I own a 2020 Acura MDX. On two separate occasions, the Auto Engine Idle Stop system failed to operate while depressing the accelerator pedal while at a stop. Several unknown warning lights were illuminated on the instrument panel. The vehicle shuts off and the I had to manually restart the vehicle after the failure. I have not contacted the dealer yet but based on what I have found here I am not the only one that this is happening too. It is awful to be stopped in rush hour traffic and having people honking at me and potentially be the cause of an accident. The vehicle has not been repaired. The failure mileage was approximately 35,000 and 38,000 miles.
2020 Acura MDX engine complaints
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The contact owns a 2020 Acura MDX. The contact stated that on three separate occasions, the Auto Engine Idle Stop system failed to operate while depressing the accelerator pedal while at a stop. The contact stated that several unknown warning lights were illuminated on the instrument panel. The contact stated that the vehicle shut off and the contact had to manually restart the vehicle after the failure. The contact called and informed the dealer of the failure. The contact was then referred to the manufacturer for assistance with the repair. The contact was provided a case number and referred to the dealer to order the part for the repair. The contact made multiple attempts to reach the dealer but had not received a response. The vehicle was not repaired. The failure mileage was approximately 44,000.
When idle stop is on and I come to a stop, the car shuts off and switches to neutral. It has to be put in park to start it back up. This is a safety concern because the vehicle is essentially stalled until you're able to put it in parked and restart it, which could cause an accident. The dealer is aware of the problem as it's been discussed the last two times that I've taken my vehicle in for recalls. According to the dealer, there is a recall for this issue but it's not for 2020 MDX, it's for 2022-2025.
I am writing to formally express my concern regarding a recurring issue with the Auto Start/Stop feature in my 2020 Acura MDX. This feature, which is intended to improve fuel efficiency, has instead caused unexpected and unsafe engine shutoffs while the vehicle is in operation. On multiple occasions, the vehicle has failed to restart promptly after the engine shuts off at a stoplight or in traffic, creating a serious safety hazard. The delay or failure to restart can leave the car temporarily disabled in active traffic, placing both myself and other drivers at risk.
At 101,841 miles, noticed ticking coming from the engine as it was idling. Acura of Limerick dealership diagnosed the issue coming from the bottom of the engine as a rod knock. They feel the problem is internal to the engine and suggest replacing the engine at my, I the owner's cost. After reviewing blogs and information on recalls on the internet, this issue seems in line with other rod bearing issues with this 3.5L V6 engine. But my Vin is not identified as having the recall issue? This seems incorrect as my Vin should be covered as it seems to be the same problem.
Auto Idle Stop issue where engine did not restart. Occurred multiple times in April/May of 2024 and Vehicle Stability Assist Code U3006-16 appeared on the Infotainment screen. Taken to dealer who was unable to replicate the problem. The U3006-16 code appeared again in February 2025 but the car did not experience the restart issue at that time. The U3006-16 code appeared again on April 6, 2025 while exiting a freeway after a 20 minute drive and the engine did not restart after Auto Idle Stop engaged at the second intersection. Taken to dealer and unable to replicate the problem and supposedly cleared the codes. On May 21, 2025 the U3006-16 code appeared again while exiting a freeway after a one hour drive but the car did not experience the restart issue at that time. Took car to dealer who checked a bunch of things and cleared the code,
The contact owns a 2020 Acura MDX. The contact received notification of the federal safety agency Campaign Number: 23V751000 (Engine and Engine Cooling); however, the part to do the recall repair was not yet available. The local dealer was contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
My car has been going into neutral when in the autostop. The only way to get out of it is to turn it off and back on. It's incredibly dangerous. I almost got into a horrible accident. It happens suddenly and without warning.
Email Acura did an update to software for vehicle stalling, but the problem isn't fixed. I have notified the dealer twice and no return call. I am a widow, travel alone and am afraid this vehicle will fail when I'm alone. I was slowing to stop at a stop sign and the car just shut off.
I stopped at a red light and when I went to pull of the car cut off. I had to restart the car to pull off. This is the second time that this has happened.
