2021 Acura RDX Complaints

VISIBILITY/WIPER — Filed 10/11/2026

Rear window shattered spontaneously twice. 9/12/24 & 10/11/26

ENGINE,FUEL/PROPULSION SYSTEM — Filed 09/21/2026

2021 Acura RDX has cold start, uses coolant and will stumble, limp mode approaching 2000 RPM. Vehicle will flash check engine light and then will go away when vehicle is restarted. Using search criteria noted TSB issued for same make model and year with an extended warranty being offered through TSB, 10 year 150,000 miles. Vehicle has 103,000 miles. Dealer is stating no TSB for this VIN, however the number one issue noted through internet searches and this database.

UNKNOWN OR OTHER — Filed 10/01/2026

Acura Sunnyside in New Hampshire denied to repair my recall on my 2021 Acura RDX.

ENGINE — Filed 09/20/2026

Engine was replaced 12/13/25 due to cracked cylinder head causing oil to leak into exhaust and fill cylinder 2 and 3. 09/21/26 new engine replacement done in December 25, has now blown cylinder head gasket seal in under 12,000 Miles. Causing coolant to leak into cylinders 2 and 3.

ENGINE — Filed 09/01/2025

Head Gasket blown known problem with Honda and Acura 2.0T I didn’t know of this issue until it occurred to Loi Me in 2025 My Acura dealership told me it’s a huge problem with the Acura RDXand it should be a warranty extension similar to the warranty extension for other Honda products done in August 27, 2026 I was lucky and my head gasket didn’t blow while I was driving I’m also concerned that it’s gonna happen again I’m not sure if the problem was resolved with the new head gasket or it’s a stomach problem with the motor that has not been addressed yet

ELECTRICAL SYSTEM,UNKNOWN OR OTHER,SERVICE BRAKES — Filed 08/19/2026

Two low-speed sudden unintended acceleration events while parking a 2021 Acura RDX. Incident 1 (July 2026): While parking at low speed, the car unexpectedly surged forward. Flew up the curb and hit a restaurant window, causing massive undercarriage damage. Active braking did not help and seemed to make acceleration worse. It only stopped when it wanted to. Incident 2 (August 2026): Two weeks after getting the car back from repairs, under identical low-speed parking conditions, a second sudden acceleration event occurred. Slamming on the brakes did nothing. It stopped after scraping a car wash vacuum pole, destroying the entire passenger side. Prior to these, the car exhibited erratic safety software behavior, including multiple phantom braking incidents where it slammed on its brakes violently with no obstacles present. I bought the car Certified Pre-Owned two years ago. The dealership repaired a known "popping sound" from the panoramic sunroof frame three times. This required extensive cabin/pillar teardown work, which may have disturbed internal wiring harnesses or grounding points linked to the electronic throttle control system. In both events, it felt like an uncontrolled amusement park ride—the engine loudly revving and taking over with zero driver control. I initially assumed pedal confusion during the first crash, but since it happened again under identical circumstances, there is clearly a systemic electronic/software defect in the Throttle Actuator or Powertrain Control Module. The vehicle is at an insurance network body shop awaiting forensic evaluation of the throttle system, pedal sensors, and a Bosch EDR black box download.

FUEL/PROPULSION SYSTEM — Filed 07/06/2026

Fuel Pump is having to be replaced. I have had issues accelerating and my car also stalled once on the freeway. It put me in a dangerous situation and I almost got in an accident because my speed quickly decreased. The same part was recalled on the previous year’s model.

POWER TRAIN — Filed 07/09/2026

I own an Acura RDX that experienced a sudden failure of the transfer case. Prior to the failure, there was little or no warning that a major drivetrain component was about to fail. When the transfer case failed, the vehicle lost its normal all-wheel-drive operation and required expensive repairs. I believe this is a safety defect because the transfer case is a critical drivetrain component. A sudden failure can reduce traction and vehicle control, especially when driving at highway speeds or on wet, snowy, or icy roads. Drivers may not expect the loss of power to the rear wheels, which could increase the risk of skidding, loss of stability, or being unable to safely accelerate into traffic or avoid a hazard. In addition, there are numerous reports from other Acura RDX owners describing similar transfer case failures, suggesting this may not be an isolated incident but a recurring problem. A critical drivetrain component should not fail prematurely under normal use without adequate warning. I believe this issue warrants investigation because it has the potential to affect vehicle safety and place drivers and passengers at unnecessary risk.

