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2021 Acura RDX engine problems

24 complaints (20% of all complaints for this car). 2 crashes reported.

owner complaints
24
of this car's complaints
20%
crashes
2
recalls
0

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 RDX engine problems in other years

20072010201520202025

Specific symptoms reported on the 2021 Acura RDX engine

Phrases found in the owners' own descriptions, so one complaint can mention several symptoms.

Check engine light 12Loss of power 12

Related recalls

No recalls on record for this model year.

What 2021 Acura RDX owners say

Most recent owner complaints, unedited.

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 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 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 Jul 17, 2026 · Engine · CA

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.

Filed Jul 16, 2026 · Acceleration, Brakes · NJ

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)

Filed Jun 9, 2025 · Acceleration, Engine · PA · crash

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.

Filed Jun 1, 2025 · Brakes, Engine · NY

I have a 2021 Acura RDX A-spec AW and ever since I had a brakes problem, when applying brakes will not take break promptly kept slipping like going I address this to the dealer numerous time and what they said is that they haven’t had a recall in order to know what really the problem is I think is due to my calipers and probably rotors, but I think is the cut for defect on these 2021 Acura RDX . Also my engine been leaking oil from the top rear side and rear the valve cover this need to be addressed and I have made a complaint to Acura Honda The Corp. and they said they haven’t been a recall for this. Also, I would like someone to look at this matter break And engine problem due to a leak that could cost a fire.

Filed May 9, 2025 · Brakes, Electrical · NY

It was raining and I was sat at a stop light. The brakes started to slip a little no matter how much I pressed then all of a sudden the entire car started shutting down. Engine, Transmission, Power Steering, Lane Keep Assist, Collision warning, all the lights started flashing. The car was put into Limp mode.

Filed Jan 30, 2025 · Driver assistance, Engine · NC

While accelerating off the entrance ramp onto the highway, The engine randomly slows down automatically…the car reduced speed drastically without applying brakes and without cars around me or in front of me.

Questions about the 2021 Acura RDX engine

Does the 2021 Acura RDX have engine problems?

Owners have filed 24 complaints about the engine of the 2021 Acura RDX, 20% of all its complaints, more than any other problem.

At what mileage do 2021 Acura RDX engine problems start?

Not enough complaints include the mileage to tell.

Was there a recall on the 2021 Acura RDX engine?

There is no recall for this problem on this model year.

What year does the Acura RDX have bad engine?

The Acura RDX model years with the most engine complaints are 2019 (92 complaints), 2020 (57 complaints) and 2021 (24 complaints).

Other 2021 Acura RDX problems

Brakes 16Visibility 15Transmission 13Airbags 11Body 10Electrical 10Acceleration 7Driver assistance 7Seats 6Fuel system 5Seat belts 5Lights 2Steering 2Suspension 2Wheels 1

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