The service book recommends changing the timing belt (and I would recomment also changing the water pump along with it, as it will save you time and money) every 90 k miles, or roughly 144 000 km, or 72 months.
I personally exchange them every 150 000 km, on both my 2006 Toyota Avalon XLS and on Lexus ES 330.
90,000 miles
chain
The 3.0 liter V6 engine in a 2001 Toyota Avalon has a timing BELT
The 3.5 liter V6 engine in a 2005 Toyota Avalon has a timing CHAIN
Dealer says it never needs to be replaced.
1997 Avalon has a belt
Belt.
belt
How do you change a timing belt on a 1998 Toyota Tacoma? And what part do I need to buy?
According to the Gates website ( they make timing belts etcetera ) The 3.0 litre V6 engine in a 2000 Toyota Avalon has a timing BELT
Well before you ask that question. The real question is how often do you drive your vehicle and how far you drive.
The 2007 Toyota Sienna V6 has a timing chain. It does not require maintenance.