Engine And Engine Cooling Problems of Acura MDX - part 1

As I was driving in a stop and go traffic jam, the vehicle would not go forward although I was pressing on the gas pedal, the engine stall and when it finally reacted after pressing it for the second time it went too fast that I couldn’t stop in time to avoid rear ending the other vehicle, the emergency braking system did not function properly either. This has happened multiple times even when I driven on highways and there’s incoming traffic and the engine goes on stall. But this time it led to an unavoidable accident. I have been concerned for a long time about this issue but I have never received a recall to remedy this problem.

See all problems of the 2017 Acura MDX 🔎.

My 2025 Acura Mdx a-spec advance (VIN [xxx]) twice failed to restart after the auto idle stop system shut the engine off — on xxx (~2:00 pm cdt) and again on October 10, 2026 (2:20 pm cdt). The vehicle was immobilized and would not restart. Sterling Acura of austin ([xxx]) diagnosed a failed starter on xxx: bench testing showed 9. 7 amp draw with voltage drop below 7. 3v. The dealer replaced the starter motor (part 31200-5mr-a03) under warranty, test drove 10+ miles, cleared codes, and verified the repair. A no-restart after auto idle stop leaves the vehicle without motive power in traffic, which is a safety hazard. This matches the subject of NHTSA engineering analysis ea25004 (no restart after auto start/stop engages, 2016–2025 Mdx). Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2025 Acura MDX 🔎.

Car is not staying on during traffic. Afraid to go in highway now.

See all problems of the 2020 Acura MDX 🔎.

On October 1, 2026 at approximately 5:45am, while driving my 2026 Acura Mdx, I stopped at a red traffic light on a busy street. The vehicle's auto idle stop system shut the engine off as designed. When the light turned green and I attempted to proceed, the engine failed to restart. The vehicle became disabled in an active traffic lane in the dark and I was unable to move it for several minutes. I attempted to restart the vehicle multiple times. It took several attempts to fully the shut the vehicle down and restart it before I was able to actually restart the car and resume driving. Because the vehicle was unexpectedly immobilized in traffic when surrounding vehicles began moving, I was placed at significant risk of being struck from behind or involved in a serious collision -- particularly because it was dark and all my lights were off while attempting to restart the car. My best assessment is that the failure involved the auto idle stop / restart system, starter system, electrical system or related control components. The exact cause is unknown at this time. The vehicle and all related components remain available for inspection upon request -- at least until the dealership starts working on my car to diagnose and hopefully fix the problem. (there are other reports of this happening with earlier models. ) there were no warning lights, warning messages or obvious symptoms immediately before the failure. The auto idle stop system appeared to operate normally when the engine shut off at the red light; the failure occurred when the system was supposed to restart the engine. The problem has not yet been reproduced or confirmed by my Acura dealer. I advised my dealership that the car failed to restart and left me stranded in active traffic. I was initially told that it could be several weeks to months before they could inspect the vehicle and I escalated the matter to the head of the service department due to the serious safety issue.

On multiple occasions while my car is stopped at a light or stop sign the idle restart stalls and the car shuts off. I need to give it a few minutes and restart the car. It mainly happens when the auto shut off for idling restarts. I have had it happen more than 10x with my kids in the car. I have done all required work - timing belt & water pump replacement, transmission fluid flush, new times and new suspension. It continues to get worse.

The auto idle stop has activated normally at traffic lights, but on two occasions the engine shut off and then failed to automatically restart when I released the brake. A yellow warning light with an exclamation mark also appeared on the dashboard. The most recent incident happened yesterday, 09/25/2026. There have also been several other times when the engine did restart, but it took noticeably more effort or longer than normal to restart from auto idle stop.

Car engine went into idle mode while the idle stop was engaged while stopped on an expressway off ramp. Car engine did not turn back on and entire car shut down. It took about 1 minute to re-start the car and engine. Safety was compromised because car shut off in an unsafe location. No accidents or injuries occurred. This happened about a year ago and car battery and starter were replaced by the Acura dealer November 2025. There were no warning lights or messages prior to this problem appearing. Prior to this event, car had been slow to turn over for about 1 week. I previously submitted a complaint to NHTSA in fall 2025, case #11694662, when this happened the first time.

