2002 GMC Envoy Owner's Manual - Page 293

If No Steam Is Coming From Your Engine CAUTION: Steam from an overheated engine can burn you badly, even if you just open the hood. Stay away from the engine if you see or hear steam coming from it. Just turn it off and get everyone away from the vehicle until it cools down. Wait until there is no sign of steam or coolant before you open the hood. If you keep driving when your engine is overheated, the liquids in it can catch fire. You or others could be badly burned. Stop your engine if it overheats, and get out of the vehicle until the engine is cool. If you get an engine overheat warning but see or hear no steam, the problem may not be too serious. Sometimes the engine can get a little too hot when you: D D D D Climb a long hill on a hot day. Stop after high-speed driving. Idle for long periods in traffic. Tow a trailer. See "Driving on Grades" in the Index. If you get the overheat warning with no sign of steam, try this for a minute or so: 1. If your air conditioner is on, turn it off. 2. Turn on your heater to full hot at the highest fan speed and open the window as necessary. 3. If you're in a traffic jam, shift to NEUTRAL (N); otherwise, shift to the highest gear while driving -- DRIVE (D) or THIRD (3). NOTICE: If your engine catches fire because you keep driving with no coolant, your vehicle can be badly damaged. The costly repairs would not be covered by your warranty. 5-9