2016 Acura MDX

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, NHTSA 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 NHTSA.gov.

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.NHTSA 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 NHTSA.gov.

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)2016–2020 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.  NHTSA 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.

The contact owns a 2016 Acura MDX. The contact stated that while driving at an undisclosed speed, several unknown warning lights illuminated. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The dealer was not made aware of the failure. The manufacturer was not made aware of the failure. The failure mileage was approximately 133,000.

NHTSA ID

11755328

Incident

Jun 16, 2026

Mileage

133,000 mi

I received a letter from Acura about a safety recall on the subframe. My car has been making a creaking noise and so I called the number on the letter. The guy gave me the number to Acura, Brookfield WI. I called and talked to someone there today, I think his name was John. I told him I wanted my car checked for the recall issue and I am worried about the noise. He said a subframe won't cause squeaking and I would have to pay $200 for them to look at it. I said I would call back in fall as the letter states but Im still wanting this issue fixed now.

NHTSA ID

11754628

Incident

Aug 3, 2026

The contact called on behalf of the owner of a 2016 Acura MDX. The contact stated that the owner reported an abnormal knocking sound coming from the engine while starting the vehicle. No warning light was illuminated. The vehicle was towed to the independent mechanic, where the timing belt tensioner was replaced; however, the failure persisted. The mechanic disassembled the oil filter and discovered metal shavings inside the filter. The mechanic related the failure to NHTSA Action Number: PE25008 (Engine). The manufacturer was notified of the failure; however, no assistance was provided because the VIN was not included in NHTSA Campaign Number: 23V751000 (Engine and Engine Cooling). The vehicle was not repaired. The failure mileage was approximately 60,000.

NHTSA ID

11754481

Incident

Jul 3, 2026

Mileage

60,000 mi

The contact owns a 2016 Acura MDX. The contact stated that while the vehicle was parked and attempting to open the trunk, the contact became aware that the inner driver’s side taillight was inoperable. The contact associated the failure with NHTSA Campaign Number: 19V256000 (Exterior Lighting); however, the VIN was not included. The vehicle was taken to an independent mechanic. The independent mechanic stated that the taillight needed to be replaced. The vehicle was not repaired. The dealer was not contacted. The manufacturer was not made aware of the failure. The failure mileage was approximately 149,000.

NHTSA ID

11753988

Incident

Jul 25, 2026

Mileage

149,000 mi

Catastrophic Engine failure. Engine shook, then loss power. Multiple lights went off. Repair shop found metal shavings in the oil pan. Later diagnosed by specialist with cam/rocker engine issue. Recommended action was engine replacement.

NHTSA ID

11751144

Incident

Jul 10, 2026

I just got back home from Walmart, went in my house to get a few things and head to my camper. I had to get one last thing ,so I started to drive over town I noticed a plastic burning smell ,I thought someone was burning trash, so I keep going ,the smell got worse,so I stopped and was going to check what it was and smoke started coming out of the vents,so I turned around drove car home,as I was pulling into my drive ,I noticed the wiring harness fell from behind glove box ,on fire on the floor. We got car in driveway and got out,tried to extinguish the fire but couldn't, so grab everything out of the car,and the car became totally engulfed in flames,the car was totally gone from this electrical short.

NHTSA ID

11750455

Incident

Jul 2, 2026

Engine began knocking, brass colored shaving in drained oil due to bearing damage. This vin is not covered by the recall scope

NHTSA ID

11749666

Incident

Jul 1, 2026

I am filing a safety and compliance complaint regarding execution of Federal Recall Campaign #26V365 by Valley Stream Acura and sales fraud by Paragon Acura. I purchased this 2016 Acura MDX from Paragon Acura on May 29, 2026. I have driven it only 550 miles, placing it strictly within the statutory New York State 60-Day Used Car Lemon Law Warranty window. A certified 6-page independent ASE forensic report documents that Valley Stream Acura bolted the federal recall brackets directly onto severely cracked rear control arms and rusted struts without disclosure. Furthermore, Paragon Acura forced a brand-new front control arm link onto a deeply pitted, scaling, and structurally compromised front steering knuckle to mask pre-sale defects, signing a false NYS highway safety certification. The vehicle was released to me with a bone-dry, empty engine cooling loop, creating an immediate fire hazard. Acura Corporate (Case #16437213) refuses to issue a corrective directive, willfully leaving a non-compliant vehicle on public roads.

NHTSA ID

11749008

Incident

Jun 25, 2026

Owner Notification Letter - Under certain circumstances, after coming to a stop and the idle stop feature engaging, the vehicle may not automatically restart. Acura is providing a product update with a new PGM-FI software update to fix this issue.

Service Bulletin - An uneven sealing surface allows moisture to enter the inner taillight(s), causing one or both of the inner taillights not to work.

Dealer Message - Acura is also implementing an additional (1) twenty-four (24) month period for 2015 model year Acura TLX vehicles, commencing at the expiration of the 10-year warranty extension period for each vehicle, and (2) eighteen (18) month period for 2016 model year Acura TLX/MDX vehicles, commencing at the expiration of the 10-year warranty extension period for each vehicle, for valve adjustment and starter replacement related to this condition under warranty.

Service Bulletin - An uneven sealing surface allows moisture to enter the inner taillight(s), causing one or both of the inner taillights not to work.

Service Bulletin - An uneven sealing surface allows moisture to enter the inner taillight(s), causing one or both of the inner taillights not to work.

Service Bulletin - Under certain circumstances, after coming to a stop and engaging idle stop the vehicle may not restart automatically due to excessive cylinder pressure and/or low cranking torque. Typically, the client can immediately restart the vehicle by selecting Park and pressing the ENGINE START/STOP button.