2018 Toyota Sienna power train problems
19 owner complaints filed with NHTSA name the power train on the 2018 Toyota Sienna — 27% of all complaints for this model year.
What owners report
“Transmission whining above 20mph. Toyota customer care program [XXX] states my vehicle falls within timeframe but dealer and corporate will not honor repairs INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)”
filed Sep 17, 2026
“Vehicle: 2018 Toyota Sienna XLE AWD, VIN [XXX], approximately 112,000 miles. Component: Power Train / Automatic Transmission (UA80F 8-speed). The vehicle has developed a pronounced whining noise from the transmission that rises with road speed, accompanied by harsh/rough shifting. A Toyota dealer…”
filed Jul 14, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Power Train problems in other Sienna years
| Year | Reports | Share |
|---|---|---|
| 2022 Sienna | 2 | 2% |
| 2021 Sienna | 8 | 5% |
| 2020 Sienna | 8 | 21% |
| 2019 Sienna | 7 | 16% |
| 2017 Sienna | 36 | 24% |
| 2016 Sienna | 3 | 4% |
| 2015 Sienna | 12 | 5% |
| 2014 Sienna | 7 | 4% |
| 2013 Sienna | 14 | 8% |
| 2012 Sienna | 17 | 7% |
| 2011 Sienna | 30 | 5% |
| 2010 Sienna | 17 | 10% |
Other reported problem areas on the 2018 Toyota Sienna
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.