2015 Toyota Sienna engine problems
15 owner complaints filed with NHTSA name the engine on the 2015 Toyota Sienna — 7% of all complaints for this model year.
What owners report
“I am submitting this complaint to request that the National Highway Traffic Safety Administration (NHTSA) document and evaluate what may be a broader defect affecting certain Toyota Sienna vehicles and determine whether it presents a potential safety-related defect trend. My 2015 Toyota Sienna was…”
filed Jul 17, 2026
“i am having repeated issue with Toyota sienna engine 1. Engine oil leaks through timing chain cover 2. Engine coolant leak Engine oil leak keep repating even I fixed earlier and leaks again due poor engine design same issue fixed on Nov/22/20 - 59k”
filed Feb 6, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Engine problems in other Sienna years
| Year | Reports | Share |
|---|---|---|
| 2022 Sienna | 5 | 4% |
| 2021 Sienna | 8 | 5% |
| 2020 Sienna | 6 | 17% |
| 2019 Sienna | 4 | 9% |
| 2018 Sienna | 5 | 7% |
| 2017 Sienna | 15 | 10% |
| 2016 Sienna | 4 | 5% |
| 2014 Sienna | 11 | 7% |
| 2013 Sienna | 7 | 4% |
| 2012 Sienna | 9 | 4% |
| 2011 Sienna | 23 | 4% |
| 2010 Sienna | 5 | 3% |
Other reported problem areas on the 2015 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.