How to Replace Spark Plugs in a Mercury Cougar

The Mercury Cougar is available in two different engine sizes: the 2.0 liter and the 2.5 liter. In a Cougar with a 2.0 liter engine, change the spark plugs every 60,000 miles. The 2.5 liter engines require the spark plugs to be changed every 100,000 miles.

Instructions

1

Gain access to the spark plug wires after making sure the engine is cool. Use a screwdriver to remove the engine cover if the engine is equipped with one. Most newer models have these covers.

2

Loosen the bolts on the spark plug cover if the engine does not have spark plugs running along the sides or in plain view. The cover is located across the top of the engine with six to eight bolts holding it down. If the Cougar engine is a 2.5 liter engine, unscrew the ignition coil assembly and remove the water pump pulley cover.

3

Remove one spark plug wire at a time. Hold the wire by its boot (the end of the wire). Turn the boot to unlock it from the spark plug. Finish replacing each spark plug before removing the next wire.

4

Use the spark plug socket, extension and wrench to unscrew and remove the old spark plug. On newer Cougar models, the spark plugs are as far as 6 inches inside the cylinder well.

5

Rub anti-seize lubricant onto the threads of the new spark plug.

6

Lower the spark plug into the well with the socket and extension. Manually thread the spark plug into the well.

7

Test the tension of the plug and adjust it as needed. The tension ranges depending on the year and manufacturer of the plug. The specified tension is printed on the spark plug's package.

8

Replace the spark plug wire and then repeat the entire process with the remaining spark plugs. Once the process is complete, replace any components that were removed to access the spark plugs.