2020 Honda Odyssey Engine Problems

Following replacement of the small block in Dec. 2025 for bad pushrod bearings. The vehicle ran for 3000 miles, before the engine seized up again while driving at 50 mph. The vehicle came to a stop in the travel lanes and could not be moved due to engine failure. Upon having the vehicle towed back to the dealership for inspection and repair, they found that the #3 cylinder had both valves broken and metal pieces shavings found in the engine. The dealer claimed that this was not related to the previous replacement of the small block as they did not work on the headers. However I believe the original issue of the bad pushrod bearings caused poor oil flow to the headers and the valves were already worn before the Dec. 2025 engine seizure. The dealer has now replaced the small block (for a 2nd time) headers, intake manifold, injectors and timing chain.

My wife started hearing a knocking sound while driving, coming from under the hood. I opened the hood while the engine was idling and could tell the sound was coming from inside the engine. Checked the oil level and it was in the operating range and looked clean. I had just changed the oil and filter 08/2025. After that we immediately drove it to the Honda dealer where we purchased the vehicle and the service manager heard the noise, checked for recalls, but could only find the recall for the 2019 Honda Odyssey [XXX] The service manager called in one of his mechanics to listen to the noise in the service manager bay and he said, "Sounds like a bad rod bearing". They then took the vehicle to inspect it further in the mechanic's garage, but as they were pulling it into the bay the engine complete seized up. The vehicle only has 68k miles on it, but now its beyond the warranty period. I was also told by the dealer when I purchased it, that it and the 2019 are identical, so why was the recall issued for the 2019 Odyssey, but not the 2020 model? I'm reading lots of similar reports of this same exact issue with the 2020 model from Honda forums and on youtube posts. This engine problem is clearly larger than the initial recall that was issued in 2024. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Connecting rod bearing failure at 105,000 miles, even with full recommended and documented service history.

I was driving with family to a family trip up to the mountains to enjoy the snow when at a rest area I noticed the odyssey just had a slight delay to turning on before continuing the trip. No lights no signs of anything going wrong. As we continued our trip back onto the freeway on a curvy road and night time the odyssey didn’t want to shift gears wouldn’t speed up for freeway traffic. Immediately started pulling over. The odyssey would make like jerking movements decided to call the tow truck and it quickly escalated to draining the battery. After being at the tow facility for one night it completely didn’t want to even turn on next day. Put a new battery and still drains the battery. I took it to Honda service to run a diagnostic and they come back saying the engine is seized. No lights no signs didn’t see this coming with only 87,000 miles. With a black screen displaying electrical issue at times.

In the past six months the Honda "auto-start" feature has caused my vehicle not to restart while stopped at an intersection. Honda needs to immediately recall all Gen 5 vehicles that use the auto-start feature and permanently disable (or give an option to disable) this useless, safety-affecting "feature". Thank you.

The contact owns a 2020 Honda Odyssey. The contact stated that while driving at an undisclosed speed, the vehicle inadvertently lost motive power. The contact was able to coast to the shoulder of the roadway, where the vehicle failed to restart. No warning lights were illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the connecting rod bearings, resulting in damages to the engine, causing the engine to seize. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 23V751000 (Engine and Engine Cooling), but the VIN was not included. The manufacturer was not notified of the failure. The failure mileage was 130,000.

Engine recently began making noise and the car was taken into Honda. The dealer checked engine components to find the cause and recommended that we remove oil pan to inspect the issue because they assumed it might be engine bearing related. Before we could schedule the service I was driving with my family on the highway when we heard a loud noise and complete loss of power. I was able to move over avoiding other cars to reach the shoulder and come to a stop. The car would not start or go into any gear. Car was towed to shop. What component or system failed or malfunctioned, and is it available for inspection upon request? The car has not been inspected yet. Currently at shop being evaluated. Has the problem been reproduced or confirmed by a dealer or independent service center? Engine was making noise at the dealership when it went for service. There was no concern made by dealer stating car was unsafe to drive. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Was inspected before the car broke down, but currently being evaluated by local shop. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? There was an unknown noise coming from the engine, and dealer stated they needed to remove oil pan to diagnose the noise but stated it could be bearing related. The dealership did not say the car was unsafe or should not be driven. Before we could look into the issue more the car broke down on the highway.

