2021 GMC Sierra 1500: engine knocking or ticking

Filed Oct 30, 2026 · Engine, Steering · 34,000 miles · AK

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving 45 MPH, there was an abnormal knocking sound coming from the vehicle. The vehicle started hesitating, and there was a loss of power that became worse over time. Additionally, the “Service Engine” and “Power Train” warning lights were illuminated. The messages “Loss of Steering Assist - Be Alert” and “Service Parking Brake” were displayed. The following day, the vehicle was driven in LIMP Mode to the dealer and was diagnosed with engine failure. The contact stated that there was an ongoing the federal safety agency investigation associated with the 6.2L engines. The failure mileage was approximately 34,000.

Filed Oct 17, 2026 · Engine · MO

Loud engine knock, made it to dealer. Dealer confirmed engine failure as defined in the applicable recall. No idea when a replacement can be aquired. Unable to drive anywhere due to design and manufacturinf issues I did not cause.

Filed Oct 12, 2026 · Engine · OH

While towing a trailer on 6/26/26, the 6.2L L87 engine suffered a sudden drop in oil pressure, began knocking, and completely lost motive power on the roadway. Because the engine seized instantly, the vehicle experienced a sudden loss of power steering and power braking while managing the extreme weight of a trailer. This combination created a severe and immediate safety hazard, forcing me to maneuver a heavy, unpowered truck and trailer combination through active traffic to the shoulder without full steering or brake control, putting my life, my passengers' lives, and the safety of surrounding motorists at extreme risk. My dad read the codes before we took it to my mechanics and the only code I can remember is P0016. I took it and dropped it off at my local mechanics on 6/28/26. This is what my mechanic said: No Start-Truck came in not running. Had timing codes. I believe the crank bearing failed causing the engine to lose oil pressure. With the sudden loss of oil pressure, the timing chain tensioner slacked and caused the cam/crank to go out of time. Drained engine oil and found bearing material. We also cut oil filter open and found more bearing material. The timing cover was removed and verified the cam timing was off. In conclusion the engine has failed and will need full replacement. This is the exact failure mechanism under active the federal safety agency Investigation EA26005.

Filed Oct 7, 2026 · Engine · TX

Truck was in motion and the engine light started blinking then stopped. A couple miles down the road the truck jilted and the engine light came on again. The Service ESC and emergency parking brake light came on. The truck started shaking. We pulled over and parked. Turn off the truck and when we turned it back on it started shaking. When we drove we started hearing popping, knocking, loss in power of the vehicle. This could’ve caused serious damage to ourselves or other drivers if we could’ve have stopped. Vehicle is being inspected. Multiple same vehicles have had the same issues in my town. At least 5 that we know of. At one point all of the lights came on and now there is just a few lights. More than what I listed earlier.

Filed Sep 9, 2026 · Brakes, Engine · MI

XXX 2021 GMC Seria 108,339 miles driving home from [XXX] in town and out of nowhere the lights on the dash light up I saw it say adaptive steering and something breaking. There was a lot going on as the steering was rapidly shaking limited breaking while trying to avoid a collision. The engine started a loud knocking sound and sudden smoking out tail pipes. I was able to get the truck stopped turned it off and sat there for a while trying to collect myself. Restarted the truck and slowly drove it to my home 2 miles away. It was flatbed to local GM dealer that quickly diagnosed it saying heavy smoke knocking needs New Engine! They won't confirm exactly what the internal engine failure is. Other than its Failed. The engine build date is 2020 day 350 My VIN is not currently in the current GM engine recall However it's certain this failure is totally related to GM's engineering design and Manufacturing issues. Look deeper into the recall date ranges this failure is clearly a victim. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 9, 2026 · Engine · AZ

Catastrophic Engine Failure due to Lifter Failure at approximately 51,000 miles driven. This has been confirmed by the dealership and reported/escalated to General Motors. The truck is at the dealership for repairs. General Motors offered to cover 65% of the repair as a Goodwill sign. As the 60K powertrain warranty had expired. This truck has the same components that are covered under the recall for the same model year. However the recall only extends to March 1, 2021 Manufacture date. My truck was manufactured a few weeks prior to that so it was not included. GM refused even discuss this could be potentially due to a recalled issue. Multiple warning lights and error messaged were present on the dash indicating issues when it failed. Additionally, a loud metallic knocking noise was present at speed and idle. Power was significantly reduced and the engine was running very rough.

Filed Aug 28, 2026 · Engine · AL

2021 GMC Sierra 1500 equipped with 6.2L L87 engine. At approximately 97,000 miles, the engine developed a significant knocking noise. I immediately took the vehicle to an authorized GMC dealership for diagnosis. The dealer determined that the engine required replacement but advised that my VIN was not included in GM Recall 25V‑274. The dealer quoted approximately $15,000 for replacement. I subsequently had an independent repair facility replace the failed engine with a genuine GM replacement engine at a cost of approximately $12,400. I am reporting this because the failure appears similar to the L87 engine bearing/crankshaft failures addressed by Recall 25V‑274, despite my VIN not being included in that recall.

Filed Aug 28, 2026 · Engine · 81,000 miles · OK

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving at 60 MPH, the vehicle began to shake uncontrollably. A knocking sound was heard from the engine, and the vehicle entered limp mode. No warning lights illuminated. The contact was able to coast the vehicle to the residence. The vehicle was later towed to the dealer, where it was diagnosed that the engine failed and needed to be replaced. The contact associated the failure with the federal safety agency Campaign Number: 25V274000 (Engine and Engine Cooling). The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall, and the contact was advised to file a complaint with the federal safety agency Hotline. The failure mileage was 81,000.

Filed Aug 28, 2026 · Engine · MN

Driving on the highway lost proportion/acceleration, loud knocking coming from the engine

Filed Aug 25, 2026 · Engine · LA

While driving down an isolated 2 lane road in West Texas, the engine in my 2021 GMC Sierra 1500 began making knocking sounds and vibrating badly. The truck's acceleration was extremely sluggish and the vibration worsened at slow speeds. I was able to slowly make my way back towards a dealership, where the diagnostic teardown revealed a bent pushrod and camshaft damage.

Filed Jul 18, 2026 · Engine · OK

I'm not sure if they've pulled it out yet. They said two weeks to get motor. Engine started shaking and then started knocking. Had wrecker take it to GMC dealer they said it needs an engine. It is a 2021 6.2 carbon pro 1500 Sierra AT4 it did not come up on recall list and I don't know why? it obviously the same problem.

Filed Jun 23, 2026 · Engine · NE

The AFM caused piston flapping and other major engine problems such as abnormal wear. The problem with the engine could have caused a catastrophic failure along the side of a highway. The problem has been diagnosed and the engine has been replaced at my expense. The repairs were made at a local mechanic shop. The engine would start make a loud ticking noise at 2000 RPM or above. The mechanic shop referred to this as piston flapping. This was caused by inadequate oil pressure at all cylinders due to the Active Fuel Management.