2009 Mercury Mariner Owner's Manual - Page 282

Maintenance and Specifications How fail-safe cooling works If the engine begins to overheat: • The engine coolant temperature gauge will move to the red (hot) area. indicator light will illuminate. • The service engine soon If the engine reaches a preset over-temperature condition, the engine will automatically switch to alternating cylinder operation. Each disabled cylinder acts as an air pump and cools the engine. When this occurs the vehicle will still operate. However: • The engine power will be limited. • The air conditioning system will be disabled. Continued operation will increase the engine temperature and the engine will completely shut down, causing steering and braking effort to increase. Once the engine temperature cools, the engine can be re-started. Take your vehicle to an authorized dealer as soon as possible to minimize engine damage. When fail-safe mode is activated You have limited engine power when in the fail-safe mode, so drive the vehicle with caution. The vehicle will not be able to maintain high-speed operation and the engine will run rough. Remember that the engine is capable of completely shutting down automatically to prevent engine damage, therefore: 1. Pull off the road as soon as safely possible and turn off the engine. 2. Arrange for the vehicle to be taken to an authorized dealer. 3. If this is not possible, wait a short period for the engine to cool. 4. Check the coolant level and replenish if low. WARNING: Never remove the coolant reservoir cap while the engine is running or hot. 5. Re-start the engine and take your vehicle to an authorized dealer. Driving the vehicle without repairing the engine problem increases the chance of engine damage. Take your vehicle to an authorized dealer as soon as possible. FUEL FILTER Your vehicle is equipped with a lifetime fuel filter that is integrated with the fuel tank. Regular maintenance or replacement is not needed. 282 2009 Mariner (mrn) Owners Guide, 2nd Printing USA (fus)