If your engine has a timing belt, (more that half of the engines do) be sure to replace when your manufacturer says to. It’s usually anywhere from 60 – 100k miles. A broken timing belt can cause huge engine damage by bending valves and breaking pistons. If you don’t know whether your engine has a chain or a belt, call your dealer and find out if it does, and when to change it. The timing belt is buried inside the engine and it are as hard to check for wear as they are to change. Just do this, don’t chance it. Also, be sure to have the shop replace any of the other items connected to be belt since you are in there and the labor charge is less. This way you won’t have to spend the money to go inside the engine for another 60-90k miles.