My Acura MDX 2020 had an issue in which the automatic start-stop system sometimes not manage to start the engine after stopping.
When using the a/c while the Auto Idle Stop is engaged, the engine will shut off and not restart. This issue does not happen immediately, at the first cycle of being activated, it's after 3 or more cycles of the AIS being in use, like driving in stop and go traffic for instance. The issue reminds me of a low/dying battery when it happens. Now when I turn off the A/C, the car starts right up like normal. Also if I don't use the A/C, the AIS cycles like normal, like in traffic, l'll have no problems with its performance.
Hi, My 2020 Acura MDX has a problem with a Start/Stop sytem malfunction, sometime it fails to start after start/stop system activated either at the stop sign, red light or non moving traffic on the highway. I have to put it to the park and restart my car. It is very unsafe.
The contact owns a 2020 Acura MDX. The contact received notification of the federal safety agency Campaign Number: 23V751000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
The contact owns a 2020 Acura MDX. The contact received notifications of the federal safety agency Campaign Numbers: 23V858000 (Fuel System, Gasoline) and 23V751000 (Engine and Engine Cooling); however, the parts to do the recall repairs were not yet available. The contact stated that the vehicle stalled while driving and came to a complete stop on two occasions. The vehicle was able to restart, and the contact resumed driving. Additionally, the contact stated that the vehicle was difficult to start. There was no warning light illuminated. The vehicle was taken to the dealer, where it was confirmed that the battery was in good condition. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repairs. The manufacturer was not made aware of the failure. The failure mileage was approximately 25,000. Parts distribution disconnect.
This is the third time this has happened to me and I am very concerned and will be taking my car to Acura YET AGAIN for a checkup. I was driving with my kids in the car and stopped at a red light. When the light changed, I put my foot on the gas and noticed that my car would not move. That’s when I looked down and saw that the car was in neutral. I tried to put it back in drive and it kept telling me to “Shift to Park” and would not let me shift. I panicked as I had several cars behind me on a very busy road but I put my emergency lights on to signal that my car was not operable. After trying again 3 times and turning the car off completely/using keys to lock/unlock doors, it finally turned on and I could drive it again. I took my car to Acura about this in the past and they advised they could not replicate the error and that it was most likely my battery. My battery was changed and I’ve had this happen 2 times again.
Driving on the highway when suddenly I had lost all power and then the check engine light flashed. I was stranded for hours waiting for.a tow truck and freezing temperatures with no power to my vehicle. It was towed to the nearest Honda dealer and was told I had a complete engine failure and needed a new engine for $10,000.
I had purchased this vehicle and was not aware there was a stop sale on this vehicle model. I took the 2020 MDX to the dealer to get the recall service done, the connecting rod bearing and fuel pump issues. They were done back in March of 2024, j had taken the vehicle back to the dealer over 5 times for issues with stalling and trouble turning back on as well as engine noise, ticking and stalling. The dealer “cannot replicate” the noise all of sudden, but was initially able to hear the noise and stated “ it’s probably fine, but bring it in if it gets worse” this issue happened after the recall service was performed and the vehicle has never been correct since, I believe there is engine damage caused by the needed recall service.
We were traveling far from home on I-44 in Missouri when our 2020 Acura MDX experienced a total engine failure. An engine rod broke and pierced the oil pan causing a sudden loss of engine power. I believe this is related to the federal safety agency Investigation #RQ24013, even though the Acura dealership had performed the recall service for this issue a couple months earlier. I suspect the recall service was either performed incorrectly or that a part was not tightened properly, ultimately leading to the engine failure.
The contact owns a 2020 Acura MDX. The contact received notification of the federal safety agency Campaign Number: 23V751000 (Engine and Engine Cooling); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.