POWER TRAIN — Filed 07/09/2026

I own an Acura RDX that experienced a sudden failure of the transfer case. Prior to the failure, there was little or no warning that a major drivetrain component was about to fail. When the transfer case failed, the vehicle lost its normal all-wheel-drive operation and required expensive repairs. I believe this is a safety defect because the transfer case is a critical drivetrain component. A sudden failure can reduce traction and vehicle control, especially when driving at highway speeds or on wet, snowy, or icy roads. Drivers may not expect the loss of power to the rear wheels, which could increase the risk of skidding, loss of stability, or being unable to safely accelerate into traffic or avoid a hazard. In addition, there are numerous reports from other Acura RDX owners describing similar transfer case failures, suggesting this may not be an isolated incident but a recurring problem. A critical drivetrain component should not fail prematurely under normal use without adequate warning. I believe this issue warrants investigation because it has the potential to affect vehicle safety and place drivers and passengers at unnecessary risk.

POWER TRAIN — Filed 07/09/2026

I own an Acura RDX that experienced a sudden failure of the transfer case. Prior to the failure, there was little or no warning that a major drivetrain component was about to fail. When the transfer case failed, the vehicle lost its normal all-wheel-drive operation and required expensive repairs. I believe this is a safety defect because the transfer case is a critical drivetrain component. A sudden failure can reduce traction and vehicle control, especially when driving at highway speeds or on wet, snowy, or icy roads. Drivers may not expect the loss of power to the rear wheels, which could increase the risk of skidding, loss of stability, or being unable to safely accelerate into traffic or avoid a hazard. In addition, there are numerous reports from other Acura RDX owners describing similar transfer case failures, suggesting this may not be an isolated incident but a recurring problem. A critical drivetrain component should not fail prematurely under normal use without adequate warning. I believe this issue warrants investigation because it has the potential to affect vehicle safety and place drivers and passengers at unnecessary risk.

POWER TRAIN — Filed 07/09/2026

I own an Acura RDX that experienced a sudden failure of the transfer case. Prior to the failure, there was little or no warning that a major drivetrain component was about to fail. When the transfer case failed, the vehicle lost its normal all-wheel-drive operation and required expensive repairs. I believe this is a safety defect because the transfer case is a critical drivetrain component. A sudden failure can reduce traction and vehicle control, especially when driving at highway speeds or on wet, snowy, or icy roads. Drivers may not expect the loss of power to the rear wheels, which could increase the risk of skidding, loss of stability, or being unable to safely accelerate into traffic or avoid a hazard. In addition, there are numerous reports from other Acura RDX owners describing similar transfer case failures, suggesting this may not be an isolated incident but a recurring problem. A critical drivetrain component should not fail prematurely under normal use without adequate warning. I believe this issue warrants investigation because it has the potential to affect vehicle safety and place drivers and passengers at unnecessary risk.

UNKNOWN OR OTHER — Filed 07/18/2026

While driving only at 35 miles per hour down the XXX in [XXX] my panoramic sunroof suddenly bursts. A loud pop sound. This would have popped all over my body if I didn’t have cover up. This is an extreme problem as someone can die from this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ENGINE — Filed 07/13/2026

Vehicle lost all coolant and could be smelled. Vehicle was towed to dealership before it could overheat. Diagnosed with a cracked cylinder head at 88,000 miles. Vehicle has never been modified, tracked, nor has it ever overheated. All service has been performed on time and at Acura dealership since I purchased the vehicle brand new. Vehicle is still at dealership. I've researched and found many other owners experiencing the same problem with the crack occurring in the exact same spot on the cylinder head.

