The 2024 Sienna is still very new to the market, but early patterns mirror issues seen in the 2021-2023 hybrid models. The hybrid powertrain is generally solid, but transmission oil cooler failures and engine oil consumption problems are emerging as the primary concerns.
Transmission Oil Cooler Failure
Occasional · high severity
Typical onset: 40,000-80,000 mi
Symptoms: Transmission fluid leaking into coolant or vice versa (milky fluid in either system), Transmission slipping or harsh shifts, Engine overheating, Check engine light with transmission temperature codes
Fix: Replace transmission oil cooler, flush both cooling system and transmission. Requires partial transmission disassembly and coolant system purge. 4-6 hours labor plus parts.
Estimated cost: $1,200-2,000
Excessive Oil Consumption / Piston Ring Failure
Occasional · high severity
Typical onset: 30,000-70,000 mi
Symptoms: Burning a quart of oil every 1,000-2,000 miles, Blue smoke from exhaust on startup or acceleration, Fouled spark plugs, Low oil warning light despite recent oil change
Fix: Toyota has a pattern of oil consumption issues on some A25A-FXS engines. Repair requires engine teardown to replace piston rings or full short block replacement in severe cases. 18-24 hours labor for short block swap.
Estimated cost: $5,000-8,500
Transmission Mount Failure
Common · medium severity
Typical onset: 50,000-90,000 mi
Symptoms: Clunking noise when shifting from park to drive or reverse, Excessive vibration at idle, Visible sagging or torn rubber on mount inspection
Fix: Replace failed transmission mount. The hybrid CVT and electric motor assembly is heavy, causing accelerated wear. 2-3 hours labor.
Estimated cost: $400-700
Fuel System Contamination / Fuel Filter Clogging
Rare · medium severity
Symptoms: Hard starting or extended cranking, Loss of power under acceleration, Check engine light with fuel pressure or lean codes, Rough idle
Fix: Related to fuel tank manufacturing debris or poor fuel quality. Requires fuel filter replacement and sometimes fuel system cleaning or tank drop. 2-4 hours depending on contamination extent.
Estimated cost: $300-900
Hybrid System Inverter Cooling Issues
Rare · high severity
Typical onset: 60,000-100,000 mi
Symptoms: Hybrid system warning light, Reduced power mode, Intermittent loss of electric motor assist, Overheating warnings in hot weather or under load
Fix: Inverter cooling pump or coolant passages can fail. Requires diagnosis with Toyota Techstream scanner, replacement of cooling pump or inverter assembly. 3-6 hours labor.
Estimated cost: $1,500-3,500
Owner tips
Check oil level every 1,000 miles religiously—early oil consumption detection can prevent catastrophic engine damage
Use Toyota Type IV or equivalent CVT fluid only—aftermarket fluids accelerate transmission oil cooler degradation
Have hybrid system health check performed at 50,000 miles to catch inverter cooling issues early
Inspect transmission mounts annually after 40,000 miles—cheap preventive replacement beats tow bills
Wait another year for the oil consumption and transmission cooler issues to shake out—the 2025+ models should have these addressed under warranty campaigns.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: AGM battery required for hybrid system; auxiliary 12V battery located in rear cargo area
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Every control module on the 2021-2026 Toyota Sienna — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
⚠️ Mileage programming required; VIN registration mandatory; digital cluster on higher trims
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
Vantage Mobility, LLC (VM) is recalling certain 2021-2026 Honda Odyssey, 2021-2025 Chrysler Pacifica, and Toyota Sienna vehicles equipped with QRT-Deluxe and QRT-Max wheelchair restraints. The retractors may not lock, preventing the wheelchair from being properly secured.
Consequence: An unsecured wheelchair can move during transit, increasing the risk of injury.
Remedy: Dealers will inspect and replace the retractors, free of charge. Owner notification letters was mailed January 27, 2026. Owners may contact Vantage Mobility customer service at 1-800-488-9082.
Performance
Horsepower
245hp
0–60 mph
8.1sec
Quarter mile
16.2sec
Top speed
115mph
Fuel economy (EPA)
City
36mpg
Highway
36mpg
Combined
36mpg
Fuel
Regular Gasoline
Capability & size
Towing capacity
3,500lb
Payload
1,405lb
Curb weight
4,675lb
Seating
8seats
EPA class
Minivan - 2WD
Wiper blades
Fourth generation (XL40). All trims use same wiper sizes.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2024 Toyota Sienna 2.5L I4 Hybrid and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years.