2021 Honda Accord engine problems

35 owner complaints filed with NHTSA name the engine on the 2021 Honda Accord — 15% of all complaints for this model year.

Engine complaints

15%

share of all complaints

—

median reported incident mileage

3 / 0

crash / fire reports

What owners report

“SUBJECT: A REQUEST FOR HONDA CORPORATE INVESTIGATION AND GOODWILL ASSISTANCE - 2021 HONDA ACCORD I am submitting a formal complaint regarding serious and recurring electrical and safety-related problems with my 2021 Honda Accord. 1. Numerous dashboard warning lights and safety-system warnings…”
filed Aug 25, 2026
“My car currently has displayed all lights on panel. Went to auto zone to have codes read, shows powertrain-description is code PO299 suggests turbocharger assembly. Safety is put at risk because all of the safety features are now disabled.”
filed Aug 18, 2026

Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.

Dealer Message - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire, and/or DTCs P0300 through P0304 stored.
AEBM08262026901 · Other · issued Aug 26, 2026
Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.
A26-003 · Service Bulletin/Repair Instructions · issued Aug 26, 2026
Service Bulletin - Oil leak at timing chain tensioner inspection cover due to possible insufficient sealant adhesion on inspection cover.
A25-074 · Service Bulletin/Repair Instructions · issued Jul 29, 2025