2021 Honda Accord Engine Problems

Your 2021 Honda Accord's engine is losing coolant rapidly — you need to refill it every two weeks. You've already had the head gasket and cylinder head repaired at a Honda dealership, but the coolant loss continues. The dealership is still investigating the issue, but this could lead to engine overheating, which is a serious safety risk. The repair will likely involve diagnosing and fixing the cooling system, possibly including another head gasket replacement or engine work.

Your car suddenly developed a severe misfire in cylinder 2, causing rough idling, multiple warning lights including a flashing check engine light, and loss of power while driving — forcing you to coast to safety. A mechanic initially replaced the coil and spark plug, but the problem returned. The dealership diagnosed a faulty head gasket between cylinder 2 and the water jacket, quoting $5,998 for repairs. The fix will require removing the cylinder head and replacing the faulty head gasket.

Your car's warning lights all came on and it wouldn't accelerate properly. The dealership diagnosed a blown head gasket, which they said is a known issue affecting 1.5-liter turbocharged Honda vehicles. You also mentioned two additional known problems with these cars that Honda hasn't addressed. Fixing a blown head gasket typically requires removing the engine head and replacing the gasket seal.

When you start your car in cold weather, you immediately notice rough, shaky engine operation along with a flashing check engine light. You've also noticed some coolant loss and white smoke coming from the engine. A diagnostic scan revealed a cylinder #2 misfire code, which means that cylinder isn't firing properly. This will likely require spark plug replacement, ignition coil inspection, or fuel injector service to restore proper engine operation.

Your head gasket failed at 100,000 miles while you were driving on the highway, causing your car to lose power and slow down from 65 mph to 35 mph. A blown head gasket allows coolant and oil to leak internally, reducing engine performance and potentially causing overheating. The repair will require removing the cylinder head and replacing the gasket, along with checking for any additional engine damage.

Your engine's timing chain has stretched and required replacement at 86,000 miles, costing $2,400. This is reported to be a common issue in 1.5T engines. The timing chain controls the synchronization of your engine's internal components, and when it stretches, it can cause the engine to run poorly or fail entirely.

The contact's girlfriend owns a 2021 Honda Accord. The contact stated that while his girlfriend was driving at an undisclosed speed, the check engine warning light and several other unknown warning lights illuminated. Additionally, the contact stated that the engine was slightly misfiring while driving. An independent mechanic replaced the spark plugs and the ignition coils at the residence; however, the failure recurred 3 weeks later. The mechanic inspected the vehicle but could not determine the cause of the failure. The vehicle was taken to the dealer, where it was diagnosed with head gasket and fuel injector failure. The contact was provided an estimate for the repair. The vehicle was not repaired due to the cost. The manufacturer was not notified of the failure. The failure mileage was approximately 74,000.

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. No warnings preceded the incident,

The contact owns a 2021 Honda Accord. The contact stated that while her son was driving at an undisclosed speed, the vehicle experienced a loss of automotive power and stalled. The vehicle was towed to the local dealer who diagnosed the vehicle and determined that the head gasket was blown. The vehicle was not repaired. The manufacturer was not yet contacted. The failure mileage was unknown.

Head gasket blown before 50k miles even at 30k miles ive seen it happen to my friend!

While driving in heavy rain on interstate, vehicle experienced lack of power and flashing check engine light. Driver was unable to maintain speed. Pulled off at next exit and turned off. Roadside assistance was contacted immediately after pulling off. Vehicle restarted and ran normally after allowing it to remain off for approximately 1.5 hr. Roadside assistance was cancelled. Continued trip without further incident.