2011 Chevrolet Silverado 1500 Regular Cab Owner's Manual - Page 426

10-20 Vehicle Care When to Inspect the Engine Air Cleaner/Filter Inspect the air cleaner/filter at the scheduled maintenance intervals and replace it at the first oil change after each 80 000 km (50,000 mi) interval. See Scheduled Maintenance on page 11‑2 for more information. If driving on dusty/dirty conditions, inspect the filter at each engine oil change. Engine Air Cleaner/Filter If the vehicle has a diesel engine, see "Pickup Models" under "Engine Air Cleaner/Filter" in the Duramax® Diesel Supplement for the correct inspection and replacement procedures. See Engine Compartment Overview on page 10‑6 for the location of the engine air cleaner/filter. How to Inspect the Engine Air Cleaner/Filter To inspect the air cleaner/filter, remove the engine air cleaner/filter from the vehicle by following Steps 1 through 6. When the engine air cleaner/filter is removed, lightly shake it to release loose dust and dirt. If the engine air cleaner/filter remains covered with dirt, a new filter is required. Never use compressed air to clean the filter.