The 2004 Toyota Sienna is a midsize minivan built for families who need comfortable seating, easy daily drivability, and strong long-term value. For 2004, Sienna launched as an all-new second-generation model with a larger body, more power, and improved refinement compared to the prior design. It slots in as a practical alternative to sportier SUVs, focusing on passenger space, sliding-door convenience, and road-trip comfort. Buyers often consider it for its reputation for durability, but it’s still important to understand 2004 Toyota Sienna problems and common wear points as the miles add up.

1) 3.3L V6 power: Most 2004 Sienna models use a 3.3-liter V6 (3MZ-FE) producing about 230 hp, paired with a 5-speed automatic transmission for smooth, confident highway merging. 2) Seating and space: Available 7- or 8-passenger seating (depending on trim and configuration) with a roomy cabin and a family-friendly layout that makes car seats and third-row access easier. 3) Available AWD: Certain trims offered all-wheel drive, a major plus for drivers in snow or heavy rain who want minivan practicality without moving to an SUV. 4) Dual sliding doors: Sliding doors improve tight-parking usability, and higher trims may include power operation for added convenience. 5) Strong safety and comfort upgrades: This generation brought a more modern interior, improved ride quality, and available features like rear HVAC controls and upgraded audio, making it a competitive choice in the early-2000s minivan segment.

When people search “2004 Toyota Sienna reliability,” the model often scores well overall, but age and mileage matter. Here are several 2004 Toyota Sienna common issues reported by owners and technicians: 1) Automatic transmission concerns (especially on high-mileage vans): Some owners report harsh shifting, delayed engagement, or slipping that can show up around 120,000–180,000 miles, particularly if fluid changes were neglected. Not every van experiences this, but a careful test drive and fluid inspection is important. 2) Power sliding door problems: Power door cables, motors, or sensors can wear out over time, leading to doors that stop mid-track, reverse unexpectedly, or require manual operation. This is a common convenience issue on older minivans and often appears after years of heavy family use. 3) Engine oil leaks and seepage: On higher-mileage 3.3L V6 examples, valve cover gasket seepage and general oil leaks can develop, sometimes noticeable around 100,000–150,000 miles. Leaks are often manageable but should be addressed to avoid oil loss and mess on belts or mounts. 4) Suspension and steering wear: Struts, sway bar links, and control arm bushings can wear with age, creating clunks over bumps, uneven tire wear, or vague steering feel. This tends to show up as the vehicle passes 120,000 miles, especially in rough-road climates.