The 1998 Ford Taurus was available in three trim packages: LX, SE and SHO. The base model Taurus LX was equipped with a 3.0-liter V-6 engine that produced 145 horsepower and 180 foot-pounds of torque. The spark plugs on the front of the base model Taurus are somewhat simple to access. The rear plugs, or right-hand side plugs, are more difficult to get to, requiring the removal of body paneling and wiper parts.
Raise the hood on the Taurus. Disconnect the negative battery cable from the battery, using a ratchet and socket. Lift the cap from the lower end of the passenger wiper arm, using a flat-head screwdriver if needed. Remove the passenger wiper arm hold-down nut, using a ratchet, socket and extension. Remove the wiper arm by raising the arm off the windshield, then pulling up on the entire assembly.
Remove the passenger cowl screen fasteners with a screwdriver. Remove the cowl screen. Remove the cowl upper panel from beneath the screen in the same manner. This will give you access to the rear of the engine.
Remove a single spark plug wire from one of the plugs, using spark plug boot pliers. Do not pull the wire itself, or you will damage the ends of the wire inside the boot. Inspect the boot end for excess white or black powder deposits. Check the entire wire for cracks or wear in the sheathing. If either deposits or cracks exist, replace the spark plug wires along with the plugs.
Remove the spark plug from the engine, using a spark plug socket, ratchet and extension if needed. Turn the plug counterclockwise with your ratchet to release it from the engine. Once the spark plug is sufficiently loose, you can remove the ratchet and turn the socket or extension with your fingers for quicker removal.
Set the gap on the new spark plug between 0.042 and 0.046 inches, using a spark plug gap tool or feeler gauge set. Do not gap platinum or higher-grade spark plugs. If you have platinum plugs that are the wrong gap specification, take them back to your parts vendor and request the proper plug.
Insert the new spark plug into the spark plug socket. Install the plug into the engine and turn it snug with your fingers, using the socket or extension. This will prevent cross threading of the spark plug in the engine. Tighten the spark plug to between 80 and 184 inch-pounds, using a torque wrench, adapter, socket and extension if needed. Install the spark plug wire into the plug by pushing the boot until it clicks and locks onto the plug.
Repeat steps 3 through 6 to replace the remainder of the spark plugs. Install the negative battery cable onto the battery and tighten it snug with your ratchet and socket.
Install the cowl upper piece and fasten it with your screwdriver. Install the wiper cowl screen and push the fasteners in with the handle of the screwdriver. Install the wiper arm onto the wiper arm pivot, so that the arm faces horizontally across the windshield. Tighten the wiper arm mounting nut to between 22 and 29 foot-pounds, using a 1/2-inch-drive torque wrench and socket, with an extension if needed.