Issue occurring with automatic start/stop function. Car stalls on occasion trying to restart, goes into neutral, even though battery is new and in good condition. Hard to replicate and occurs randomly. Car has to be turned off and on again. This is the 4th time this has happened over the course of 3 years. Seems to be happening to others based on forums as well.

See all problems of the 2019 Acura MDX 🔎.

I own a 2025 Acura Mdx a-spec purchased in xxx from john eagle Acura in [xxx]. The vehicle has less than 10,000 miles. Component/system: the auto idle stop/start system has malfunctioned. During the past week, the engine unexpectedly shut off while stopped at red lights and stop signs approximately 4–5 times. When it was supposed to restart, the vehicle sometimes failed to restart normally and required multiple attempts. The vehicle and components are available for inspection upon request. Safety risk: these incidents occurred at intersections while I was stopped in traffic. When the engine failed to restart, I was unable to immediately proceed while vehicles were behind me, creating a potential collision and traffic hazard. I regularly have my two young children in the vehicle, making this especially concerning. Dealer inspection: I brought the vehicle to john eagle Acura after experiencing the problem. The service advisor indicated that this is a known issue, and the vehicle was serviced for the concern. The failure occurred repeatedly in real-world driving, but I do not know whether the dealer was able to reproduce it during inspection. Manufacturer/other inspection: the vehicle was inspected by an authorized Acura dealership. It has not been inspected by police or insurance representatives. Warnings/symptoms: I received no prior notification or warning from Acura regarding this issue. The first incidents occurred during the week before my dealership visit. The engine shut off while stopped and then did not restart normally. I did not observe a warning lamp or message specifically indicating that the vehicle would fail to restart. After experiencing the problem, I learned that NHTSA has an ongoing investigation, ea25-004, involving auto idle stop failures on Honda and Acura vehicles, including 2023–2025 Acura Mdx models. I am submitting this complaint so these repeated incidents can be documented as part of NHTSA's review. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 5.

Heard a knocking noise in the engine, had it serviced at an independent mechanic (towed as to not create more damage and the knocking noise was louder). Mechanic told me that the rod bearing/engine had failed and would need to be replaced. $7000-$10000 for replacement. He also indicated that this was under recall for 2016-2020 cars. I checked my VIN and my car is not part of the recall but the car has 130000 miles and has been serviced regularly. I am requesting that it be part of the recall since this is a known/reported issue for this year/model. I called american Honda and they said because of the mileage and age, that it would not be part of the recall.

See all problems of the 2016 Acura MDX 🔎.

The contact owns a 2016 Acura Mdx. The contact stated that while driving approximately 50 mph, the vehicle suddenly lost motive power and failed to accelerate while the accelerator pedal was depressed. The check engine warning light illuminated. The contact stated that the failure posed a potential safety risk in daily traffic. The contact pulled over to the shoulder of the road, and the vehicle was towed to a local dealer for diagnosis. The dealer diagnosed the vehicle with engine bearing failure into the engine oil pan and cylinder #5 failure. The contact associated the failure with NHTSA campaign number: 23v751000 (engine and engine cooling) and NHTSA action number: pe25008 (engine). The manufacturer was notified of the failure by telephone. The failure mileage was approximately 150,000.

Engine seized multiple times. Completely broken now. Online it says many people have these problems.

The contact owns a 2020 Acura Mdx. The contact stated that while idling and driving on several occasions at various speeds, there was an abnormal knocking sound coming from the engine compartment. The vehicle was taken to an independent mechanic to be diagnosed. The mechanic determined that there was internal engine rod bearing failure, and that the engine needed to be replaced. The contact believed that the failure was associated with manufacturer recall number: 24-001. The manufacturer was notified of the failure. The failure mileage was 65,128.

My 2020 Acura Mdx has experienced repeated auto idle stop system malfunctions. When the system activates at a stop, the engine shuts off and does not return to normal operation as expected. The incidents are becoming more frequent and create a safety concern when the vehicle is stopped in traffic. This problem has been reported by telephone on multiple prior occasions. The 12-volt battery has also been replaced multiple times because we believed the battery was causing the problem, but the condition has continued.

