How to Troubleshoot the Cooling System in a Lincoln Navigator

Pinpoint problems with your cooling system by understanding how it works. Simply stated, coolant collects heat as it passes through the engine and releases heat when it goes in the radiator. Cooling devices mainly circulate antifreeze, contain it or control its temperature. Troubleshoot the cooling system in a Lincoln Navigator by regularly inspecting cooling system devices. Work with a mechanic for these steps that apply to most model years.

Instructions

1

Check your water pump for leaks. The water pump keeps the coolant moving through the engine, radiator and heater core. A faint coolant smell or spots of antifreeze under your Navigator when parked for short periods are signs of a faulty water pump.

2

Inspect hoses for cracks, collapses, leaks or dryness. This includes upper and lower radiator hoses, heater and bypass hoses and manifold coolant hoses. The upper hoses measure about 2-inches wide and carry coolant between the radiator and engine. A damaged hose causes cooling system problems.

3

Look at the coolant level. Low antifreeze results in overheating and other cooling problems. With low levels, add coolant mixture to the expansion tank reservoir. Find the reservoir on the driver's side of the engine next to the brake fluid reservoir. This location applies to the 5.4L 4V V8 engine.

4

Drain your coolant and flush the system when pinpointing cooling problems. Disposing antifreeze properly is as important as draining it because the sweet smell of coolant attracts animals and small children. Ingesting the toxic liquid can be deadly.

5

Examine the radiator cap to see if it is faulty. A damaged cap could show signs of corrosion. Ask a mechanic to use a pressure tester or an adapter to examine the cap's pressure rating and functioning. Promptly replace a defective cap.

6

Clean up the front of your radiator. Dirt, rocks, leaves and other debris suck into the fins of your radiator when driving which causes overheating. Use a soft nylon brush, soapy water and a water hose to clean your radiator front.

7

Test the thermostat to see if it is sticking. One way to identify a stuck thermostat is constant low temperature readings or peaks between high and normal temperatures. Your thermostat, a spring-loaded valve that reacts to coolant temperatures, generally sits inside the housing on the engine side of the upper radiator hose.