1998 GMC Safari Owner's Manual - Page 236

If No Steam Is Coming From Your Engine If you get the overheat waming but see or hear no -steam,the problem may-notbe too serious. Sometimes the engine can get little too hot when you: a Climb a long hill a hot day. on Stop after high-speed driving. Idle for long periods in traffic. Tow a trailer. See "Driving on Grades" in the Index. If you no longer have the overheat warning, you can drive.Just to be safe, drive slower about for 10 minutes. If the warning doesn't come back on, you can drive normally. If the warning continues, pull over, stop, and park your vehicle right away. If there's still no signof steam, push the accelerator until the engine speed about twice as fast as normal is idle speed. Bring the engine speed back to normal idle speed after two or three minutes. Now see warning if the stops. But then, if you have the warning,turn o still f the engine and everyone out o the vehicle until it get f cools down. You may decide not to lift the hood but to get service help right away. .If you get the overheat warning with sign of steam, no try this for a minute orso: 1. Turn off your air conditioner. 2. Turn on your heater full hot at the highest fan to speed and open the window necessary. as 3. If you're in a traffic jam, shift toNEUTRAL (N); otherwise, shift to the highest gear while driving -- DRIVE (D). 5-14