Honda has been serviced at Honda of Ames #190 since 2022. 2023 - Issues with the engine stalling when it goes into idle mode at a stop. September 2023 – contacted Honda of Ames, IA dealer. They indicated it’s the battery which will need replaced. Took the car to Interstate Battery on 9/26/2023 where it tested at 12.5 volts out of possible 12.6 volts. Then took the car to dealer who insisted it was an issue with the battery. Replaced battery for $391. Problem continued. In 2024 there was a recall re: a known issue with the engine idle functionality requiring a software update. Took the vehicle in for the software update. Complained to the dealer that I unnecessarily spent $390 on new battery when that wasn’t the issue. They refused to refund any money. Problem persisted. On 5/21/2025 the car was brought into dealership for 100k service. I complained again that the auto-idle feature still stalling. Was told that it's not a universal known problem, they don’t have a fix that he’s aware of other than to check the battery. I explained we’ve been through this before and brought up Sept 2023 battery situation. He stated that the quick/handheld battery testers are not reliable; repair shops have “the big testers in the back” that are more reliable – that is what they will test my battery on. I asked if they could turn off the feature permanently and was told no. When car was ready I was told that the battery life tested fine. They did a software upgrade and I will need to drive it and just see if the stall issue continues. He repeated that it’s not a “universal known problem” and there was nothing further he could do. 7/5/2025 – the auto-idle has stalled twice since the service on 5/21/2025. Stalling in an intersection, at a red light, bottom of an off-ramp, etc.i s a serious and highly concerning safety issue.

High pressure Fuel pump makes Loud noice. Fuel line vibrates. Check engine light on, Shows error code Low fuel pressue.

On [XXX], while driving my wife to the RDU airport, our Odyssey's engine failed to restart after an Auto Idle Stop (AIS) at a busy intersection in Greensboro. Instead of starting, the dashboard displayed a Collision Mitigation System Problem alert, the Drive ("D") indicator light started flashing, and then the dashboard displayed a "Shifting to Park: Apply Brake Pedal" message. We were stranded at a busy stoplight, at the front of a dedicated left-turn lane, unable to drive or shift to park as instructed. The only way to resolve the issue was to hold the Start/Stop button for several seconds to shut the vehicle off. And the vehicles behind us had to swerve around us because our malfunctioning vehicle was blocking the lane. This problem has recurred semi-regularly since [XXX], forcing us to manually disable the Auto Idle Stop feature on every drive to prevent being stranded in traffic. An independent mechanic found no stored diagnostic codes but identified relevant Honda Technical Service Bulletins (23-008 and 23-009) addressing similar AIS failures. A Honda service center misdiagnosed the issue as a faulty battery, but subsequent testing by the independent shop confirmed the battery was in excellent working order. The actual Auto Idle Stop malfunction remains undiagnosed. The vehicle and its Auto Idle Stop system remain available for inspection. This issue appears to be part of the ongoing NHTSA Engineering Analysis EA25-004. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact’s daughter-in-law owns a 2020 Honda Odyssey. The contact stated that while his daughter-in-law was driving at an undisclosed speed, there was an abnormal sound coming from the engine compartment. The contact stated that an unknown flashed on the instrument panel. The contact stated that the sound had become louder over time. The vehicle was taken to a certified mechanic who diagnosed the vehicle with engine failure and stated that the engine needed to be replaced. The vehicle was not repaired because the vehicle was no longer under warranty. The manufacturer was not made aware of the failure. The failure mileage was approximately 84,688.

