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Owner complaints · Engine

2021 GMC Sierra engine problems

355 of the 575 complaints owners filed with NHTSA about the 2021 GMC Sierra name the engine (NHTSA’s “Engine” heading — the engine and its cooling system). Filed under the same heading: 440 manufacturer bulletins, 1 recall, 4 NHTSA investigations. Every figure below is a document in a federal file, linked; none is a failure rate, and none is a verdict on any one car.

355 complaints 62% of this model year’s 5 a fire typically at 59k miles

What owners filed about the engine

Source: NHTSA complaint database

355complaints name the engine

0 of the 355 reports a crash · 5 a fire · 1 injury. Self-reported, unverified.

Filed per year: 2020: 1 · 2021: 19 · 2022: 13 · 2023: 9 · 2024: 14 · 2025: 183 · 2026: 116

59kmiles, typically

Half of the 71 owners who gave an odometer reading reported the engine problem between 35,000 and 83,000 miles. A median of reports, not the life of a part.

62%of this model year’s complaints

575 complaints in all about the 2021 GMC Sierra, 116 filed in 2026. The whole picture, every system →

Counts are owner reports to NHTSA, not verified defects, and scale with how many of these were sold; nothing here is a rate. NHTSA groups complaints coarsely, so “Engine” means the same area of the vehicle, not one fault.

Across model years: GMC Sierra engine problems, every year on file →

In owners’ own words

Source: NHTSA complaint database

Filed with NHTSA by the people who own these cars, about the engine. Quoted as written, with anything identifying removed; unverified reports — what was said, not a finding that it was true.

While driving on the highway my truck started to buck and had a loud engine knocking noise. Speed was greatly reduced so much so that I was going under 45 mph in a posted 65. The check engine light did not come on. While sitting on the side of the highway there was a severe engine knock only when the revs on the engine were increased.

Engine Sep 9, 2021 NHTSA owner report

The truck has 7500 miles on it and the check engine light keeps coming on then goes back off. It is impossible to schedule service as the light goes off before it gets to dealer. The when driving the truck many times the check engine light will flash for a minute or so and then remain on steady.

Engine Sep 1, 2021 NHTSA owner report

Bought GMC Sierra 1500 brand new. At approximately 2300 miles the engine light started blinking. I took it in and they said they couldn't find anything wrong with it. At 3700 miles it started again and I took it in. It has a bent push rod causing engine failure

Engine Aug 23, 2021 NHTSA owner report

GM has a lifter problem that causes complete engine failure. When this happens the engine completely locks up rendering the vehicle completely shutdown. This is happening over and over in early stages of 2021 Chevrolet and GMC Vortec V-8s.

Engine Jul 29, 2021 NHTSA owner report

The contact owns a 2021 GMC Sierra 1500. The contact stated that while driving in inclement weather, the vehicle stalled without warning. The contact looked under the vehicle and saw that engine oil was leaking from a puncture in the oil pan.

Engine at 5,800 miles Jul 28, 2021 NHTSA owner report

What is on file about the engine

Source: NHTSA recalls, investigations and manufacturer communications

Recall filed under this heading

25V274000 High
Apr 24, 2025 · 597,571 vehicles
General Motors LLC (GM) is recalling certain 2021-2024 Cadillac Escalade and Escalade ESV, Chevrolet Silverado 1500, Suburban, and Tahoe, GMC Sierra 1500, Yukon, and Yukon XL vehicles equipped with a 6.2L V8 gas engine. The connecting rod and/or crankshaft engine components may have manufacturing defects that can lead to engine damage and engine failure.

NHTSA investigations

EA26005 Loss of motive power due to engine failure post recall remedy
opened Aug 20, 2026 · open
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 R…
RQ26001 Loss of motive power due to engine failure post recall remedy
opened Jan 16, 2026 · closed Aug 20, 2026
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 R…
EA25007 Loss of motive power due to engine failure
opened Oct 23, 2025 · open
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/Y…
PE25001 Loss of motive power due to engine failure
opened Jan 16, 2025 · closed Oct 23, 2025
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 so…

440 manufacturer bulletins filed under this heading

The 0 newest are listed; every one is on the model year’s page. Quote the document number at a service desk — it is a diagnosis the maker has already written down.

Trouble codes named on this system

P0300 P12A6 P1098 P0016 P0106 P0442 P0455 P0201

Codes a bulletin or an owner’s complaint about the 2021 GMC Sierra names on this model year; a code with a record of its own links it.

Other systems with a record on the 2021 GMC Sierra

Source: the same files

transmission and drivetrain problems 139 complaints
electrical problems 76 complaints

From here

Every 2027 model on file, by price Compare two vehicles, trim vs trim See what a VIN was priced at See what owners reported

Common questions

Source: NHTSA complaint database, recalls and manufacturer communications

Are engine problems common on the 2021 GMC Sierra?

They are documented: NHTSA holds 355 owner complaints naming the engine on this model year (62% of everything owners filed about it), and 440 manufacturer bulletins, 1 recall, 4 NHTSA investigations are filed under the same heading. Whether it is a problem on one particular car is a diagnosis, not a count, and a count says nothing about how many were sold.

Is there a recall for the engine on the 2021 GMC Sierra?

Yes — one campaign is filed under this heading: 25V274000. A recall is matched by VIN; check yours at nhtsa.gov/recalls.

When do engine problems show up on the 2021 GMC Sierra?

Owners who gave an odometer reading reported it at a median of 58,522 miles; half of them between 35,000 and 83,000. That is when reports cluster, not the life of a part.

What does NHTSA's "Engine" heading cover?

The engine and its cooling system. Owners choose the heading when they file, so it says which area of the vehicle the complaint is about, not which part failed.