At what mileage should the timing belt on a 2001 Chevy Silverado 1500 be changed.?

The recommended mileage for a timing belt replacement on a 2001 Chevy Silverado 1500 depends on the engine. There's no single answer. You MUST check your owner's manual. It will specify the recommended interval for your specific engine (4.3L, 4.8L, 5.3L, or 6.0L are common in that year).

However, a general guideline often cited is around 100,000 miles, but this is just a *rough estimate*. Some sources might suggest slightly earlier or later, depending on driving conditions. Ignoring the owner's manual could lead to catastrophic engine failure. The cost of a replacement is far less than the cost of engine repair.