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Your vehicleHome›Honda›2021 Honda Accord› engine problems
Owner complaints · Engine

2021 Honda Accord engine problems

51 of the 293 complaints owners filed with NHTSA about the 2021 Honda Accord name the engine (NHTSA’s “Engine” heading — the engine and its cooling system). Filed under the same heading: 58 manufacturer bulletins. 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.

51 complaints 17% of this model year’s 3 reports a crash

What owners filed about the engine

Source: NHTSA complaint database
51complaints name the engine

3 of the 51 reports a crash · 0 a fire · 2 injuries. Self-reported, unverified.

Filed per year: 2021: 1 · 2023: 3 · 2024: 4 · 2025: 14 · 2026: 29

Too few of these complaints carry an odometer reading to say when the problem shows up.

17%of this model year’s complaints

293 complaints in all about the 2021 Honda Accord, 29 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: Honda Accord 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.

My vehicle is currently suffering a failed head gasket. I was alerted about this issue from local mechanics and friends way before it actually happened. I took it to services and regular maintenance even more frequently after that. However, it still failed no matter what.
Engine Mar 4, 2026 NHTSA owner report · ODI 11721881
Vehicle accelerated on its own and propelled the vehicle over a curb and into a building. This occured even though the gear shift was in the Park position. My grandchild and I were thrown forward as vehicle hit the building. Vehicle has not been inspected since incident occurred just yesterday, 11/20/2025.
Engine Nov 21, 2025 NHTSA owner report · ODI 11700745
The head gaskets are known to fail on the 10 generation accord. It failed on my 2021 Honda accord ex-l. I left work and while I was driving the dashboard lit up with every possible light. This was quickly followed by the vehicle losing power on the highway. I ultimately got it repaired by a Honda certified mechanic.
Engine Oct 25, 2025 NHTSA owner report · ODI 11695539
I hereby state that my 2021 Honda Accord has experienced major mechanical failures involving the transmission and head gasket. The vehicle began exhibiting mechanical issues including rough shifting, loss of power, and engine overheating.
Engine Oct 22, 2025 NHTSA owner report · ODI 11694898
Head Gasket Blown i had a diagnosis ran at the honda dealership and it came back as a blown gasket its Preventing me to accelerate whole on the highway im going at high speeds and it slows down like im slmming on brakes
Engine Oct 7, 2025 NHTSA owner report · ODI 11691826

What is on file about the engine

Source: NHTSA recalls, investigations and manufacturer communications

58 manufacturer bulletins filed under this heading

The 8 newest are listed (the model year’s page has its newest of every kind). Quote the document number at a service desk — it is a diagnosis the maker has already written down.

Trouble codes named on this system

P0172 P0300 P0304 P0420 P0299 P0301 P0302 P0303

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

Other systems with a record on the 2021 Honda Accord

Source: the same files
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 Honda Accord?

They are documented: NHTSA holds 51 owner complaints naming the engine on this model year (17% of everything owners filed about it), and 58 manufacturer bulletins 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 Honda Accord?

No recall campaign is filed under this heading for this model year (there are 4 filed under other headings). A bulletin is not a recall: it carries no federal duty to repair for free.

When do engine problems show up on the 2021 Honda Accord?

Too few of the complaints carry an odometer reading to say. The model year's page shows the mileage curve across every system where it can.

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.