2021 Acura RDX engine problems
20 owner complaints filed with NHTSA name the engine on the 2021 Acura RDX — 18% of all complaints for this model year.
What owners report
“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…”
filed Jul 17, 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…”
filed Jul 16, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
Service Bulletin - Oil leak at the cam chain tensioner inspection cover due to and insufficient sealant adhesion on the inspection cover.
B25-049 · Service Bulletin/Repair Instructions · issued Sep 17, 2025
Engine problems in other RDX years
| Year | Reports | Share |
|---|---|---|
| 2025 RDX | 1 | 3% |
| 2023 RDX | 4 | 19% |
| 2022 RDX | 1 | 3% |
| 2020 RDX | 51 | 15% |
| 2019 RDX | 89 | 21% |
| 2018 RDX | 10 | 13% |
| 2017 RDX | 11 | 15% |
| 2016 RDX | 7 | 18% |
| 2015 RDX | 3 | 1% |
| 2014 RDX | 2 | 1% |
| 2013 RDX | 2 | 1% |
| 2010 RDX | 2 | 9% |
Other reported problem areas on the 2021 Acura RDX
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.