While stopped at a stop light the auto restart feature engaged and shut the engine off. When the light turned green and I released the brake pedal the engine did not restart and the battery warning light illuminated. As cars were honking I activated my hazards, had to place the car in park and shut off/restart the vehicle. Luckily it restarted and I was able to proceed home. It activated again while stopped to get mail at mailbox and restarted with no issue. Mileage is 42668. Recall 23-001 PGMfi performed 8/2023. Battery replaced 12/2024.
2020 Acura MDX engine problems
104 complaints (46% of all complaints for this car). Typical mileage when it fails: 54,651.
- owner complaints
- 104
- of this car's complaints
- 46%
- typical mileage
- 54,651
- crashes
- 0
- recalls
- 1
Which part fails
Owners did not name a specific part.
At what mileage
Complaints by mileage at the time of the problem.
0k-25k
25k-50k
50k-75k
75k-100k
100k-125k
125k-150k
150k-175k
175k-200k
200k+
Acura MDX engine problems in other years
Specific symptoms reported on the 2020 Acura MDX engine
Phrases found in the owners' own descriptions, so one complaint can mention several symptoms.
Stalling 33Knocking 17Engine failure 12Loss of power 12Check engine light 11
Related recalls
Engine and engine cooling: engine: hard parts internal/mechanical
- What is wrong
- Honda (American Honda Motor Co.) is recalling certain 2015-2020 Acura TLX, 2016-2020 Acura MDX, 2016 and 2018-2019 Pilot, 2017 and 2019 Ridgeline, and 2018-2019 Odyssey vehicles. Due to a manufacturing error, the connecting rod bearing in the engine may wear and seize, damaging the engine.
- Risk
- A damaged engine may run improperly or stall while driving, increasing the risk of a fire, crash, or injury.
- Remedy
- Dealers will inspect and repair, or replace the engine as necessary, free of charge. Owner letters were mailed March 28, 2024. 2016-2017 Acura MDX owner letters were mailed November 1, 2024. 2016-2020 Acura MDX owner letters are expected to be mailed in mid-December 2024. Honda began mailing owner notification letters as of March 18, 2024. 2015-2016 Acura owner letters are expected to be mailed mid-December 2024, 2018 Acura TLX owner letters are expected to be mailed the end of March/early April 2024, 2019 Acura TLX owner letters are expected to be mailed mid-May 2024, 2020 Acura TLX owner letters are expected to be mailed mid-June 2024, and 2016-2020 Acura MDX owner letters are expected to be mailed January 27, 2025. Owners may contact Honda customer service at 1‑888‑234‑2138. Honda's numbers for these recalls are XG1 and GG0.
Recall number 23V751000 · Recall details
Related investigations
Engine failure
The Office of Defects Investigation (ODI) has received 414 reports of connecting rod bearing failures in the 3.5L V6 engine used in the following vehicles: Model Years (MY) 2018-2020 Acura TLX, MY2016-2020 Acura MDX, MY2016-2020 Honda Pilot, MY2018-2020 Honda Odyssey, and MY2017-2019 Honda Ridgeline. The subject engine failures were analyzed as part of a Recall Query (RQ24013). It was determined that these engine failures are outside the scope of Honda Recall 23V‑751. Further, evidence gathered in conjunction with RQ24013 does not suggest this failure is caused by the same crankshaft manufacturing defect that is addressed by Honda in Recall 23V‑751. Based on analysis of data from RQ24013, the federal safety agency has closed that investigation. The significant number of reports of engine failure in vehicles outside the scope of RQ24013 presents a potential safety risk that warrants further investigation. ODI is opening this Preliminary Evaluation (PE) to further evaluate the scope and severity of the potential problem and to fully assess the potential safety-related issues. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to
PE25008
No Restart After Auto Start/Stop Engages
On June 3, 2022, the Office of Defects Investigation (ODI) opened Preliminary Evaluation PE22005 after the agency received VOQs and several field reports concerning the Auto Idle Stop (AIS) feature on 2016-2019MY Honda Pilot vehicles. The complaints allege that the engine fails to restart on its own from a complete stop at a traffic light or road intersection with the AIS function engaged. The subject vehicles are equipped with a 3.5L engine with a 9-speed automatic transmission. On January 6, 2023, Honda released service bulletins 23-008 and 23-009. These service bulletins address the failure to restart issue in the 2016-2019MY Honda Pilot vehicles, as well as the 2015-2020 Acura TLX, 2016-2020 Acura MDX, 2019-2022 Honda Passport, and 2020-2023 Honda Ridgeline vehicles. The repair outlined in the service bulletins is a two-stage countermeasure to remedy the issue. The first stage is a Programmed Fuel Injection (“PGM-FI”) software update. The second stage is only deployed if the software update fails to remedy the issue. The second stage, depending on the model and model year, consists of replacement of the starter assembly, starter relays, and a valve adjustment. Additionally, Honda extended the warranty coverage to 10 years with unlimited mileage for vehicles requiring the second stage component replacement. ODI continues to receive complaints of the AIS failure to restart, with many complainants alleging the campaign countermeasures had been completed.the federal safety agency has reviewed Honda's Information Request Letter responses involving warranty claims, lawsuits, and consumer complaints in addition to ODI's own data. This Engineering Analysis is being opened to further consider the potential safety defect, including gathering additional data regarding Honda’s service campaign efficacy. ODI is additionally expanding the scope to encompass all vehicles addressed in Honda’s service bulletins 23-008 and 23-009 as well as newer model year vehicles, which are substantially similar to the vehicles covered by the service campaign. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to
