Every 5 years
Under the hood on the opposite side of the coolant.
You can purchase a coolant flush kit from your local auto parts store for less than $10. It comes with directions.
You don't have to but it is a good opportunity to flush the system.
Toyota Long Life coolant. Pricey. Any brand name ethylene-glycol based coolant, mixed 50/50 would be OK.
The coolant capacity for a 2001 Toyota Sienna is approximately 9.0 quarts (or about 8.5 liters) when using the standard cooling system. This includes the radiator and engine block, but it's always a good idea to check the owner's manual for specific details and recommendations based on your vehicle's configuration.
*shrugs* come on why cant you figure that out "just ask your local 2001 Toyota sienna speaker dealer"
Clean the reservoir and flush the cooling system.
2001 Honda Odyssey, I just had this done and it cost $97.00 Hudson, MA
Should really flush your system every year to prevent any rusting or fouling, but at the very least every 2 years.
The 2001 Toyota Sienna has a V6 engine.
The 2001 Toyota Sienna has 24 valves.
The 2001 Toyota Sienna has a 4-speed automatic.