GMC Sierra Owners Manual

Engine Overheating
Vehicle Care / Vehicle Checks / Engine Overheating

If the vehicle has the Duramax Diesel engine, see the Duramax Diesel Supplement for more information.

The vehicle has several indicators to warn of engine overheating.

There is a coolant temperature gauge on the vehicle's instrument panel. See Engine Coolant Temperature Gauge on page 5‑17.

In addition, there are ENGINE OVERHEATED STOP ENGINE, ENGINE OVERHEATED IDLE ENGINE, and ENGINE POWER IS REDUCED messages in the Driver Information Center (DIC) on the instrument panel. See Engine Cooling System Messages on page 5‑44 and Engine Power Messages on page 5‑46.

If the decision is made not to lift the hood when this warning appears, get service help right away. See Roadside Assistance Program (U.S.

and Canada) on page 13‑8 or Roadside Assistance Program (Mexico) on page 13‑10.

If the decision is made to lift the hood, make sure the vehicle is parked on a level surface.

Then check to see if the engine cooling fans are running. If the engine is overheating, both fans should be running. If they are not, do not continue to run the engine and have the vehicle serviced.

Notice: Engine damage from running your engine without coolant is not covered by the vehicle warranty. See Overheated Engine Protection Operating Mode for information on driving to a safe place in an emergency.

Notice: If the engine catches fire while driving with no coolant, the vehicle can be badly damaged.

The costly repairs would not be covered by the vehicle warranty.

See Overheated Engine Protection Operating Mode on page 10‑26 for information on driving to a safe place in an emergency.

If Steam is Coming from the Engine Compartment

WARNING
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. 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 the vehicles engine is overheated, the liquids in it can catch fire. You or others could be badly burned.

Stop the engine if it overheats, and get out of the vehicle until the engine is cool.

See Overheated Engine Protection Operating Mode on page 10‑26 for information on driving to a safe place in an emergency.

If No Steam is Coming from the Engine Compartment

The ENGINE OVERHEATED STOP ENGINE or the ENGINE OVERHEATED IDLE ENGINE message, along with a low coolant condition, can indicate a serious problem.

If there is an engine overheat warning, but no steam is seen or heard, the problem may not be too serious. Sometimes the engine can get a little too hot when the vehicle:
Climbs a long hill on a hot day
Stops after high-speed driving
Idles for long periods in traffic
Tows a trailer; see Trailer Towing on page 9‑84.

If the ENGINE OVERHEATED STOP ENGINE or the ENGINE OVERHEATED IDLE ENGINE message appears with no sign of steam, try this for a minute or so:

1. Turn the air conditioning off.

2. Turn the heater on to the highest temperature and to the highest fan speed. Open the windows as necessary.

3. If stopped in a traffic jam, apply the brake, shift to N (Neutral); otherwise, shift to the highest gear while drivingD (Drive) or 3 (Third).

If the temperature overheat gauge is no longer in the overheat zone or an overheat warning no longer displays, the vehicle can be driven.

Continue to drive the vehicle slowly for about 10 minutes. Keep a safe vehicle distance from the vehicle in front. If the warning does not come back on, continue to drive normally.

If the warning continues, pull over, stop, and park the vehicle right away.

If there is no sign of steam, idle the engine for five minutes while parked. If the warning is still displayed, turn off the engine until it cools down. Also, see Overheated Engine Protection Operating Mode later in this section.


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