Replacing spark plugs 2002 Mercury Mountaineer

Mercury Mountaineer

Replacing spark plugs and new ones wont go back in. Old ones were corroded but came out.


First make certain your new plugs are the exact same as the old ones. See if you can install one of the old plugs and remove it. DO NOT cross thread the spark plug hole. But try to install the new ones again if they are the same as the old ones. If you are still having an issue return tot he store with both sets of plugs and ask for some that match your old ones.

Stripped out spark plug holes

If you are unable to install the old ones or new ones because there is no longer any thread then you will need to repair it. This will require cutting new threads and installing a new insert. Here is the Plug Hole Repair kit you will need to do it yourself.

Spark Plugs

Removal and Installation

  1. Remove the spark plug wires from the spark plugs.
  2. NOTE: Use compressed air to remove any foreign material in the spark plug well before removing the spark plugs. NOTE: If an original spark plug is reused, make sure it is installed in the same cylinder it was taken from. New spark plugs can be used in any cylinder. Remove the spark plugs.
  1. Inspect the spark plugs.
  2. Using a suitable spark plug gap tool, check and adjust the spark plug gap.
spark plug gap
  1. To install, reverse the removal procedure.