I was driving w a passenger on a busy 4 lane road and trying to make a left turn. When I tried to hit the gas after coming to a stop, my car would not move. I did not know what was happening, as it turned out the car had shifted into park and turned off. Extremely dangerous scenario. I had to take my foot off the brake, restart the the car and put it in drive again to move. I brought it to the dealer the following day, they said they fixed it with a gear shield as the trans had dirt in it and a new starter. However, yesterday, prob about 6 or so months later it happened again. I went directly to the dealer. They kept the car over night. Today I was told the my battery charge was too low and the auto idle engine on/off turned off due to it being not having enough charge. Totally different excuse than the first time. Also, when I dropped it off I was told someone else had dropped their 2025 Mdx off that same day for the same reason. I am very concerned, worried and nervous when I drive it. It helps if I turn the auto on/off idle stop off, but I must do that every time I start the car as it resets each time the car is turned off. Obviously I forget sometimes. It is a major concern that I feel the dealership is not taking seriously or showing much concern for my safety. Thank you for your help.

"vehicle experienced a sudden flashing check engine light pulled over checked oil restarted car flashing check engine light went away then started flashing again a few miles down the road (cylinder 3 misfire) accompanied by severe engine knocking. The engine locked up/seized while hot. Car was stuck on the road and was unable to shift to neutral. After cooling down, the engine restarted but produces a heavy metallic scraping and loud squealing noise from internal friction. This matches the exact failure mechanism of connecting rod bearing failure under investigation pe25008, but Honda/Acura has excluded this VIN from active recalls. I was forced to pay $389 out-of-pocket for an emergency tow. ".

I have had a problem with the "auto idle stop" in my 2025 Acura Mdx. While at a stop light 2 different times and at a stop sign 1 time the car engine shut off as it should. Upon letting off the brake and pressing the gas the car would not go. It stayed in park and I could not get it to go. The engine would not turn back on. I received a warning light that said "depress brake and push start". Upon doing this the car still would not start. I had to open the door, shut door, push brake and then start the car. Dealer confirmed that this has been an issue.

I have a 2025 Acura Mdx sh-awd. Several times while stopped in traffic, the auto idle stop system shut the engine off and the vehicle displayed ‘restart engine. ’ the vehicle did not restart automatically. I'm concerned that this could cause a safety hazard if it happens in traffic. I want to file a safety complaint.

Idle auto start/stop will not restart after cutting on leaving me stranded in traffic.

The engine in the car caught fire and subsequently destroyed the vehicle. The car was parking in a shopping center parking lot at the time.

My 2025 Acura Mdx suffers from a severe safety defect regarding the auto idle stop (auto start-stop) system. When the vehicle comes to a complete stop at intersections or traffic lights, the engine shuts off as intended. However, upon releasing the brake pedal to accelerate, the engine completely fails to auto-restart. Instead of restarting, the vehicle drops out of the auto-restart sequence entirely, shifts itself out of drive, and displays a critical safety message on the dashboard: "to start engine: brake + push". This completely strands the vehicle in live traffic, forcing me to manually shift into park, press the foot brake, and push the engine start button while traffic accumulates behind me. This creates an immediate rear-end collision hazard. The dealership has already attempted to diagnose and repair this issue under warranty by replacing both the vehicle's battery. This hardware replacement did not fix the problem; the failure continues to occur unpredictably less than a week (and 25 miles) after replacement. The root cause appears to be a software, powertrain control module (pcm), or sensor tracking defect where the vehicle fails to recognize it is in an automated restart sequence. I am filing this complaint to be officially included in the ongoing NHTSA engineering analysis ea25004 regarding Honda/Acura auto idle stop failures, as the current hardware recall remedies are entirely ineffective for the 2025 model year.

2025 Acura Mdx – auto idle stop failure to restart when my 2025 Acura Mdx is stopped at a traffic light and the auto idle stop system activates, the engine shuts off but on multiple occasions has failed to restart when traffic begins moving. The vehicle becomes immobilized in an active traffic lane. Vehicles behind me begin moving and honking while I am unable to move the vehicle. To regain operation, I have had to completely shut the vehicle off and restart it while stopped in traffic. I can prevent the occurrence by manually disabling auto idle stop after starting the vehicle, but this requires me to remember to disable the system every time I drive. If I forget, I risk the vehicle shutting down and failing to restart at an intersection. This creates a serious safety concern for me and my passengers, including my child. I am concerned about being stranded in an intersection or other active traffic lane and potentially being struck by another vehicle. I believe the auto idle stop system's failure to restart the engine presents an unreasonable safety risk and should be investigated.

