2010 GMC Terrain Owner's Manual - Page 289

Vehicle Care 9-15 { WARNING Operating the engine with the air cleaner/filter off can cause you or others to be burned. The air cleaner not only cleans the air; it helps to stop flames if the engine backfires. Use caution when working on the engine and do not drive with the air cleaner/filter off. Notice: If the air cleaner/filter is off, dirt can easily get into the engine, which could damage it. Always have the air cleaner/filter in place when you are driving. Cooling System 3.0L V6 Engine 2.4L L4 Engine A. Engine Cooling Fan B. Engine Coolant Surge Tank and Pressure Cap A. Engine Cooling Fans B. Engine Coolant Surge Tank and Pressure Cap { WARNING An electric engine cooling fan under the hood can start up even when the engine is not running and can cause injury. Keep hands, clothing, and tools away from any underhood electric fan.