2007 Buick LaCrosse Owner's Manual - Page 365

Checking Coolant The coolant recovery tank is located in the engine compartment toward the rear of the engine on the passenger's side of the vehicle. See Engine Compartment Overview on page 350 for more information on location. 3.8L V6 Engine shown, 3.6L V6 Engine similar The vehicle must be on a level surface when checking the coolant level. When the engine is cold, the coolant level should be at the cold fill line or a little higher. The cold fill line is near the bottom of the recovery tank and has an arrow pointing down at it. 365