2020 Acura MDX Engine

On December 4th I noticed a rattling sound when I was driving. It worsened when my car would rev above 2RPMs and before shifting. It also would make a terrible grinding sound when I started the car. I had about 1/4 of a tank of gas and thought that maybe that was part of the issue. After filling up, the sound was not as loud, but was still present when I started the car and upon accelerating. I took my car to my Acura dealership on December 5th. Within an hour of having the car they called to tell me that the engine needed to be replaced due to a connecting rod failure. They told me that the car is no longer safe to drive and that the repairs would be required in order to continue to use the vehicle safely. There was no warning sign. My only other concern is that the downshifters of this vehicle have never worked properly. I have mentioned this to the dealership multiple times and even drove the vehicle with their representative to recreate the issue. The car would accelerate and lurch forward upon utilizing the downshift feature. This would also cause the vehicle to over-rev which I am concerned was problematic to the connecting rod failure. Additionally, the vehicle has always made a grinding noise upon starting the engine, but the dealership assured me this was normal. Acura is unwilling to cover the full cost of replacement even though this vehicle has been maintained per the manufacturer's recommendations. There are approximately 90,000 miles on this vehicle.

My 2020 model Acura MDX is experiencing unexpected engine shutdowns while braking during motion. The issue has been reported multiple times to the vehicle manufacturer and their authorized dealers; however, their responses have been consistently unhelpful and have not resolved the problem. I currently have an open complaint with American Honda Motor Co., Inc. since December 2023 Case Number: 14329512 Additionally, I have found numerous reports online from other owners of the same model experiencing the same issue, as documented here: 2020 Acura MDX Engine Complaints – CarComplaints.com This recurring malfunction presents a serious safety risk, especially in moderate traffic conditions, where sudden engine failure during braking could lead to collisions or injuries.

I was driving on the interstate when suddenly the check engine light began to flash and the car lost power. I was traveling at 70 mph and the sudden loss of power caused the vehicles behind me to move into the other lane to prevent rear ending me. While there was no accident, there could have been if the other drivers were not reactive. There was no advanced warning. This could have been deadly for me and my family. I was several miles from home and needed to have the vehicle towed to a mechanic who stated it sounded like a rod bearing and suggested we take it to an Acura dealer. We are yet to have a resolution.

The idle stop feature does not work correctly. A couple times the car did not restart while stopped at a red light. Had to put into park and took about a minute to restart.

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,

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.

The contact owns a 2020 Acura MDX. The contact received notification of NHTSA 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.

At a red light or stop sign, my MDX switches into Neutral without me knowing it. When I press the gas to go, my car won't move. Other vehicles behind me almost hit me as they expect me to go. I can't switch into drive. I must turn off car and then turn it back on. I feel this is very dangerous. This happens about once a week now. The MDX was just in for service and recalls a few months ago. Nothing was noted about the engine on the reports.

The contact owns a 2020 Acura MDX. The contact stated that occasionally, while driving at various speeds, the vehicle stalled. There was no warning light illuminated. Additionally, while the vehicle was stopped at a traffic light, the Auto Idle START/STOP failed to operate as designed, and the vehicle failed to restart. The vehicle was taken to a local dealer; however, the cause of the failure was unknown. Upon further investigation, the contact related the failure to an unknown recall; however, the VIN was not included. The manufacturer was made aware of the failure. The failure mileage was approximately 10,000.

The contact owns a 2020 Acura MDX. The contact stated that on several occasions, while coming to a stoplight, the vehicle lost motive power. There was no warning light illuminated. The vehicle was able to restart. The vehicle was taken to the dealer; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 46,000.

connecting rod bearing failure confirmed by independent mechanic. No alerts or warning lights. Problem just showed up and engine started knocking on acceleration.

On multiple occasions when the car is stopped at a light, in traffic or at a stop sign and the auto idle stop feature is engaged the car will shut off and not restart for up to 1 minute. We have always been able to get it to restart but feel it is dangerous to be stopped so long in moving traffic.

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.

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.

The contact owns a 2020 Acura MDX. The contact received notification of NHTSA 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.

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.

I own a 2020 Acura MDX. The Auto Engine Idle Stop system failed to operate while depressing the accelerator pedal while at a stoplight. The vehicle shifted automatically to neutral and would not let me switch to drive. I just recently purchased this car (less than two weeks). Based on what i see online and all the complaints on here , this is a known issue. However when i contacted my local Acura they acted as if they never heard of this issue and they want to diagnose my car at my expense. The mileage on my vehicle is between 31,000 and 32,000. I purchased this vehicle to accommodate my newborn granddaughter. Now, I don't feel like its the safe vehicle its advertised to be. This is a very dangerous thing that is happening, how many complaints need to be submitted before the manufacturer is held accountable.

The contact's relative owns a 2020 Acura MDX. The contact stated while driving approximately 25-30 MPH, the check engine warning light started flashing, and the vehicle stalled and lost electrical function. The contact stated that the vehicle was only able to be locked manually, and the windows failed to roll up as intended. The driver was able to pull over to the side of the road. The vehicle failed to restart and was in the process of being towed. The dealer was notified of the failure and informed the contact that the earliest availability for a diagnostic test was in 7 days. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 65,000.

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.

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.

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 NHTSA 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.

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 NHTSA 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.

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.