Based on dealer inspection, oil was found sitting on top of the #2 piston, and you-??ve indicated the failure is originating from the bottom end of the engine-?"likely involving piston, ring, or cylinder wall damage. Combined with the stored P050D, P0300, and P0302 codes, this represents a clear internal mechanical failure. Vehicle is currently at the dealership. Mechanical failure while driving the vehicle. Sensor light for service ESC and service traction control both showed as the failure was occurring.

- Saint Augustine, FL, USA

While driving and turning left and right, and while cold and turning It does a grinding/groan noice, and recently while driving it did that, and It started losing speed and the grinding worsening and I was losing control of the vehicle. Putting the vehicle in Auto makes the groan/grind worse.

- Isabela, PR, USA

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 NHTSA 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

- Jackson, GA, USA

The rear differential makes a rubbing or humming noise when turning left/right at slow speed especially when it-??s cold.

- Plantcity, FL, USA

My 2021 Chevrolet Tahoe recently displayed a warning message that said -??Service Transmission -?" May Not Be Able to Shift Soon.-?? The message appeared at approximately 132,754 miles. Since then, I-??ve noticed delayed and rough shifting between gears. The vehicle still drives and shifts into gear, but the message and behavior are concerning. I have an appointment scheduled for a diagnostic inspection on Tuesday, which was the earliest available. I have not yet received a confirmed diagnosis, but I-??ve seen that many other 2021 Tahoe's and similar GM vehicles have experienced the same transmission problem and were included in recalls. My vehicle-??s symptoms match those reports, though my VIN was not included. This situation makes me nervous because I drive with my four children daily. Even though the vehicle hasn-??t completely lost the ability to shift, a sudden failure while driving could put my family and others on the road at risk. The warning itself suggests a potential failure is coming soon. The vehicle has been properly maintained and has not had prior transmission work. I-??m reporting this because it appears to be part of a larger pattern that should be investigated to determine if more vehicles need to be included in GM-??s existing transmission recall.

- West Jordan, UT, USA

On the morning of 1 Oct, I had left the house here in Cedartown GA to head to a meeting in Atlanta with a customer. I had started the truck 15 minutes before departing just as we have always done to our vehicles over the years to allow them to warm up properly. I departed Doyle Rd onto Hwy 27 South heading towards interstate 20. About 15 miles from the house I was at a steady cruise speed of 45 MPH, no traffic, acceleration or deceleration and the stability control system light came on, one second later the engine light came on and the engine all of a sudden started making a loud grinding and clunking noise. I was on the inside lane so let the car pass next to me and started to pull over onto the shoulder of the road. I immediately shut off the truck, popped the hood and got out to inspect what might have happened. There was no smoke, I checked all the fluids and all were at the normal ranges. The engine oil was at its full mark as well. The oil was just changed a month early and still of the same color as it was new. After checking, I got back on the truck, attempted to start and it ran for a few seconds then I immediately shut it off after hearing again the loud noise. A Polk county police officer stopped to check on me and offer assistance as well as some tow companies to call. Eventually after about at hour a tow truck showed, we tried to momentarily start the vehicle so it could be put in neutral but the engine had locked up. I-??m glad I got off the road when I did, otherwise I feel I could have been driving and experienced that sudden lock up and loss of control which could have been a serious accident with log trucks up and down that highway all day long. This vehicle is my wife-??s primary vehicle and always has been maintained to a T just like all of our GM vehicles have. My daughter just graduated and drives our passed down 2005 Tahoe with over 300k miles that we bought in 2006. This has never happened to us and I feel it is a serious safety issue on the 6.2

- Cedartown, GA, USA

I have a 2021 Tahoe that while circling a parking lot at my son's football practice. The Tahoe's emergency came on and the Tahoe abruptly stopped. A checked engine light came on. The Tahoe wouldn't release the emergency brakes. I was finally able to get it released. I took the vehicle to a transmission shop because I plugged OBD scan tool on it. It had two transmission codes. One generic and one for the vavle body. The transmission shop said they have had lots of Tahoes with the vavle body's going out. They told me about N242454441. I called Chevrolet and they advised me that wasn't for my Tahoe. I asked why and they said they don't know. If this is effecting the desiel only models then why is mine doing the same thing. Parts cant be ordered either. Please look into this matter.

- Madison, GA, USA

This is an amendment to campaign 11684444 as there is some inaccurate info as it pertains to the diagnostic- 2021 Chevrolet Tahoe, Driving 25 MPH, in the neighborhood, my Tahoe kicked into neutral and abruptly stopped in the middle of the street. I immediately tried to restart it, however it would not start. After about 15 minutes, we tried again and it started enough to make it back to my in laws house, where it remains parked today. We did a diagnostic test and received the code for Fuel Pump Control Module failure. Contacted the Chevrolet dealership I bought my vehicle from and they indicated this is a common issue and the part is on back order. This is a very dangerous risk to safety and should be covered under a recall. I've seen where GMC issued a recall for the exact same issue, but only for Tahoes with 6.2L V8 engine; Mine is 5.3L. I am confused why that matters as it poses the same safety risk across the board. Very dangerous. Please consider this as a recall.

