2015 Toyota Sienna Complaints

  • Engine 08/12/2026

    Component Failed & Availability: The engine on my 2015 Toyota Sienna (99,000 miles) catastrophically failed and is completely seized. The vehicle and engine are in my possession and are fully available for physical inspection. Safety Risk: The vehicle shut down completely while in motion, causing an immediate loss of motive power, power steering, and power braking assistance. Had this un-warned seizure occurred at highway speeds rather than a parking lot, the sudden loss of vehicle control would have posed a severe crash hazard. Reproduced/Confirmed: Yes. A certified mechanic removed the serpentine belt, attempted to turn the engine with a lock bar, and confirmed the engine block is completely seized. The local dealership, Fred Haas ToyotaWorld, also confirmed the vehicle does not run. Inspections: The vehicle was inspected by my independent mechanic and the local dealership. However, Toyota Corporate formally refused my request to dispatch a field engineer to inspect the defective...

  • Engine 05/22/2026

    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 diagnosed by an authorized Toyota dealership with an external rear-bank head gasket leak. A head gasket is a critical engine component, and failure can result in coolant loss, engine overheating, reduced engine performance, stalling, or complete vehicle disablement. These conditions may create a safety risk, particularly if they occur while driving in traffic or at highway speeds. An authorized Toyota dealership confirmed the diagnosis and submitted a goodwill assistance request to Toyota. The dealership noted my history as a repeat Toyota customer and recommended that assistance be provided. Toyota denied the goodwill request based on the vehicle's age and mileage. I subsequently appealed th...

  • Tires 07/01/2026

    I have requested urgent warranty evaluation regarding two Kumho Solus TA51a tires installed on my Toyota Sienna (Model: Kumho Solus TA51a, Size: 235/60R17 102H, DOT: 1824) Both front tires are exhibiting abnormal tread chunking and visible surface shredding. The tires are relatively new (purchased about 1-1.5 years ago) and have not been heavily used (only riding this car occassionally, about 5000-7000 miles per year). Our 2 rear tires are Kumho tires of different model, and although older, they are performing fine and do not experience these issues so it seems to be an issue on this particular Solus TA 51a model Kumho tires. Because this is our family vehicle and we transport our children in it regularly, we are very concerned about the safety of continuing to drive on these tires. I also returned to the tire shop that sold and installed the tires. After inspecting them, the owner advised me to contact Kumho for a warranty evaluation, informing me that he received similar complaints...

  • Steering 06/15/2026

    My 2015 Toyota Sienna has “Sticky” steering. When on a curve, like an highway curved ramp, the steering locks in place. I have to pull the steering wheel back to keep the car on track. When it sticks I can literally let go on a curve and it will hold it’s position. Even when driving straight this occurs. The steering wheel will stick in place requiring me to turn it to get the steering wheel to come back to the desired or correct position. I’m seeing that this is a regular problem for Toyota steering across multiple models. Having your steering get stuck in place has the potential to be a very serious safety issue. This may cause an accident and resulting death. The complete repair for this safety issue to the consumer is over $3000.00. This is ridiculous! This is my first Toyota. I think their reliability night be really over rated.

  • Seat Belts, unknown Or Other 05/22/2026

    Rain water leaking into the parked vehicle on the driver and passenger seat belts, potentially weakening the belts and creating odor.

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