EA25004
Engine failure
On November 8, 2024, the Office of Defects Investigation (ODI) opened Recall Query RQ24013 to assess the scope of Honda recall 23V‑751 after receiving complaints that alleged connecting rod bearing failures in vehicles that were not within the scope of recall 23V‑751. In November 2023, Honda recalled 248,999 various Model Year (MY)2016â2020 Honda and Acura vehicles equipped with the 3.5L V6 engine. Honda recalled these vehicles due to a crankshaft manufacturing defect that caused premature connecting rod bearing wear and engine seizure. While the out-of-scope failures involved in these complaints appear to have a very similar failure mechanism as the recalled engines, a thorough analysis of all available data from Honda has not indicated that the same manufacturing defect exists in the out-of-scope engines as the engines recalled by 23V‑751. Based on this analysis ODI has determined that Honda has properly defined the scope of recall 23V‑751. Consequently, ODI will close this RQ investigation. the federal safety agency will continue to investigate these complaints of engine failure as part of a new Preliminary Evaluation Investigation (PE25008). The Agency reserves the right to take additional action if warranted by new circumstances.
RQ24013
What 2020 Acura MDX owners say
Most recent owner complaints, unedited.
My 2020 Acura MDX fails to restart after the Auto Idle Stop system shuts off the engine at stops. The vehicle stalls and will not restart in active traffic, including busy intersections and high-speed roads. This began about three years ago and now happens every day, leaving my family stranded in live traffic lanes at risk of a collision. On [XXX], the engine shut off and would not restart in the middle of the [XXX], with traffic moving around me at about 40 mph. Capitol Acura in San Jose diagnosed a failing starter motor and ordered a replacement under repair order [XXX]. The part has been on backorder since, with no delivery date. I escalated to American Honda / Acura Client Relations on October 13, 2026 (case [XXX]). On [XXX], Acura replied only that it is "still reviewing" my request. No loaner or alternate vehicle has been provided, and no repair timeline has been given. I am concerned this is a defect affecting other MDX owners: a starter that fails under frequent Auto Idle Stop cycling, combined with a parts shortage that leaves unsafe vehicles on the road. I request that the federal safety agency review this issue for a possible investigation or recall. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
The contact owns a 2020 Acura MDX. The contact stated that the vehicle was previously repaired under Technical Service Bulletins: 22-009, 22-024, and 23-002; however, the failure persisted following the repairs. The contact stated that while stopped at an intersection, the engine failed to restart after the Auto Start/Stop feature engaged, and the transmission independently shifted to Neutral (N). The contact shifted the transmission to Park (P) and pressed the Engine Start/Stop button to restart the vehicle. The vehicle was taken to the dealer, where it was determined that the starter required replacement. The dealer requested that the manufacturer replace the starter; however, the request was denied. The contact associated the failure with the federal safety agency Action Number: EA25004 (Engine and Engine Cooling). The failure mileage was 70,357.
Car is not staying on during traffic. Afraid to go in highway now.
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 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.
The contact owns a 2020 Acura MDX. The contact stated that while operating the vehicle, the oil light illuminated. The contact stated that after restarting the vehicle, while driving, the vehicle failed to properly accelerate, with a ticking and knocking sound coming from the engine compartment. The vehicle was later towed to the local dealer to be diagnosed and metal shavings from the engine bearings were found in the engine oil. The contact was informed that the engine needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was offered. The contact was informed that the VIN was not included in the federal safety agency Campaign Number: 23V751000 (ENGINE AND ENGINE COOLING). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 85,000.
Engine seized multiple times. Completely broken now. Online it says many people have these problems.
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.
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 the federal safety agency 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.
Questions about the 2020 Acura MDX engine
Does the 2020 Acura MDX have engine problems?
Owners have filed 104 complaints about the engine of the 2020 Acura MDX, 46% of all its complaints, more than any other problem.
At what mileage do 2020 Acura MDX engine problems start?
The typical (median) mileage in owner complaints is 54,651 miles.
Was there a recall on the 2020 Acura MDX engine?
Yes, 1 recall: 23V751000. Check your VIN to see if your car still needs the free repair.
What year does the Acura MDX have bad engine?
The Acura MDX model years with the most engine complaints are 2016 (173 complaints), 2020 (104 complaints) and 2017 (97 complaints).
Other 2020 Acura MDX problems
Electrical 42Driver assistance 38Fuel system 23Transmission 21Brakes 15Acceleration 14Lights 7Airbags 5Steering 4Visibility 4Seats 3Suspension 3Tires 2Wheels 2Body 1Seat belts 1
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