general problems of the 2021 Chevrolet Tahoe - part 1

Suspension system failed- had to replaced, car difficult to control when operating. Repaired by dealer- country Chevrolet, benton ky- owner paid for repair. [xxx] engine failure- knocking and difficult to drive on returning trip from louisville ky to benton, ky. Taken to dealer on 4. 6. 2026 - made it without being towed- extremely slow- traffic hazard- Tahoe has lots of road miles- always repaired and serviced by dealer. There were no warning lights, symbols or indicators that there was a problem. Dealer still determining the extent of the damage. [xxx] benton ky information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

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.

During highway driving, alert on dashboard stated “electrical system failing enter idle mode”. Tahoe slowed down and then engine began knocking right as it shut off resulting in needing to coast to the shoulder of the highway safely since engine was off. Towed to dealership and then they came back saying needed a new battery, new alternator belt, pulley and water compartment. After those installed, additional call was made indicating the engine needed a full replacement as it keeps overheating despite no sensor alerts and codes are being tripped. Here we are asked to pay 16k for new engine install and unable to fix.

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 NHTSA 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 NHTSA hotline to report the failure. The failure mileage was approximately 100,000.

Motor is not included in the 6. 2 recall for some reason. It is consistently burning through 3 qts of oil every 2-3k miles. This is a major concern considering I travel a lot. I want to know why this specific motor isn’t covered in the recall considering it is having the same issues as the current recall. This has been an ongoing issue and I have been waiting for a recall notice. Gm dealership says there is no recall and won’t ever be one.

Since March of 2025 I have identified a critical safety defect with my vehicle. When driving and without warning, the vehicle unexpectedly shifts to neutral, experiences a loss of propulsion, and the engine shuts off. This has occurred multiple times in which I narrowly escaped collisions with other vehicles or objects. If this would occur at a high rate of speed, it would certainly result in serious accident including possible fatality. I have experienced three near-accident scenarios when I had children in the vehicle. I have worked with classic Chevrolet in sugar land, texas who has made six attempts at repair. They have each time found a different component attribute to an error code and replaced that part. After each visit they tell me that the car is fixed and safe to drive. They have never been able to provide a clear explanation as to why I am experience this reoccurring issue, but attribute it to a different part each time. Within 5 days to 2 months, the incident repeats. I have recent video of the incident that I can share. Chevrolet customer care has been minimized my concern and informs me that their service staff has found the vehicle to be fully operational and safe to operate. I have spent over $6,000 in failed repairs. I do not feel safe operating this vehicle. That list of repairs includes: March 7, 2025 - battery replacement March 28, 2025 - DC/DC power converter April 22, 2025 - ecm updates January 8, 2026 - •throttle body replacement •serpentine belt replacement •engine air filter replacement •transmission fluid flush •coolant fluid flush •fuel injection cleaning •hydrogen carbon cleaning service January 23, 2026 - power control module (recall) January 30, 2026 - rear differential system replacement March 10, 2026 - • replacement of the high-pressure fuel pump • replacement of the DC power supply converter • hydrogen carbon cleaning service I can share all invoices. Chevy is not taking this matter seriously. Please support.

On March 14,2026 I was driving 80 mph on the interstate and the vehicle shifted to neutral and shutoff. Shortly before that the vehicle revved to 4000 rpm and you could feel rhythmic vibrations. The vehicle was towed to a chevy dealership and diagnosed as loss of propulsion needing a new engine. Tahoe had 104,000 miles at failure.

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving at various speeds, the forward collision avoidance message was intermittently displayed. The vehicle was taken to a dealer, where a computer module was replaced. While driving at various speeds, there was an intermittent knocking sound coming from the engine, with the check engine warning light illuminated. While driving at an undisclosed speed, the knocking sound became constant. The vehicle was driven to the dealer, and upon inspection, the mechanic discovered a bent engine rod inside the engine. The vehicle was diagnosed with engine failure, and the contact was provided an estimate for the repair. Upon investigation, the contact discovered the failure was associated with NHTSA campaign number: 25v274000 (engine and engine cooling). The manufacturer was initially notified of the failure through the dealer, and the contact was later informed that the manufacturer agreed to cover half the cost of an engine replacement. Upon calling the manufacturer directly, the contact was referred to the NHTSA hotline to report the failure. The vehicle was not repaired and remained with the dealer. The failure mileage was approximately 72,000.