The contact owns a 2020 Acura Mdx. The contact stated that while driving approximately 35 mph, there was an abnormal knocking sound coming from the vehicle before the vehicle stalled. The vehicle failed to restart. The maintenance warning light was illuminated. The contact stated that the failure was associated with NHTSA campaign number: 23v751000 (engine and engine cooling). The vehicle was towed to the residence. The local dealer was contacted to schedule an appointment, but the vehicle had not been diagnosed or repaired. The manufacturer was not contacted. The approximate failure mileage was 60,541.

After an auto idle stop at a major intersection, car failed to restart automatically and was left stranded unable to restart the car. Car would not shut off or turn back on when using the power button and with foot on brake but had power but it was in limp mode - transmission warnings flashed and the d "for drive" on the screen at the drivers location. I called triplea however before they showed up I was able to put the parking brake on and turn the car off and on ad it reset. This is similar to the issue was happening with my 2017 Honda pilot where it would stall and not restart after the auto idle stop engaged. Very dangerous and difficult to troubleshoot when in that situation, surprised that this is still happening in Honda manufactured cars - this is very dangerous and needs to be addressed and investigated.

Engine turns off while in drive or stopped at a red light/stop sign. It has happened 7-10 times withing the last couple of months, but 3-4 times within the last week. Out of the four times it happened, my family's safety was at risk, because the car was in drive, and could've caused us to get into an accident. During the other occasions, we were moving in reverse and stopped at a stop sign. Complaint was made with Acura of bay shore in long island, NY, at which time an update of computer engine was performed but issue wasn't fixed due to back-order part that needs to be replaced. Unfortunately, just yesterday (August 13, 2026) car turned off at light causing a road hazard to vehicles and my family stuck in a large intersection. Multiple engine lights turned on, but I was unable to turn the car on or move it. Approximately 10 min later, I was able to turn the car on and move it to safe location. I spoke to Acura of bay shore, and it is a known issue but till this date, isn't fixed. Vehicle is a hazard and can cause serious bodily harm/or death. Thank you.

My vehicle is equipped with the auto stop, idle/start feature. I have had my vehicle completely shut off at least 6 times when I am at a complete stop. I have researched this problem among 2025 Acura Mdx owners and it seems to be a recurring problem. The feature is suppose to save gas when I am at a stop and shut down the engine and then restart when I press the gas pedal but that is not happening.

My vehicle was stopped at a busy intersection, idling in the automatic stop mode. When my husband moved his foot from the brake to the accelerator, the car stalled, orange alarm alerts went off, and the car was completely dead and stalled without power. The car needed to be restarted, and it took a few attempts to accomplish that task. I have had the same problem before with this car and have had it into the dealer at least two times without resolution.

Auto idle restart failed three times in traffic at red light. Have to shift to park and push start button. Nothing happens for several seconds, then engine starts.

The contact owns a 2025 Acura Mdx. The contact stated that while at a complete stop at a traffic light, the vehicle unexpectedly shut off and failed to restart. After approximately 15 minutes, the vehicle restarted, and the contact drove into a parking lot before driving to the residence. No warning lights illuminated. The dealer was notified of the failure the following day, and a service appointment was scheduled. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 14,000.

The vehicle intermittently fails to restart after the auto idle stop system shuts the engine off at a traffic stop. When this occurs, the vehicle remains disabled until it is manually restarted. This has now happened repeatedly, including twice within one recent week. The vehicle was purchased new on November 27, 2024, and currently has approximately 27,500 miles. The repair history for this same issue •September 19, 2025 — 13,841 miles: battery replaced. •January 27, 2026 — 18,481 miles: battery replaced again. •February 4, 2026 — 18,814 miles: starter replaced. •August 14, 2026 — approximately 27,500 miles: vehicle returned again for the same continuing problem. Diagnostics were performed, but no repair or resolution was provided. Despite replacement of two batteries and the starter, the defect continues. Our most recent experience with the dealership was particularly concerning. We were essentially told that they could not identify the problem and could not provide any further solution. That is not an acceptable outcome for a vehicle that can shut itself off while stopped in traffic and then fail to restart.