- Pelham , AL, USA

Rapid deceleration at 55mph on highway, followed by console message "reduced acceleration" with check engine light. Fortunately rolled into dealer within a mile. After analysis, they stated the transmission valve body and electronic control component needs replacement over $3,000. after tax. No warning signs prior. NTSB recall N24254441 covers only diesel engines not gas with same problem in 10 speed transmission.

- Hamburg, NY, USA

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 NHTSA 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

- Chattanooga, TN, USA

The affected systems are the power train, engine, and electrical. My 2021 Chevrolet Tahoe experienced failures consistent with GM Technical Service Bulletin 21-NA-149 (engine wiring harness chafing) and the conditions outlined in Recall N232404190 (valve body failure, November 2024). Beginning in March 2025, the vehicle displayed warning lights and messages including Check Engine, Traction Control, Service Transmission, and limp mode (Reduced Acceleration -?" Drive with Care). The vehicle shifted erratically, lost power, and occasionally failed to accelerate, creating a serious safety hazard at highway speeds. These problems were documented at AutoNation Chevrolet South Clearwater, where multiple diagnostic trouble codes (P0700, P0717, P2714, P2716, P0706, and U-codes) were recorded but not properly investigated. No test drive was performed despite being claimed by the service technician, and the applicable TSB was not referenced. By July 2025, the condition worsened into a complete transmission failure, with additional codes (P0700, P077C, P17F6, P17FB, P1872). The dealer-??s estimate required a full transmission replacement at nearly $10,000. GM reviewed the case through its internal Policy Evaluation Tool and increased goodwill assistance from 15% to 40%, while AutoNation contributed only $500. GM-??s partial contribution confirms the defect is recognized, yet this VIN remains excluded from the official recall. This issue placed my family and other motorists at significant risk, as sudden loss of power and shifting failures occurred during normal driving conditions. Dealer records, GM documentation, and photographs of warning messages are available. I request that NHTSA expand Recall N232404190 to include affected VINs such as mine, since the symptoms, diagnostic codes, and confirmed failures match exactly what GM has already identified as a known safety issue.

- Odessa, FL, USA

The affected components are the electrical system, engine, and power train. In March 2025, my 2021 Chevrolet Tahoe displayed multiple warning lamps across the dash, including traction control and check engine lights. The vehicle shifted erratically and sometimes entered limp mode. I brought the vehicle to AutoNation Chevrolet South Clearwater for inspection. The dealer replaced the battery, dismissed my concerns, and stated that a test drive was performed, but the mileage in and out on the invoice was identical, showing it never actually occurred. Diagnostic trouble codes (P0700, P0717, P2714, P2716, P0706, and multiple U-codes) were present but were not fully investigated. A GM Technical Service Bulletin (21-NA-149, December 2022) covers these exact symptoms (caused by engine wiring harness chafing), but it was never referenced or applied. Because the problem was not addressed, the condition worsened. By July 2025, the vehicle suffered a complete transmission failure. At that point, the dealer confirmed the issue, documenting transmission slipping, shuddering, noise, and additional codes (P0700, P077C, P17F6, P17FB, P1872). GM increased its goodwill contribution from 15% to 40% of the $9,925 repair cost, while AutoNation offered only $500 despite their role in the missed diagnosis. Safety Risk: My family and I were at risk each time the vehicle stalled, lost power, or shifted erratically while driving, including at highway speeds. These failures created a significant risk of collision. The drivability problem was not properly confirmed in March 2025 despite multiple codes being present. By July 2025, the dealer acknowledged and confirmed the transmission failure. The vehicle remains available for inspection, and I have retained all invoices, diagnostic reports, and communications with GM and the dealership.

- Odessa, FL, USA

I am submitting this complaint regarding my 2021 Chevrolet Tahoe (VIN: [XXX] ) which has developed a severe transmission shudder at both low and highway speeds. The issue has been confirmed by my Chevrolet dealer, who provided an estimate of $5,492.18 for torque converter and valve body replacement. This failure is identical to the torque converter shudder problem documented in GM service bulletins and special coverage adjustments for other GM vehicles of the same make, model, and model year. However, my VIN is not currently included in those programs, leaving me without coverage despite experiencing the exact same defect. I believe this condition poses a serious safety risk, as the shudder occurs while driving at highway speeds, causing vibration, hesitation, and potential loss of control. These symptoms could lead to accidents if the vehicle fails to respond properly during acceleration or lane changes. Given that this appears to be a widespread defect affecting multiple GM vehicles, I respectfully request that NHTSA investigate and consider expanding any related recall or special coverage programs to include affected VINs such as mine. Please let me know if further documentation, service records, or dealer estimates are needed to support my complaint. Thank you for your time and for working to ensure vehicle safety. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Tomball, TX, USA

In May 2025, my 2021 Chevy Tahoe experienced transmission failure related to the valve body. The vehicle has now been at the dealership (Richard Chevrolet in Cheshire, CT) for over 2 months with no timeline for repair due to a national backorder on the part. This issue is widely reported among 2021 Tahoes and other GM vehicles, and appears to be a systemic transmission defect. I was never notified of any recall or service bulletin, and I-??m still making monthly payments on a vehicle that is inoperable. The rental provided does not suit my family-??s needs, and GM has been unable to offer a resolution or clear update. This type of critical drivability failure should be classified as a safety concern, especially considering the volume of similar complaints and the absence of repair parts. I am requesting NHTSA investigate this issue further and take action if warranted.