My 2021 Chevrolet Tahoe engine seized while I was driving on the highway. All I heard was a loud clunk then there was a sudden power loss while I was driving before I could even get to the side of the road. I had to pay, out of pocket, to get a tow because the vehicle failed to crank or start. I had the vehicle towed to the chevy dealership in paramus, NJ just to find that this is a known recalled issued with the 5. 3l, v8 engines which is the engine my vehicle has. There seem to be problems specifically regarding defective connecting rods or the crankshaft but for some strange reason my vehicle's VIN number is not included in this recall although it is the same year, same vehicle, same engine and same problem. My vehicle should be included in the recall so it can be repaired for free at the chevy dealership in paramus, NJ as I use this vehicle to transport children and that is very unsafe to have this defect and not fix it for free when it is not the fault of the driver.

While driving home late at night, the vehicle experienced a sudden mechanical failure in the engine. I was traveling approximately 2 miles per hour while slowing to stop at a stop sign when there was a loud “clunk,” followed by an abrupt stop of the vehicle. Immediately after this occurred, multiple dashboard warning lights illuminated, and a knocking sound began coming from the engine. The vehicle is currently not operating normally and is available for inspection upon request. This incident occurred late at night while I was driving with my two young children in the vehicle. The sudden and unexpected stop put us at risk of being rear-ended or stranded in an unsafe location. The loss of normal vehicle operation created a dangerous situation, especially given the time of night, location, and the presence of my children. There were no warning lights, messages, or noticeable symptoms prior to the incident. All warning lights illuminated only after the loud clunk and abrupt stop occurred. The knocking sound from the engine began immediately following the failure. I now am in a rental car that costs $700 a week that my insurance doesn’t cover.

I was driving down I-5 at 75mph and the truck shut off while driving. Couldn’t get to start. Paid over $1k for a new battery cause dealership couldn’t replicate problem. Next day doing 75mph on freeway engine through a rod.

My truck was driving perfect and I went to pull into a parking lot in arkansas where I live in long story short it started acting funny trying to idle out and then I heard a knocking noise. It happened twice. Then my service esv light come on next my motor light come on then my auto for a collision system failure light come on. It’s on the dash anyway my vehicle is not running around. It has hardly no power and I smell something under the hood from time to time burning it’s kinda like an electrical smell. I’m not sure. I’m not a mechanic. I’m a [xxx]. I’m a [xxx]!!! but I have to have a way back back-and-forth to work and I cannot drive this vehicle. I have been driving it to work and just straight to home and that’s only like a mile from the shop but I need a replacement vehicle I need to sell mine at wholesale value as you guys said you would that would be greatly appreciated. God bless you guys. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving and attempting to slow down to approximately 35 mph, there was an abnormal clunking sound coming from the vehicle. The contact believed that the sound was caused by ice buildup on the mud flap, but shortly afterwards, the engine revved unexpectedly, with the check engine warning light illuminated, and the message “reduce acceleration - drive with care” was displayed. The vehicle started to coast unintendedly. The contact stated the vehicle returned to normal operation after a short while. The vehicle was taken to a local dealer to be diagnosed. The mechanics pushed the vehicle out of the parking spot before inspecting the vehicle. The vehicle was diagnosed with transmission valve body failure. The contact was informed that the transmission valve body needed to be replaced. The vehicle was not repaired. The manufacturer was contacted and referred the contact to the NHTSA hotline to report the failure. The approximate failure mileage was 88,342.

1st issue: 9/2025, after driving from another city to my home at 55-75 mph. As I pulled up home, the car just stalled and wouldn't start. I googled issue to find out it was a commonly known issue by gm. If fuel pump control module had happened while driving faster and not on my street to roll up to curb. I would have or could have been deadly. I find out what part # and local dealer knew there was a recall but told me he never heard about it and charged me for part. I installed in front of home on street and have been trying to get money back after reporting to gm I repaired my fuel pump control module and have been trying to get my money back from a repair done on 9/29/2025 by me. Gm says it's looking into still after I keep calling them on status of this notice. I still have old part. I have filled out all reimbursement forms. 1st the danger of it failing and now no money. By the time engine light comes on you have no power for any stopping or steering. #2 engine 2021 Tahoe high country 6. 2 l no recall has been sent. Gm has known about an engine that has multiple failure issues that could get you in a serious accident/death by just stop running, while just driving at any moment, internal failures and main seal leaks, more! mine just poured oil out on driveway after driving 6 miles to church and back. This will be the largest and most deadly auto issue in history. They even had dealers now with any on lot with this engine a stop sale order. Aprox. 800,000 of these engines are out there, local gm dealer says there is no recall. 2021 to 2026 and they have only changed out aprox. 2800 engines and telling me mine sitting in driveway is not on recall. Bs. These engines are in their high-end trucks, SUV's, escalades. Someone needs to get gm to do what's right and replace with new engines. That have been tested, all issues before someone has to die. Trying to keep silent on internet is sad. Yes its going to cost billions. But to keep customers safe and not scared.

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.

2021 chevy Tahoe rst. Bad lifter valve, warranty not wanting to cover replacement for new one.