I was driving with cruise control on and a car pulled in front of me and hit the brakes. My car reacted by hitting the brakes hard and the engine tried to recover but hiccupped and lost power and engine light flashed at me. I pulled over and when I started the car again there was a rattle that would get faster if i pressed the throttle. I was able to get back on the road and the throttle rattle was still there and now it started saying engine oil low. I pulled over, checked dipstick and it was fine. Engine oil low light continued to flash, so I went to a oil change place to have them look and change the oil and they reported nothing wrong. I left and continued driving and the rattle noise was still there, engine oil low was still there. Then i heart a loud pop and griding noise, lost all power and had to pull over. This time the car was dead. I had it towed to a mechanic who said had to be an internal defect in the engine from the factory.

Several engine failures, starting one month after purchase in September 2020. multiple system failures (all on video) leading to very poor acceleration and operation. No compression in engine and only able to go 20 mph. White-Allen Honda made four attempts to solve the matter over the course of two years. The dealer has had the car a total of 120 days. Then end of December 2024 then engine began making a knocking sound and I was told it needed at new engine, to the tune of $10,000.00. Then I see a recall for a similar issue but only up to 2019 Odysseys. Please help find resolution for this.

While stopped in preparation to make a left turn across traffic on a 4 lane road, our 2020 Honda Odyssey engine stalled- the engine idle stop function did not restart the engine as designed. We had to restart our car, but the car did not immediately restart, it took us 2-3 attempts. There was no prior warning or indication there was a problem. We could have easily been hit by another car, injuring my wife and children. Our system is available for inspection, we have not had it inspected yet.

My vehicle has the engine idle option and shuts the engine off when idle in traffic or at traffic lights, etc. There have been incidents where the engine doesn't just shut off but it powers off the entire car and doesn't want to turn back on. My battery is fine because i just had service done on it and they tested the battery and its 100% fine. This issue is not a battery issue for my car. I literally had PTSD when the car shut off though because it happened at a location on the roadway where i had previously been rear ended in another vehicle and after my car shut off this time - my anxiety was very high that day and i was literally shaking. I was scared not knowing what was wrong with my car.

When the car engages the Idle Stop feature and shuts the engine off, the engine does not restart immediately once the brake is released. This has happened multiple times but the last time a message appeared that said to change gears and restart the car. In the meantime the vehicle was in traffic and stopped for over a minute before it could be restarted. This put us in danger of a rear end collision as other cars were wanting to go.

The contact owned a 2020 Honda Odyssey. The contact stated that while driving at an undisclosed speed, the vehicle stalled without warning. The contact stated that the vehicle failed to restart. As a result, another vehicle crashed into the rear of the contact’s vehicle. The contact sustained injury to her neck and lower back that required medical attention. A police report was filed. The vehicle was towed to a tow lot and deemed a total loss by the insurance company. The dealer nor the manufacturer were notified of the failure. The failure mileage was approximately 28,800.

SOMETIMES (NO DISCERNIBLE PATTERN) AFTER STOPPING AT A RED LIGHT OR A STOP SIGN, THE CAR SHUTS OFF AND WILL NOT RESTART FOR SEVERAL MINUTES. THE HONDA SERVICE CENTER AT THE DEALER WHERE WE LEASED THE CAR SAID THEY HAVE HEARD OF SIMILAR PROBLEMS WITH NEWER MODEL HONDA ODYSSEYS AND HONDA PILOTS BUT THERE HAS BEEN NO FORMAL RECALL. THIS IS A CLEAR SAFETY HAZARD. THE BATTERY HAS BEEN TESTED AND IT IS FINE.THE MECHANICS CANNOT FIND ANYTHING WRONG WITH THE CAR.

Several times the van has failed to restart from an idle stop/start at a red light and in the middle of stopped traffic. Several attempts to restart the van fail (van doesn’t even try to start) normally after a few minutes with the van back in park it will start again. Very dangerous to be frequently left stranded in the middle of the road. Frequently when the van does successfully take off from a idle stop, you can tell it struggles and just barely is able to resume.

When the automatic start/stop feature turns the car off when the brake is fully depressed the Car will sometimes not restart as designed. Further, it is sometimes accompanied by the forward collision warning light coming on and shutting the car off.