How to Check for Cooling System Leaks in a Lincoln Navigator

To keep your Lincoln Navigator running in optimum condition, you should perform routine maintenance checks, like inspecting it for cooling system leaks. If the cooling system malfunctions due to a lack of coolant, it can irreparably damage the engine. Checking for these leaks requires no in-depth knowledge of auto mechanics.

Instructions

1

Move the Lincoln Navigator from its usual parking place and examine the area underneath for any signs of a cooling system leak. Because most coolant is green, orange, blue or red in color, it's relatively easy to spot a leak. However, if you don't find any sign of coolant on the ground, there is still the possibility of a leak. The engine heat can evaporate leaked coolant before it reaches the ground.

2

Open the hood, get a flashlight and inspect the radiator for potential leaks. Look for fresh coolant, corrosion or discoloration, all indicators of leaking coolant. Also, check the underside of the radiator, as it often sustains damage from rocks and road debris during the normal course of operation.

3

Inspect the hoses that connect the radiator to the engine and the engine to the heater core. The heater core is behind the engine and up near the windshield. Examine the hoses for bulging, cracking or splitting. Then, check where each hose connects to a part of the cooling system, to make sure the connection hasn't come loose due to engine vibration.

4

Examine the water pump and gasket seal for any fresh coolant, discoloration or corrosion. The water pump on the Lincoln Navigator is behind the engine fan. The gasket seal secures the attachment between the water pump and engine block.

5

Remove the radiator cap and add fresh coolant to the radiator until it's almost overflowing. Touch the radiator prior to opening it, to make sure it's cool. Twist the cap one full turn, step away, wait a minute or two and remove the cap completely.

6

Start the engine of the Lincoln Navigator with the heater set to high. Let it run for about 15 minutes. Switch off the engine and check the water pump, gasket seal, radiator and the hoses for leaks one more time. If there is still no sign of leakage, it's most likely an internal cooling system leak and you should take the Lincoln Navigator to a cooling system specialist for further diagnostics.