On August 3rd the vehicle began making a loud clicking/knocking noise from the engine area of the car. Took the car to richard bailey automotive on August 4th for diagnosis. Was informed a week later the engine needed replacement. Have owned the car for 3 months. No warning lights except to clean the backup camera. All maintenance has been performed on the vehicle.

On two occasions my vehicle stalled out when the idle stop feature failed to restart the engine in traffic. I could not restart my vehicle initially and it took several attempts to restart. Because I was at a stop in an intersection waiting to turn this could have resulted in a serious accident. There was no warning light or other indication of an issue prior to, during, or after the first incident. This was subsequently reproduced and documented with the dealer. They indicated they are seeing issues with many other vehicle of the same model and year but indicated they couldn't say much more. The dealer said they would replace the starter but did not definitively say it would solve the issue. Because they did not have the part in stock thet advised me to continue driving in the meantime with the idle stop feature disabled; however, operators must remember to do this manually at each drive.

The automatic engine shutoff turned off the engine three times at stop lights and failed to restart. We were left stranded in the middle of the road, cars zipping by us fast. We felt very much at risk of being hit.

I am writing to formally report a serious and recurring safety defect with my 2025 Acura Mdx a-spec (VIN 5j8ye1h06sl022053) involving the auto idle stop system. The engine repeatedly fails to restart after the auto idle stop feature shuts it off. When my wife releases the brake pedal (for example, at a traffic light), the vehicle either stalls completely or experiences a major delay before restarting sometimes lasting more than 20 seconds, leaving the my wife unable to accelerate. This creates an immediate and unacceptable safety hazard, particularly in intersections or heavy traffic. I previously brought the vehicle to Acura of langley regarding this exact issue. Despite that visit, the problem has continued. Most recently, on today, while my wife was driving with my kids, the vehicle again entered auto idle stop at a traffic light. When the light turned green, the engine completely shut off and would not restart for more than 20 seconds. This left her stranded in traffic and unable to move the vehicle, creating a clear risk of collision. This is not an isolated complaint. The national highway traffic safety administration (NHTSA) has opened engineering analysis ea25004 into precisely this condition “no restart after auto start/stop engages” affecting, among other models, 2016–2025 Acura Mdx vehicles. American Honda has also issued dealer communications specifically seeking 2023–2025 Mdx vehicles with client complaints of no auto re-start after auto idle stop for inspection prior to any repair attempts. Class-action investigations and prior litigation involving related idle stop failures further underscore the known nature and seriousness of this defect.

I am submitting this complaint regarding my **2025 Acura Mdx**, which I currently lease. The vehicle has an ongoing starting system malfunction that has not been resolved despite multiple service visits. I believe this issue presents a significant safety risk. The primary issue involves the **auto idle stop/auto start-stop system**. When the vehicle automatically shuts off at a red light, stop sign, or while idling, it will occasionally fail to restart when I release the brake or attempt to accelerate. Instead of restarting normally, the vehicle hesitates, stutters, or remains off. This creates a dangerous situation because the vehicle is unexpectedly disabled while in traffic, increasing the risk of being rear-ended or causing an accident. In addition to the auto idle stop issue, the vehicle also has problems during the initial startup. When I attempt to start the vehicle using the push-button ignition, it frequently fails to start on the first attempt. I often have to press the start button a second time before the engine starts, and even then, the engine stutters or hesitates before finally turning over. This should not occur in a brand-new 2025 vehicle. I have taken the vehicle to the dealership multiple times for this issue: * during the first visit, I was told the battery was the cause. * during the second visit, the starter was replaced. * after the problem continued, I returned again. The dealership tested both the battery and the replacement starter and advised that both components were operating properly. * the dealership then opened a case with Honda/Acura engineering for further investigation. Despite these repeated repair attempts, the issue remains unresolved. I have been told that it is likely a software issue and that engineers are "looking into it. " in the meantime, I was instructed to simply disable the auto idle stop feature every time I start the vehicle. This is not an acceptable solution. I do have videos but it will now allow me to up.