2021 Acura RDX problems

Filed Oct 29, 2026 · Engine · AZ

My 2021 Acura RDX A-Spec AWD had approximately 89,000 miles when this incident occurred on [October 23rd] on I-10 in Tempe Arizona]. My wife was driving when the vehicle displayed emissions and brake-system warnings, lost power and slowed unexpectedly. She was unable to restart it at that time. The unexpected loss of power in freeway traffic created a safety concern. I was subsequently able to drive the vehicle to the dealership. Acura of Tempe inspected the vehicle. Its written diagnosis reported an “ENGINE TEMP HIGH” warning, misfires after the vehicle had been sitting, an empty coolant reservoir and low radiator coolant. The dealer diagnosed a head gasket leaking coolant into a cylinder and recommended head gasket replacement, with further inspection for cylinder-head damage. The dealer provided an approximately $4,000 repair estimate, with potential additional costs depending on the cylinder-head findings. I am reporting the unexpected loss of power and the diagnosed coolant intrusion as a potential safety defect. I can provide the dealership’s written diagnosis and estimate. Approximate speed at the time: 65 MPH. Crash, injuries or fire: [None. Current repair status: [not repaired ].

Filed Oct 21, 2026 · Seat belts · 42,000 miles · FL

The contact owns a 2021 Acura RDX. The contact stated that the front passenger’s side seat belt retractor failed to retract as needed. The vehicle was taken to a dealer and was inspected and repaired. The failure mileage was 42,000

Filed Oct 12, 2026 · Visibility · FL

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

Filed Oct 7, 2026 · Engine, Fuel system · TX

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.

Filed Oct 1, 2026 · MA

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

Filed Sep 25, 2026 · Engine · IL

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.

Filed Sep 23, 2026 · Engine · MA

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

Filed Aug 22, 2026 · Brakes, Electrical · NY · crash

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.

Filed Aug 20, 2026 · Fuel system · UT

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.

Filed Jul 30, 2026 · Transmission · IL

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.