VEHICLE SPEED CONTROL,SERVICE BRAKES,ENGINE — Filed 07/15/2026

On or about XXX, my 2021 Acura RDX, with approximately 121,078 miles, suddenly displayed multiple dashboard warning lights and system-failure messages while I was driving. These included the check-engine light, Road Departure Mitigation System Problem, steering, stability-control, braking-assistance and other driver-assistance warnings. Earlier, the tire-pressure monitoring system had also indicated a malfunction even though the tire pressures were correct. The vehicle initially continued to drive and the conventional brakes appeared to function normally. However, it then began hesitating when I attempted to accelerate. The vehicle would eventually gain speed, but the initial hesitation created a serious safety concern when pulling into traffic or attempting to accelerate. The check-engine light remained solid while the vehicle was stopped but flashed whenever I began driving and accelerating again. No crash, fire or injury occurred. The vehicle had undergone a full diagnostic inspection approximately two weeks earlier, and I was informed that everything checked out properly. There were no known drivability problems before this incident, and the vehicle has been maintained according to the manufacturer’s recommended service schedule. The vehicle was subsequently inspected by Elite Acura, an authorized Acura dealership in [XXX]. The dealership confirmed a head-gasket failure and a problem with the rear differential left-side actuator. The dealer recommended replacing the head gasket, four spark plugs, coolant, oil and filter, as well as replacing the rear differential left-side actuator and changing the differential fluid. The estimated head-gasket repair was $5,391.46, and the estimated rear differential actuator and fluid service was $813.85. The dealer also recommended rear brake pads and rotors. The head-gasket and rear differential actuator problems were confirmed by the authorized Acura dealership. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

POWER TRAIN — Filed 11/01/2025

A transmission fluid leak has been identified emanating from the passenger side output shaft seal, located between the transmission and the transfer case. This issue pertains to 2019–2023 Acura RDX and TLX models equipped with SH-AWD, specifically at the interface where the transmission connects to the front transfer case, which is responsible for power distribution to the rear wheels. It appears that the fitment tolerances at this connection point are problematic, suggesting a potential engineering deficiency that warrants a manufacturer-funded resolution..

ELECTRICAL SYSTEM — Filed 10/29/2025

The contact owns a 2021 Acura RDX. The contact stated that while at a complete stop at a stop sign or traffic light, the engine auto stop-start system was inoperable upon depression of the brake pedal. The vehicle was taken to the dealer, but the failure could not be duplicated. The dealer initially suggested that the battery might require replacement. However, another dealer determined that the battery was functioning properly and exhibited no defects upon inspection. The manufacturer was not notified of the failure. The failure mileage was unavailable.

ELECTRICAL SYSTEM,EXTERIOR LIGHTING — Filed 10/04/2021

The Auto High-Beam system activates the high beams inappropriately during operation. The system triggers the high beams directly into the eyes of oncoming traffic and activates during early dusk conditions. The sudden, intense illumination blinds oncoming drivers. This creates an immediate glare hazard and significantly increases the risk of a head-on collision. I reported this specific failure to the authorized dealership on three separate occasions, engaging three distinct service advisors during the active warranty period. The service department omitted these complaints from the formal repair orders. The first advisor stated the system was functioning normally. The second advisor stated the technicians completed an inspection and verified the system as fully operational. The third advisor acknowledged experiencing the exact same malfunction on their personal vehicle and instructed me to manually disable the safety feature. The system fails silently, displaying zero warning lamps or error messages prior to or during the malfunctions. The attached service invoices document a severe, underlying instability within the vehicle's electrical and Advanced Driver Assistance Systems (ADAS) network, culminating in a complete VSA modulator replacement. These records establish a confirmed administrative pattern of the dealership dismissing intermittent safety faults, officially logging statements such as "unable to verify issue" and "no problem found" on subsequent visits. This evidentiary paper trail substantiates the dealership's systemic suppression of my specific, repeated verbal reports regarding the Auto High-Beam safety hazard. The vehicle and the Auto High-Beam system remain available for inspection upon request.

UNKNOWN OR OTHER — Filed 03/20/2026

On March 20th, my husband and I went out to dinner with three friends. We arrived around 6:50 PM and left our car with the valet. When we returned later that evening to pick up the vehicle, a valet employee approached us and asked us to walk with him to the car. The police were already present at the scene. The employee explained that when he entered the vehicle on the driver’s side to return it to us, he closed the door and immediately heard the sound of glass shattering. When we reached the car, we saw that the entire rear window had been shattered. The police later reviewed the surveillance footage and confirmed that the incident occurred exactly as described by the valet employee.

