshaft and lifter defects, which are clearly not due to normal wear and tear. Vehicle details: •Year/Make/Model: 2021 Chevrolet Tahoe •Engine: 5.3L V8 L84