Spark plug wire check and replacement

1. The spark plug wires should be checked at the recommended intervals and whenever new spark plugs are installed in the engine. V6 engines have spark plug wires that go from the spark plugs all the way to an ignition coil assembly. V8 engines have individual coils for each cylinder and short spark plug wires from each coil to the corresponding spark plug.

2. Begin this procedure by making a visual check of the spark plug wires while the engine is running. In a darkened garage (make sure there is adequate ventilation) start the engine and observe each plug wire. Be careful not to come into contact with any moving engine parts. If there is a break in the wire, you will see arcing or a small spark at the damaged area. If arcing is noticed, make a note to obtain new wires.

3. Disconnect the plug wire from one spark plug (with the engine off). To do this, grab the rubber boot, twist slightly and pull the wire free. Do not pull on the wire itself, only on the rubber boot. A boot-pulling tool is helpful.

4. Check inside the boot for corrosion, which will look like a white crusty powder. Push the wire and boot back onto the end of the spark plug. It should be a tight fit on the plug. If it isn’t, remove the wire and use a pair of pliers to carefully crimp the metal connector inside the boot until it fits securely on the end of the spark plug.

5. Using a clean rag, wipe the entire length of the wire to remove any built-up dirt and grease. Once the wire is clean, check for holes, burned areas, cracks and other damage. Don’t bend the wire excessively or the conductor inside might break.

6. Disconnect the wire from the coil. Pull the wire straight out of the coil. Pull only on the rubber boot during removal (see illustration). Check for corrosion and a tight fit in the same manner as the spark plug end. Reattach the wire to the ignition coil.

32.6 Use a spark plug boot pulling tool to remove each end of a spark plug wire — never pull on the wire itself

Chevrolet Silverado  _ Use a spark plug boot pulling tool to remove each end of a spark plug wire - never pull on the wire itself

7. Check the remaining spark plug wires one at a time, making sure they are securely fastened at both ends when the check is complete.

8. If new spark plug wires are required,

purchase a new set for your specific engine model. Wire sets are available pre-cut, with the rubber boots already installed. Remove and replace the wires one at a time to avoid mix-ups in the firing order. The wire routing is extremely important, so be sure to note exactly how each wire is situated before removing it. On V6 engines, release the ignition wire loom clamps to exchange the wires, then snap the clamps back in place on the new wires.

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