2019 Honda Accord Hybrid: misfire or rough idle

Filed Sep 9, 2026 · Engine, Transmission · OH

The vehicle has a documented, severe manufacturing defect involving a cylinder head gasket leak under Honda Service Bulletin 26-006. A certified technician at Honda East Cincinnati confirmed the head gasket leak in writing on September 9, 2026. Prior to this, an independent facility pulled code P0302 (Cylinder 2 Misfire) and used a digital borescope to capture video proof of liquid coolant pooling inside Cylinder #2. Despite written documentation from both facilities confirming an active internal engine leak, American Honda Corporate and the dealership are refusing to honor the warranty extension. They are requiring me to continue driving an unstable vehicle until it actively throws a code on a proprietary dealership scanner. Forcing a consumer to drive a vehicle with a known, documented internal coolant leak risks sudden engine seizure, overheating, and catastrophic stalling on public highways, creating a severe and preventable crash hazard.

Filed May 7, 2026 · Engine · 136,000 miles · SC

The contact owns a 2019 Honda Accord. The contact stated that while driving at an undisclosed speed the vehilce intermediately misfired due to oil leak. No warning lights were illuminated The vehicle was taken to the local where it was diagnosed the head gasket needed to be replaced. The vehicle was not repaired. The manufacturer was contacted but no assistance was provided. The failure mileage was approximately 136,000.

Filed May 5, 2026 · Electrical, Engine · CA

Vehicle was being driven on the highway when suddenly engine hesitated and started stalling. Speed was reduced from around 65MPH down to the low 40s. Cars were stacking up behind and passing, causing potential hazardous conditions. Vehicle was taken to a mechanic shop and diagnosed with misfiring, after reading OBD II with many alerts coming on. Further diagnostics revealed cylinder head gasket was leaking coolant into engine, as shown by borescope images. This is a known problem on 2018-2020 Honda Accords with both 1.5T & 2.0 engines. The multiple alert messages started to come on a few weeks ago, but the engine hesitation and stalling just started this week. At first we suspected a 12V battery issue, but testing confirmed battery was at 12.8V with no issues.

Filed Mar 9, 2026 · Acceleration, Electrical · CA

1. Component: The engine head gasket and the combustion system (specifically Cylinder 2). Specifics: A leak-down test confirmed a failure in Cylinder 2, leading to coolant intrusion. This was initially masked by a water pump code, but after the water pump was replaced and the code returned, a borescope confirmed "clean" pistons (steam-cleaned by coolant) and tap scarring. Availability: Yes, the vehicle and all diagnostic records are available for inspection. 2. Emergency Maneuvers: On multiple occasions, the car entered "Limp Mode" while driving 70–75 mph on the freeway. This caused a sudden, dangerous drop in speed, forcing me to maneuver through high-speed traffic to reach the median/suicide lane. Stranded: The vehicle overheated 5 times in one trip, leaving me vulnerable on the side of a busy freeway. 3. Yes. An independent shop confirmed the failure via a leak-down test, a borescope inspection, and physical analysis of the spark plugs. They confirmed that despite the computer throwing a water pump code, the mechanical failure is the head gasket. 4.Status: It has been inspected by an independent service center. I am now using their findings to pursue a lawsuit/claim against Honda for selling a vehicle with a pre-existing internal engine defect. 5. Timeline: Symptoms began in April 2024 (two months after purchase). Initial Signs: An "Emission System" warning light appeared. The diagnostic code indicated a water pump failure, which was replaced in April. Recurring Symptoms: In November, the car suffered multiple misfires and "Limp Mode." In March, the "Emission System" light and the same water pump code returned, but the shop confirmed the pump was functional and the true cause was the head gasket leak into the cylinders.

