2020 Acura MDX Problems

What owners report

Owners of this model year most often describe the engine shutting down or failing to restart around the idle-stop feature, and a smaller but notable group reports internal engine noise followed by bearing failure. The idle-stop complaints appear from very low mileage onward, while the knocking and seizure reports cluster at higher mileage, often past 45,000 miles. A separate set of complaints centers on the windshield camera that drives the driver-assist systems failing and taking several features offline at once.

1. 1
   Electrical system

   Engine shuts off or won't restart at idle stop

   • 96 complaints (42%)
   • median 26,000 mi at 4.4 yrs old (17 state mileage)
   • 2 mention a crash, fire or injury
   • filed 2022–2026

   Owners describe stopping at a light or stop sign with the idle-stop feature engaged, then finding the engine will not restart when the brake is released, sometimes leaving the vehicle in neutral and requiring a shift to Park and a manual restart. Some say the dashboard flickers or goes blank during the event, and a few report the shutdown happening while driving rather than only at a stop. Complaints note that battery replacement, starter replacement, and software updates were tried, and in several cases the symptom returned afterward. Reported from very low mileage, commonly between roughly 6,000 and 55,000 miles, and often in stop-and-go driving.

   9 related service bulletins

   What to check: Ask the seller whether the idle-stop software updates and any extended-coverage repair were applied, and confirm the battery and starter history. During a test drive, let the idle-stop engage at a stop and verify the engine restarts cleanly.

   2 excerpts from owner complaints in NHTSA records

   “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. …”

   NHTSA complaint #11632790, filed 2024-12, 54,651 miles

   “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. …”

   NHTSA complaint #11756994, filed 2026-08
2. 2
   Engine

   Engine knocking and seizure (rod bearing)

   • 29 complaints (13%)
   • median 65,128 mi at 5.7 yrs old (11 state mileage)
   • filed 2024–2026

   Complaints describe a ticking or knocking sound from the engine, often first noticed at idle or on cold starts, that can become loud before the engine loses power and stalls. Several owners report dealers diagnosing connecting rod bearing wear or a seized engine and quoting an engine or short-block replacement. Some complain that the recall repair part was unavailable for an extended period, and others say their vehicle was not covered by the recall despite a similar diagnosis. Mostly reported between roughly 45,000 and 105,000 miles, with several around 55,000 to 70,000 miles.

   Recall 23V751000

   What to check: Listen for ticking or knocking at idle and on a cold start, and have a pre-purchase inspection check for metallic debris in the oil. Ask whether the engine recall was completed and request any engine repair records.

   2 excerpts from owner complaints in NHTSA records

   “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? …”

   NHTSA complaint #11666192, filed 2025-06, 101,841 miles

   “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.”

   NHTSA complaint #11637711, filed 2025-01
3. 3
   Fuel system

   Stalling and hesitation while driving

   Mentioned in 6 of 60 sampled complaints

   Owners describe the engine hesitating or cutting out at various speeds with no warning light, sometimes restarting immediately and sometimes needing a tow. Complaints mention that the low-pressure fuel pump recall repair part was not yet available, and some report the stalling continued after recall work. Others describe the vehicle being hard to start, and one report ties the concern to a fuel rail pressure code found during dealer diagnosis. Reported from roughly 12,000 to 70,000 miles, with several around 25,000 to 60,000 miles.

   Recall 23V858000Recall 21V2150005 related service bulletins

   What to check: Ask whether the fuel pump recall was performed and request the repair invoice. Note any hesitation or long cranking during the test drive and check for stored check-engine codes.

   2 excerpts from owner complaints in NHTSA records

   “The contact owns a 2020 Acura MDX. The contact stated that while driving in Comfort Mode at approximately 40 MPH and attempting to accelerate to change lanes, the vehicle stalled for several minutes before accelerating. There were no warning lights illuminated. The vehicle hesitated to start intermittently, and the failure was more frequent over time. The vehicle was taken to the dealer, who diagnosed that the battery had failed. …”

   NHTSA complaint #11653622, filed 2025-04, 48,193 miles

   “The contact owns a 2020 Acura MDX. The contact received notification of NHTSA Campaign Numbers: 23V858000 (Fuel System, Gasoline) contact 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. The contact stated while driving at an undisclosed speed, the vehicle stalled with no warning light illuminated. The vehicle was able to restart; however, the failure recurred. …”

   NHTSA complaint #11607227, filed 2024-08, 136,000 miles
4. 4
   Forward collision avoidance

   Driver-assist camera failure disables safety features

   • 35 complaints (15%)
   • median 19,725 mi at 2.7 yrs old (3 state mileage, few)
   • 1 mention a crash, fire or injury
   • owner-quoted repair $2,000 (median of 11 quotes)
   • filed 2021–2026

   Owners report multiple warnings appearing at once — lane keeping, collision mitigation, road departure, adaptive cruise control, and auto high beam — after the windshield-mounted camera stops working. Some describe the collision mitigation braking activating with no vehicle ahead, or reacting to traffic in an adjacent lane. Complaints say dealers diagnosed an internal camera failure and quoted a replacement plus recalibration, with one owner noting the camera was not covered after a windshield replacement. Reported from very low mileage up to about 45,000 miles, sometimes after windshield work.

   What to check: Start the car and confirm no driver-assist warning messages appear, and check whether the windshield is original or has been replaced. Ask whether the front camera has been replaced or recalibrated.

   2 excerpts from owner complaints in NHTSA records

   “I am reporting a failure of the multipurpose front windshield camera in my vehicle, which resulted in the loss of multiple safety systems including Lane Keeping Assist System (LKAS), Road Departure Mitigation (RDM), Adaptive Cruise Control (ACC), Auto High-Beam, and Collision Mitigation Braking System (CMBS). These features are critical to safe driving, and their sudden deactivation poses a serious safety risk to both the driver and others on the road. This issue required costly repairs. …”

   NHTSA complaint #11664198, filed 2025-06

   “I drove my car in the morning and parked it in the lot for about an hour. After I came back and started my car, the following multiple safety systems displayed on my dashboard at the same time: - Lane Keeping Assist Problem - Collision Mitigation System Problem - Road Departure Mitigation System Problem - Auto High Beam Problem - Adaptive Cruise Control Problem When I took it to the dealership on the same day to diagnose this, they came back and said it was an internal failure with the camera and quoted me around $2200 to replace and …”

   NHTSA complaint #11704183, filed 2025-12

Buying note. Check the recall status for the engine bearing, fuel pump, and tailgate lighting campaigns, and verify whether the idle-stop software updates were applied. A cold-start listen for engine knock and a test of the driver-assist warnings are worth doing before purchase, and service records for battery and starter replacements help show how the idle-stop concern was handled.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.