There is a clear engine knock. I have a recording of it both on video and audio, my engine performance and gas mileage has gotten worse. I picked up on the sound about 6 weeks ago and called (Mueller Acura), said I would have it checked at the next oil change. The dealer (Mueller Acura of Merrillville) has had my Acura MDX, for two days two weeks ago and for the last 7 days, currently. The didn’t tear down the engine completely. But they told me they had their master mechanic and Honda’s (from another shop Team Honda) Master mechanic came down and used a camera and I have a bad tensioner, bad rockers, and a bad cam shaft. I’ve been speaking with an outside mechanic who is a Honda certified Master mechanic who now runs an independent shop. Acura, says I have a bad camshaft, bad rockers, and bad tensioner. They said I need all of those replaced as well as the $3000 100K service. They are deeply discounting what they quoted me because I’ve documented well and made so many trips out there to physically show them the engine knock (right now they want $3606 to fix and then they will listen again). They finally heard it at the back of the engine. I’m in a rental and it’s costing me daily. The independent shop says the correct answer is you have a bad engine and they need to check the crank shaft, the head, and the rod bearings, in addition. He said if I changed the oil myself I would probably see metal particles in the oil and if I fix it I’m wasting my money as the entire engine is in need of replacement. It only has 86K miles on it and should not have these issues. I don’t think I should have to pay, and I need my vehicle back. I’m now without a vehicle and they are demanding I give them an answer by Monday at 7am on whether or not I’m fixing it. They won’t put anything in writing as they want to keep it kept quiet until I make a decision. The service manager is now trying to talk me into trading but not at their dealership. I feel like May need to contact an attorney.
My car is producing a loud noise from the engine bay, which closely resembles the sound of a failing crankshaft. I have taken the vehicle to the dealership several times, but they were unable to determine the source of the noise. I consulted with an experienced mechanic who advised me that the engine is likely to fail soon if the issue is not addressed. He recommended inspecting the internal components of the engine, specifically the crankshaft, for potential faults. I am not sure if the official dealership can check my engine for a faulty crankshaft.
I started to here a very light knocking noise on cold starts. I made an appointment with my dealership to check it out. The earliest appoint they had open was a bout a week out. A few days later I was driving on the highway and the knocking noise suddenly became very loud and all the dashboard lights came on. The vehicle lost power and I barely coasted off the highway before the MDX came to a complete stop. I called AAA and had the car towed to the dealer. The next day they called me and told me it had been a connecting rod bearing failure and needed an entire new engine for $25,000.00. I was in total shock. I googled what happened to me online and found this is happening to many acuras and hondas. The dealer said there is absolutely no warranty and they cant do anything even though there are articles online and from the federal safety agency saying this is a common problem and under investigation. I was forced to replace the engine in my car because I still have a loan on it and dont know what else to do. The engine basically blew up on the highway in heavy traffic and was extremely dangerous and now acura wants nothing to do with the repairs. I think this situation deserves investigation.
My vehicle stalled and the engine cut while I was waiting at a stop light. The engine auto shut-off feature was active at the time of the incident. While sitting a the red light the auto engine feature shut the engine down, which is normal to reserve the use of fuel while at a stop light. When I took my foot off the brake, the vehicle should have restarted. but instead, the vehicle went into N (neutral) and the engine did not restart. I was sitting in the middle of traffic with cars behind me, so I put the emergency signal on, I then put it in P (park) and started the vehicle. This is the second time this has happened. The first time I thought I touched the neutral button by mistake. There were no injuries, but I'm concerned that this could cause a crash in the future,.
I came to a stop at a stop sign. The start/stop feature activated and the engine shut off. When I lifted my foot off the brake, the engine did not restart (as it's supposed to), and then vehicle automatically shifted itself into neutral (without any of my doing). I put the emergency flashers on to alert other motorists, hoping to avoid a rear-end collision as I was stopped in the middle of an intersection in rush hour traffic. At this time, the battery light illuminated. The engine light illluminated as well. I had to forcefully and unusually push the brakew pedal towards the floor as the vehicle was drifting backwards. At this time, the vehicle would not shift into park. Then "PARK" illuminated, so I attempted to reapply the brake hoping that when I let up from the brake the car would start again (like the usual procedure). The vehicle then shifted into park, but the engine had not restarted. I pressed the on/off red button to follow normal procedures for turning the vehicle off. With my foot remaining on the brake, I pressed the off/on red button to start the engine as usual and the engine finally restarted. Afraid for the safety for myself and other motorists, I put the vehicle into drive and I pushed the button to stop the stop/start system from engaging. No codes generated during this. This is a safety issue for several reasons. First, I was stuck in the middle of a busy intersection where a large volume of cars travel through each day. It was rush hour, so the roads couldn't be more filled. Someone coming around the corner who might not have been prepared to stop could have hit me. Likewise, I could have been hit while in the intersection. Secondly, once the vehicle failed to turn back on, the Washington Grove (Montgomery County Fire and Rescue Services - MCFRS) was responding to a vehicular file nearby on I-270 and had I not have been able to move in time, some of their vehicles likely wouldn't have made it through because my vehicle was blocking the lane.