Filed Feb 24, 2026 · Engine, Fuel system · CA

City street driving speed < 35-40 mph, engine began rough idling at stop light after traveling just 1/8 mile. After driving less than 1 mile on level ground, engine slowed and would not accelerate above 20 mph. After another mile or so, increasing uphill grade caused speed to slow to 12-14 mph. Stepping on gas caused car to slow down even more, with shaking and jerky stop-start of vehicle. Maintaining 10-12 mph permitted vehicle to continue uphill climb for a few more miles so I could reach home. Downhill coasting was smooth with no gas pedal acceleration. Overnight parked in garage, and no problems driving vehicle to local independent auto mechanic. They were able to duplicate problem after 2 days and multiple test drives. Diagnosed permanent and temporary engine codes: misfires of cylinders 1 and 4 with ignition coil malfunction, misfires of cylinders 1, 2, 4, and random misfires. Also permanent codes: antilock brake ECM Failure, electric power steering vehicle stability assist System Malfunction, electric servo brake electric power train System Malfunction. Mechanic removed coils and spark plugs, found cylinder 4 has moisture. Coils, plugs cleaned and re-installed. Honda Dealer unable to duplicate problem after 3 days.

Filed Jul 29, 2025 · Engine · WA

Component or System Failed: The head gasket appears to have failed, leading to coolant leaking into cylinder 4. This has been confirmed by two separate service centers. The vehicle is currently available for inspection if needed. Safety Risk: The failure caused engine misfires and dashboard warning lights to activate while driving, which could have led to a sudden loss of power or control. I had to pull over and restart the vehicle to regain drivability, which put my safety and that of others at risk. Reproduced or Confirmed by a Dealer or Service Center: Yes. The issue was first diagnosed by Honda of Sumner, who initially suspected a compression issue. Their master mechanic later confirmed it was likely a head gasket failure. A second opinion from Greg’s Japanese Auto confirmed the diagnosis and provided photos showing coolant in the cylinder. Inspected by Manufacturer or Others: Yes. The vehicle was inspected by Honda of Sumner and Greg’s Japanese Auto. No inspection has been done by police or insurance representatives. Warning Lamps or Symptoms Before Failure: Yes. After a recent service (which included an AC repair, fuel pump recall, and oil change), I experienced two misfires in cylinder 4 within 24 hours. All dashboard warning lights came on during one of the incidents. These symptoms began four days after the service. Additional Context: I was quoted $8,100 for the head gasket repair by Honda. I believe this issue could have been detected earlier during the diagnostic service. I’ve since learned of a class action lawsuit involving this exact issue in my vehicle’s generation, which makes me concerned this is a known defect.

Filed May 14, 2023 · Engine, Fuel system · CT

On 6/14/22 and 3/29/23, my 2019 Honda Accord EX Hybrid had engine misfirings which lead to total loss of power on Rt 15 in NY and CT: 6/14/22: Upon entering highway, car bucked during acceleration and lost all propulsion coasting to a stop. Check again light was on and blinking. After reseating gas cap car driven directly to dealer for diagnostic. Car computer did NOT retain any error codes even though engine light was blinking. Dealer did not do any repairs. 3/29/23: Near end of 30 minutes in stop and go traffic, car began to hesitate when inching forward. When accelerating to travel speed, car bucked during acceleration and lost all propulsion coasting to a stop. Check again light was on and blinking. After reseating gas cap car driven directly to dealer for diagnostic. Car computer did NOT retain any error codes even though engine light was blinking. Dealer did not do any repairs. If check engine light indicates get service soon and a blinking light means get it immediately, then there appears to be an issue with Honda's computer diagnostic for not retaining codes. Also the propulsion system for failing which could possibly create safety issues for drivers of this vehicle. I traded the vehicle in for safety purposes and was forced to purchase a new vehicle much earlier than expected.

Filed Nov 20, 2021 · Electrical, Engine · OH

Vehicle repeatedly experiences a "cylinder misfire error" when driving above 45 mph. The check engine light will flash and the car surges like it is stalling. Loss of the ability to accelerate when it occurs. Also, the car shakes violently when the vehicle comes to a stop before turning off the engine. Many times, after restarting problem temporarily stops. I have taken it to the dealership multiple times, but problem is unsolved. Happens at least once a week. Started at 58,000 miles. More recently, the vehicle experiences a safety system failure when driving above 45 mph. 10 system warning lights were activated and will continually appear on instrument panel. Warning lights activated: 1. Hill Start Assist Problem 2. Adaptive Cruise Control System Problem 3. Collision Mitigation Braking System Problem 4. Road Departure Mitigation System Problem 5. Emission System Problem 6. Tire Pressure Monitor System Problem 7.Brake System Problem 8. Electric Power Steering System Problem 9.Vehicle Stability Assist System Problem 10. Brake Hold System Problem