* sudden catastrophic engine failure. * the car lost power in the middle of a high traffic, very dark country road, forcing her to stay in the middle of the (undivided) road in the dark hoping cars didn't slam into her. A collin county sheriff was dispatched to keep her safe until the tow truck arrived almost two hours later. " * the vehicle was towed to a dealer where they confirmed that the torque converter, valves, lifters had failed. Dealer didn't disclose that there was any issues for these engines, which there is. It's a 6. 2l v8 Tahoe high country. * it has only been inspected by the dealer, not the manufacturer, police, insurance representatives, etc. . . * the vehicle indicated a traction control problem, then the engine light came on, and then the engine failed followed by loss of power. All happened in rapid succession with no opportunity for the driver to get to a safe location. * there was no warning or other symptoms preceding this. The vehicle has always been faithfully serviced at chevy dealerships consistent with the manufacturers recommendations.

Lost power. Engine went into a limp mode. Engine starting knocking loudly and service esc came up on dash along with check engine light. Took it to the dealer and they said a lifter spun and damaged the camshaft. Dealer says it’s not covered by recall. Vehicle has been in chevy dealer garage for 2 weeks and no repair yet.

While driving normally, the vehicle developed engine performance issues and was diagnosed with a catastrophic camshaft failure at approximately 85,000 miles. The vehicle has received regular oil changes with full documentation and has not been abused or neglected. A licensed mechanic confirmed that the camshaft was severely worn and damaged, consistent with afm/dfm lifter failure, which is a known issue on gm v8 engines. This failure caused significant internal engine damage requiring major repair. The failed camshaft has been retained as physical evidence. A camshaft should not fail prematurely under proper maintenance. This appears to be a manufacturing or design defect, not normal wear and tear, and presents a potential safety concern due to sudden loss of engine power.

While driving on I-90 in montana on a clear, sunny day at the posted speed limit of 80 miles per hour for one hour, the vehicle began making knocking noises then, all of a sudden lost power. Upon inspection at the nearest gm dealership service department in butte, mt, I was told something within the engine broke. I have attached an emailed repair bid from the gm service department and have copied and pasted the highlights here: -engine, lines, radiator, water pump, and tune up ($14,400. 00) -cam, lifters, lines, radiator, water pump, and tune up ($11,400. 00) -master cylinder/ebcm ($3,310. 00) previous to the incident, all recommended and routine maintenance was performed at intervals recommended by gm and by gm dealership service departments and/or the valvoline oil change location in missoula, montana. The odometer reading was between 95,000 and 96,000 miles at the time of incident.

Afm lifter collapse on cylinder 6 written repair estimate or a diagnostic report showing p0306 + lifter failure.

I was driving on the highway at approximately 35mph when I noticed there was no response from the accelerator. I shifted the vehicle into neutral and coasted onto a side road and call onstar for assistance. The dashboard indicator said to restart engine. I attempted to restart, but the engine would crank but not turn over (start). The vehicle was towed to the dealership where the fuel pump assembly was found to have failed and need replacement.

Having to replace the radiator due to it leaking around a plastic connection to metal. Was told by the dealership this has an updated part from gm due to it being a known issue.

The vehicle stalled while driving down the road and started making a loud ticking noise, the engine light went on. It was brough to the dealership where they did an engine rebuild. They replaced 16 lifters and camshaft, a pulley belt and gaskets. The vehicle was picked up, however, a month later the oil low add oil light came on and the oil tank was more than 2. 5 quarts low indicating extreme burning of oil. The vehicle is shuttering on acceleration of low rpms. Brought it back to the dealership and awaiting further instruction. It caused a major safety concern because it has the potential to stall due to a motor defect on a major highway, putting my family and possibly others at risk of harm or death.

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.

1. What component or system failed or malfunctioned, and is it available for inspection upon request? answer: the vehicle’s 6. 2l l87 v8 engine suffered a sudden internal mechanical failure involving the connecting rod, rod bearings, and crankshaft assembly, resulting in catastrophic engine damage. The failure mode is consistent with the defect described in gm recall n252494001. The engine and all damaged components are fully available for inspection upon request. 2. How was your safety or the safety of others put at risk? answer: the engine failed without warning while the vehicle was in motion, causing an immediate loss of propulsion. This created a hazardous situation where the vehicle could no longer accelerate or maintain speed in traffic, increasing the risk of a rear-end collision or loss of vehicle control. Gm’s own recall documentation identifies this exact failure mode as a significant crash risk, and that same hazard occurred in my case. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? answer: yes. A service technician confirmed catastrophic internal engine failure consistent with connecting-rod or crankshaft damage. The dealer also verified that the engine is inoperable and requires full replacement. 4. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? answer: no, the engine failed while in motion and was taken to the closest mechanic. Inspections by an insurance representative or manufacturer representative can be arranged. The vehicle and damaged engine remain available for further examination. 5. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? answer: no. There were no warning lamps, diagnostic messages, or drivability symptoms prior to the catastrophic engine failure. The failure occurred suddenly and without any advance indication. All service records are available.