VISIBILITY — Filed 02/10/2026

The contact owns a 2021 Acura RDX. While driving at an undisclosed speed, there was an abnormal gunshot sound coming from the vehicle. The vehicle was driven to the residence. The contact inspected the exterior of the vehicle but found no failure. The contact stated that the following day, while driving at an undisclosed speed, the panoramic roof glass shattered, and glass shards fell inside the vehicle. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 56,000.

VISIBILITY/WIPER — Filed 02/24/2026

Got in my vehicle as usual, started the vehicle shortly after I heard cracking thought nothing of it and all of a sudden the rear tailgate window shattered completely.

STRUCTURE,UNKNOWN OR OTHER — Filed 02/09/2026

- Rear window shattered without impact or any signs of stress. - Safety at risk if driving and breakage occurs. In this case I was away from the parked vehicle when the shattering occurred. - There are quite a few reports of this issue online in Facebook Acura owner groups and in published news stories such as this: [XXX] - In my case, it was inspected by the repair company and confirmed to be a common occurrence they are called to repair. - There were no warning lights or any signs of damage or stress to the glass. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ELECTRICAL SYSTEM — Filed 01/01/2024

Infotainment system fails on occasions. Sceen goes completely blank causing distraction while driving. There is currently a recall for this issue for 2019-2020 RDX.

VEHICLE SPEED CONTROL,UNKNOWN OR OTHER,ENGINE — Filed 05/22/2024

Drove into parking lot and as I was pulling into the parking spot next to the building, the vehicle started to surge forward as if I had my foot on the gas instead of the brake. The sudden surge caused the vehicle to plow into a brick building causing about $10K damage to the vehicle and $5K to the building. This was not the first time this sudden surging occurred. It happened at least 3 times previously, and one time since. Fortunately, the other occurrences did not lead to any damages, but just some anxious moments. I took the vehicle to the dealership to get checked out after the last occurrence, but they said they couldn't duplicate it. I thought it might be some sort of "unknown" problem, until I started reading on Facebook and other internet websites of other people having the same scary "surging" engine issues. I believe there's more to it now, and an investigation is warranted.

STRUCTURE,UNKNOWN OR OTHER — Filed 10/29/2023

The panoramic sunroof exploded on our Acura RDX model 2021. Me, my wife and our 3 month old son were returning from dinner, we took the ramp and about to merge on a highway then we heard a loud and sudden explosive noise which scared all of us. Thank God we had the sunroof blind partially closed over the real infant seat, so the glass shatters left some minor cuts on my left forearm and back (glass pieces got between my back and driving seat). Also, the glass pieces did cut the sunroof blind/rolling cloth screen. We are glad that we made home safe and not sure what is the process of getting the issue fixed by the manufacturer and thorough cleaning up of the glass remains/dust. Please advise.

SERVICE BRAKES,ENGINE — Filed 04/05/2023

While sitting in a long row of stopped vehicles at a traffic light for an extended amount of time due to an accident I had the Automatic Brake Hold feature activated { I did not have to have my foot on the brake while sitting still) as well as the Auto Idle Stop OFF button meaning {the engine shuts down when you come to a stop.} Apparently, the Brake Hold feature timed out with no warning whatsoever and because the vehicle moved forward the Auto Start Stop feature activated at the same time and the vehicle lurched forward rear ending a new expensive SUV in front of me. The impact was hard due to the quick lurch of my vehicle. I have damage to the front of my vehicle and all of the electronic features started flashing including the emission control. The driver advised she was very shaken up and if a pedestrian or bicyclist had been in front of us it could have been very tragic.The vehicle is being towed to A local Acura dealer for evaluation and I have a Case number assigned by Honda with no case manager assigned yet. There were no warning lights/lamps at all prior to the vehicle Brake Hold timing out and further searching through the manual only says it times out after 10 minutes but does not advise what happens when that happens or what warning will be used.