Issue with Auto Idle Stop. I have had multiple instances of the auto idle stop kicking in and shutting the car off while I am at a stoplight. This has resulted in VERY close calls with me getting rear ended. I have taken the vehicle in to be inspected at an Acura dealership only to be told that they cannot replicate the issue. When this issue occurs, it takes about a minute to get the car working again. The dashboard lights up with a lot of different flashing lights. There was no warning prior to this issue occurring. You cannot permanently shut off the auto idle stop and I should not be expected to remember to do it every time I get into the vehicle. I am afraid that one day this will cause a bad car accident that will lead to myself or my family getting severely injured/killed as other drivers are not aware that the car won't be going. The most recent incident occurred last weekend.
The contact owns a 2020 Acura MDX. The contact stated while driving 65 MPH and attempting to stop, the brake pedal was depressed; however, the vehicle failed to respond, and the engine shut off unintendedly. The “Idle Stop” message was displayed on the instrument panel. The vehicle was not taken to be diagnosed or repaired. The manufacturer was notified of the failure. The approximate failure mileage was 54,000.
Auto Idle Mode - After we've stopped and released the brake to go forward, the car will then shift to neutral by itself instead of restarting to drive. This has happened frequently and is now starting to happen more often. This is a safety issue, especially if you're the last car in line and other cars are traveling 55-60 miles behind you on a major road and see a green light ahead. Each time this happens, we have to turn off the car and try to restart the car, and sometimes this has been iffy and we've had to repeat the process a couple of times. There were no warning lights of problems with any of car components. There have been similar reports of this occurring: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
The auto idle engine stop malfuctions routinely shutting the engine off completely and requiring the driver to engage PARK, hit STOP, and RESTART engine before engaging DRIVE to proceed. We have experienced several near miss accidents or potentially caused accidents because drivers behind you have no idea what is going on. This issue is not just at stop lights but also interstate driving where traffic comes to a complete stop. I requested my Acura dealer permanantly disable this feature- they declined - I believe because it is an "Emission" feature that has gone wrong. I have seen "hack" options on line to disable this feature but fear for my safety - either way.
My MDX will randomly shut itself off while at a red light. It takes MULTIPLE attempts to get it restarted. The vehicle is available for inspection upon request. My safety and the safety of others was put at risk and continues to be at risk! This has happened at a highway red light multiple times. I am impeding the flow of traffic at an intersection with EIGHT lanes and FOUR lanes cross traffic. People move through this intersection extremely fast. This puts me at risk of causing an accident, injury the occupants of my vehicle and the occupants of the other involved vehicles. There is no warning as to when this will occur and there are no warnings at the time of the actual event either. I called the dealership and the service department acknowledged there have been others with the same issue. Acura is aware of the issue yet there is NO RECALL?? There is a Service Bulletin issued January 2023 by Acura admitting to the issue and it shows how Acura will resolve the issue for affected vehicles. If Acura is aware of the issue and the dangers of it, why have they not issued a recall to rectify the situation? The vehicle has not been inspected by the manufacturer, police, insurance representatives or others. I have a service appointment with the local dealership. There are no warning lamps, messages or other symptoms prior to the failure. The first occurrence was about four months ago. The second occurred three months ago. It occurred again today. THIS IS AN ACCIDENT AND LAWSUIT WAITING TO HAPPEN. SOMEONE COULD BE SERIOUSLY INJURED OR KILLED DUE TO ACURA’S NEGLIGENCE!!!
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