General Motors advises replacing the engine-air filter in your 2007 Buick Lacrosse every 50,000 miles. The replacement interval, as well as the procedure, is the same whether your Lacrosse is equipped with the 3.6L or 3.8L engine. If you drive in dusty or dirty conditions, GM recommends inspecting the filter at each oil change, and replacing it if necessary. A dirty air filter can decrease engine performance and acceleration by 6 to 11 percent, according to the EPA.
Turn the engine off. Open the hood and approach the driver-side engine compartment. Locate the air-filter compartment. It’s a large-black box, mounted horizontally.