How Do I Set the Spark Plug & Wires on a 2004 Chevy Tahoe?

The 2004 Chevrolet Tahoe base model was equipped with a 4.8-liter V-8. A 5.3-liter standard fuel injected V-8, and a 5.3-liter flex-fuel injected V-8 were optional engines. The engines were equipped with two types of ignition coil packs and wire sets. A Delphi system will have a round coil pack and white foil wrapping on the wires. A Melco system will have a square ignition coil pack and white foil wrapping on the wires. These ignition cables and coil packs are not interchangeable.

Instructions

1

Open the hood on the Tahoe. Remove the negative battery cable from the battery, using a ratchet and socket.

2

Remove one of the spark plug boots from a spark plug. Twist the boot 1/2-turn counterclockwise, then pull the boot off the spark plug. Use spark plug boot pliers to remove the boot if needed. Do not pull on the wire lest you separate the wire from the boot.

3

Remove the spark plug from the engine, using a 3/8-inch-drive ratchet, spark plug socket and extension. Turn the plug counterclockwise to remove it from the engine. Remove the spark plug wire from the ignition coil pack by twisting it and pulling the boot by hand. Use spark plug boot pliers if needed. Discard the old wire and the old spark plug.

4

Measure the distance between the metal ground arc on the spark plug and the center diode pin, using a spark plug gap tool or feeler gauges. Set the spark plug gap to 0.040 inches, using the spark plug gap tool to expand the gap size. Increase the gap slowly and do not pry on the center diode or you will ruin the new spark plug. If the gap is already too large, use a bench vise or channel locks to lightly compress the ground arc toward the diode.

5

Install the new spark plug into your spark plug socket. Detach your extension and socket from the ratchet. Install the new spark plug by hand to ensure proper threading of the plug into the engine. Tighten the spark plug to 11 foot-pounds, using a 1/2-inch-drive torque wrench, extension, adapter and spark plug socket. Install the new spark plug wire onto the spark plug and the ignition coil pack. Push the plug until it clicks and locks into place. Wiggle the boot sideways gently to test your connections, and fix any loose wire connections.

6

Repeat steps 2 through 5 to complete the rest of the spark plug and wire replacements. Install the negative battery cable onto the battery when all the plugs and wires have been replaced. Tighten the cable snug using a ratchet and socket.