When do you change timing chain on 2001 Toyota Corolla?

According to the factory-recommended maintenance schedule outlined in the owner's manual for the 2001 Toyota Corolla, there is no scheduled maintenance interval for replacing the timing chain. Instead, the timing chain is considered to be a "lifetime" component, meaning that it is designed to last the entire lifespan of the vehicle without requiring replacement.

However, it is still important to be aware that certain factors, such as extremely high mileage, poor maintenance, or extreme wear and tear, can cause the timing chain to stretch, skip, or break, leading to engine damage. If you suspect that your timing chain might be damaged or in need of replacement, it's best to have it inspected by a qualified mechanic to assess its condition and determine if replacement is necessary.