I am submitting this complaint to the national highway traffic safety administration (NHTSA) regarding a sudden engine failure in my 2021 Chevrolet Tahoe equipped with a 6. 2l v8 engine, which posed a serious safety risk. I was driving on the highway at approximately 65 mph with cruise control engaged. Suddenly, the vehicle lost all power, disengaging the cruise control, and the check engine light began flashing rapidly. I managed to exit the highway safely. While stopped at a traffic light, preparing to turn into a nearby repair shop, the car started shaking violently from side to side, making it difficult to control. I took the vehicle to a firestone shop and a local Chevrolet dealer, both of which diagnosed massive engine failure and indicated that the engine will most likely need to be replaced. The symptoms I experienced—sudden loss of power at highway speeds, flashing check engine light, and violent shaking—are in line with issues reported in other gm 6. 2l engines that have been recalled. ? for whatever reason, my 2021 Tahoe, which falls in the middle of the affected model years for these recalls (e. G. , gm recall n252494001 for 2021-2024 vehicles with 6. 2l v8 engines due to defects in connecting rods and crankshafts leading to engine damage and loss of propulsion), is not included under the broader gm 6. 2l engine recall, ? although I experienced very similar issues. The biggest safety concern was the engine essentially losing power at highway speeds, which could have led to a crash. I urge NHTSA to investigate and expand coverage if necessary to ensure public safety.

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 NHTSA hotline to report the failure. The failure mileage was approximately 87,893.

The contact owns a 2021 Chevrolet Tahoe. The contact stated that while driving 20 mph into the driveway, the engine seized. The contact stated that the service traction, service esc, and engine warning lights were illuminated. Upon research, the contact associated the failure with NHTSA action number: ea25007 (engine, engine and engine cooling). The vehicle was towed to the local dealer, where it was diagnosed, and dtc: p0300, p050d, and p0302 were retrieved. The vehicle was not repaired. The manufacturer was notified of the issue and offered to help with the cost of the repair. The approximate failure mileage was 64,572.

My Tahoe is throwing a low engine oil code and burns through about 2 quarts of oil in between oil changes. Other Tahoes of the same year make and model have been recalled for the same issue but mine was not.

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

#1 ) el motor presento esta fallas en las 98mil millas, el motor empezó con un alto consumo DE aceite DE 5 cuartos DE aceite cada 3 mil millas, en repetidas ocasiones estábamos DE viaje junto a mi familia, mi esposa, [xxx]. Un dia hicimos una para frente a un semáforo, y en seguida el vehículo empezo a tirar una gran cantidad DE humo blanco por la salida DE los escapes, mis hijas entraron en pánico una DE ellas intento salir del vehículo en plena calle principal, ella sintió miedo y pensó que el vehículo se estaba incendiando. En ese momento le dije que ES un problema DE el vehículo pero que no era incendio. El humo que sale repentinamente ES derivado DE el excesivo consumo DE DE aceite en el motor. A mi punto DE vista esto representa un alto riesgo en la carretera. Poniendo riesgo la vida DE mi familia, la mía misma y la terceros en la carretera. El aceite que consume significa que esta llegando a las cámaras DE combustión en el motor y esto puede deribar, que en un momento determinado el aceite sirva como combustible y el vehículo en marcha se acelere sin control y provocar graves danos a la integridad DE mi familia y asta la muerte DE terceras personasla carretera. #2) la transmisión en este vehículo tironea bruscamente cuando hace un cambio DE velocidad esto representa un alto riesgo para mi familia, este vehículo representa un alto riesgo DE que cuando haga un cambio DE marcha rompa algunos componentes internos y esto lleve a una parada repentina y provocar un accidente mortal. #3) últimamente este vehículo a presentado inestabilidad en el volante, a la fecha DE esta nota el problema tiene al rededor 5 días . El vehículo se llevo al consecionario maik Chevrolet ubicado en 11711 katy fresa y, houston TX 77079, ellos hicieron las respectivas pruebas en el vehículo y determinaron que el vehículo no era apto para estar en la carrtera debido a las fallas que presenta en la transmisión y el motor. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

2021 Tahoe with l87 engine lifters failed at 2000 miles ,was fixed by dealer then at 82,000 miles same failure only now engine failed, I was driving home when it failed almost got in an accident lost power engine codes were blinking , took to dealer been there since October 20th still at dealership.

We have experienced a loss in power that is accompanied with an audible engine knocking sound. The loss of power affected our ability to safely merge into the highway.

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.