- Prospect, CT, USA

On 01/03/24, the vehicle stalled and smoked on the Suncoast Parkway. All dashboard warning lights and messages illuminated, and the vehicle entered emergency park mode. OnStar was contacted and the vehicle was towed to Jenkins Chevrolet in Homosassa, FL. The failure was linked to a broken pulley and belt system that damaged the ECM and wiring harness. No DTCs were pulled, and mileage in/out was 80042/80043-?"no test drive performed. On 08/06/24, the vehicle returned to Jenkins for a roaring noise. A pulley bearing was replaced, possibly related to the earlier failure. Again, no drivability evaluation or codes recorded. On 03/09/25, the same full system warning lights/messages appeared again. The vehicle experienced harsh shifting and delayed acceleration. It was taken to AutoNation Chevrolet South Clearwater on 03/10/25. DTCs (P0700, P0717, P2714, P2716, P0706, and U-codes) were found but dismissed. Only the battery was replaced. Mileage in/out was 99494-?"no test drive performed despite claims one occurred. On 07/08/25, the vehicle again showed full dashboard warnings. Brought back to AutoNation on 07/09/25. On 07/14/25, customer received a $9,177.85 estimate including full transmission replacement. Safety was at risk due to repeated stalling, loss of acceleration, and emergency parking mode while driving or merging. These failures could have led to accidents or left the vehicle disabled in traffic. Driver and children were present during each incident. The vehicle is enrolled in OnStar and the MyChevy app, which provide monthly health reports. Despite these incidents, no faults or warnings were ever shown in the reports. Vehicle remains available for inspection. A case is open with GM. Across 4 service visits, GM-certified dealerships failed to follow proper protocols, including code checks, drivability assessments, and test drives-?"contributing to delayed diagnosis of transmission failure.

- Odessa, FL, USA

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving at an undisclosed speed, the transmission unexpectedly downshifted to a lower gear. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed that the transmission valve body had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 39,000.

- Park Ridge, IL, USA

The contact owns a 2021 Chevrolet Tahoe. The contact stated that the vehicle displayed "Reduced Power, " and the rear wheels started to lock-up. The contact was able to keep control of the vehicle and continued driving. The vehicle was taken to the dealer, who completed the repair under NHTSA Campaign Number: 24V797000 (Power Train). The contact stated that after the recall repair, while leaving the dealer and driving approximately 10 MPH, the vehicle veered off to the right and ended up partially in the next lane. The contact stated that the vehicle unintendedly shifted into neutral, and the message to "Press Start Again" was displayed. The contact was able to restart the vehicle and parked the vehicle in a nearby parking lot. The contact restarted the vehicle and drove back to the dealer. The failure recurred twice while returning to the dealer. The dealer diagnosed that there was a fuel pump drive failure. The vehicle was not repaired. The manufacturer was informed of the failure and confirmed the VIN was no longer under NHTSA Campaign Number: 24V797000 (Power Train). The manufacturer opened a case. The failure mileage was approximately 69,000.

- Raeford, NC, USA

Recall issued by GM (N25249000/NHTSA 25V274) on powertrain/crankshaft and took car to GM dealer and was refused service or safety inspection. Told that they were told by GM not to inspect or service vehicle at this time. How can a safety recall be issued but GM not be ready to inspect or remedy issue?

- Phoenixville, PA, USA

Check Engine Light Came On. Upon Diagnosis', the engine is misfiring, lifters are not performing correctly and there are critical engine alerts and an estimate of 11,000 to fix. 2021 - 83,000 miles v8 - 5.3 NOT the 6.2 and no one will help me bc my power train expires. I am the only owner. Second brand new Tahoe ai bought from this dealership and they are doing nothing to help.

- Frisco, TX, USA

While traveling on the highway one day, my 2021 Chevrolet Tahoe began warning lights on the dashboard. Shortly after, it running roughly, , and jerking, so I pulled over to investigate. There no visible smoke, so I drove to the nearest auto parts store, where they ran a diagnostic test that returned a code of P0306. I then took vehicle back to the dealership where have always received oil changes and repairs. I have never visited any other dealership, relying on certified GM/Chevrolet dealerships. After inspecting the vehicle, they informed me that the lifters needed replacement advised that it would be best to replace the engine entirely. Upon further research, I discovered that issue has been affecting many people in our area and across the United States. This needs to be addressed, as the vehicle is only three years old, purchased brand new with zero miles, and I have not done anything out of the ordinary to cause this problem. The vehicle being 70,000 and 12.000 for repairs is insane.

- Leesburg, GA, USA