Is there a cabin air filter in a 2004 Chevy Silverado?
The 4.3L, 4.8L, 5.3L, do not have a cabin air filter despite it being listened as an option in the GM parts catalog. via
When should you replace idler pulley?
An idler pulley is expected to wear over time, and eventually the pulley will fail. Replacement intervals for idler pulleys vary, but are usually within the 50,000 to 100,000 mile range. Replacement often coincides with expected serpentine/accessory belt replacement periods. via