1996 GMC Sonoma Owner's Manual - Page 200

A Heater and radiatorhoses, and otherengine parts, can be very hot. Don't touch them. If you do, you can be burned. Don't run theengine if there is-a leak. If you run the engine, itcould lose all coolant. That could cause an engine fire, and you could be burned. Get any leak fixed before you drive thevehicle. The coolant level should be at the ADD mark. If it isn't, you may have a leak in the radiator hoses, heater hoses, radiator, water pump or somewhere else in the cooling system. 1 NOTICE: Engine damage from running your engine by without coolant isn't covered your warranty. If there seems to be n o leak, start the engine again. See if the fan speed increases when idle speed is doubled by pushing the accelerator pedal down. If it doesn't, your vehicle needs service. Turn off the engine. 5-14