2008 Chevrolet Impala Owner's Manual - Page 277

If the overheat warning no longer exists, the vehicle can be driven. Just to be safe, drive slower for about 10 minutes. If the warning does not come back on, the vehicle can be driven normally. If the warning continues, and you have not stopped, pull over, stop, and park the vehicle right away. If there is still no sign of steam, idle the engine for three minutes while parked. If the warning is still there, turn off the engine and get everyone out of the vehicle until it cools down. Also, see "Overheated Engine Protection Operating Mode" later in this section. You may decide not to lift the hood but to get service help right away. Overheated Engine Protection Operating Mode This emergency operating mode allows your vehicle to be driven to a safe place in an emergency situation. If an overheated engine condition exists, an overheat protection mode which alternates firing groups of cylinders helps prevent engine damage. In this mode, you will notice a significant loss in power and engine performance. The coolant temperature gage will indicate an overheat condition exists. Driving extended miles (km) and/or towing a trailer in the overheat protection mode should be avoided. Notice: After driving in the overheated engine protection operating mode, to avoid engine damage, allow the engine to cool before attempting any repair. The engine oil will be severely degraded. Repair the cause of coolant loss, change the oil and reset the oil life system. See Engine Oil on page 5-17. 5-31