Does 2003 Toyota Sienna have a timing chain or belt and if so, when it needs to be replaced?
As of my knowledge, the 2003 Sienna has 3.0L V6 engine with a timing belt; of course, you can double check with your Toyota dealer. According to Toyota website: “If your vehicle is a 1999 model year or newer and is equipped with a timing belt, you should replace it every 90,000 miles or six years, whichever comes first”.
