Engine Overheating (Diesel Engine Vehicles)

In most situations, the temperature gauge reading should be in the middle position of the needle. Engine temperature may rise during prolonged driving uphill, especially in hot weather. If the coolant temperature gauge needle approaches the red mark on the scale, determine the cause of engine overheating.

If you continue driving the vehicle when the coolant temperature gauge needle is in the red zone, the engine may be seriously damaged and fail.

The engine may overheat for various reasons, such as insufficient coolant or mechanical problems. The coolant temperature gauge needle moving into the red zone may be the only sign of engine overheating. Or you may see steam coming from under the hood. Regardless of the cause of engine overheating, you must take emergency measures.

Steam and spray of boiling coolant escaping from an overheated engine can cause severe burns.

Do not open the hood if steam is coming from under it.

1. Stop the vehicle on the shoulder in a safe place. On a vehicle with a manual transaxle, shift the transmission into Neutral. On a vehicle with an automatic transaxle, move the selector lever to the P (Park) position. Apply the parking brake. Turn off the air conditioner/climate control system and other auxiliary equipment. Turn on the hazard warning flashers.

2. Turn off the engine if steam is coming from under the hood or hot coolant is leaking.

3. If there is no steam or hot coolant leaking from the cooling system, leave the engine running at idle and monitor the coolant temperature gauge. If the overheating was caused by increased engine load (for example, climbing a prolonged steep grade on a hot day with the air conditioner on), the engine temperature should begin to drop almost immediately. After the engine temperature has returned to normal and the gauge needle is back in the middle of the scale, you may continue driving.

4. If the coolant temperature gauge needle remains in the red zone, turn off the engine.

5. Wait until the steam emission or fluid leak stops, then open the hood.

6. Check for visible signs of coolant leakage, such as cracks in the radiator hose.

Since all engine and cooling system components are hot, be careful not to get burned. If a leak is found, correct the problem before continuing to drive (refer to "Towing a Disabled Vehicle" on page 562).

7. If you do not find a coolant leak, check the coolant level in the coolant reserve tank. Add coolant if the level is below the MIN mark.

8. If it is necessary to add coolant, open the reserve tank cap. Before doing so, turn the ignition on and check the coolant temperature gauge reading. Do not open the reserve tank until the coolant temperature drops to normal or the gauge needle leaves the red zone of the scale. The cooling system must not make gurgling noises.

Do not remove the radiator filler cap while the engine is still hot. Doing so may cause severe scalding from hot coolant or steam.

Do not remove the radiator cap until the engine and radiator have cooled.

9. When removing the reservoir cap, use a cloth or gloves to protect your hands. Loosen the reservoir cap by turning it 1/8 turn counterclockwise. Then wait some time to allow the pressure in the system to drop. After that, remove the cap by turning it counterclockwise.

10. Start the engine and turn the temperature control to the maximum heat position. If the vehicle is equipped with automatic climate control, press the AUTO mode and set the maximum temperature "". Add coolant to the reserve tank up to the MAX mark. If recommended coolant is not available, you may add clean water to the radiator. At the first opportunity, completely drain the cooling system of coolant diluted with water and refill it with the recommended coolant.

11. Install the reserve tank cap and tighten it securely. Start the engine and monitor the coolant temperature gauge.

If the needle rises again into the red zone, the engine requires repair (see "Towing a Disabled Vehicle" on page 562). 12. If the engine temperature has returned to normal, check the coolant level in the reserve tank. If necessary, add coolant to the tank up to the MAX mark.

Install the reserve tank cap and tighten it securely.