Chevrolet suggests you replace the spark plugs in Chevy Silverado engines every 60,000 to 100,000 miles depending on the amount of wear the truck endures. The Chevy Silverado is available in five different models: the Silverado, 1500, 1500 Heavy Duty, 2500 Heavy Duty and 3500. All of these models have different aspects, but the process for replacing the spark plugs is the same.
1. Remove the black, negative battery cable. Allow the engine to cool. Depending on the temperature and climate it may take the engine 30 minutes to 2 hours to cool.
2. Gain access to the spark plug wires that are located on the side of the engine. Lift the plastic cover on the side to access the spark plug wires.
3. Grasp the spark plug wires by the boot of the wire. The wire boot is the cap that connects directly to the Silverado engine. Turn the boot halfway to the right and then halfway to the left to loosen the wire from the plug.
4. Attach the socket to the spark plug. Turn the wrench to the left to unscrew and remove the old spark plug.
5. Clean the inside of the wire boot with the wire brush. Lightly spray the boot and threads of the new spark plug with silicone lubricant.
6. Insert the new spark plug into the engine and manually screw it in place. Use the tension tester tool to find the tension of the spark plug. The appropriate tension level is printed on the spark plug’s packaging. Tighten or loosen the spark plug to achieve the required tension.
7. Replace the spark plug wires. Turn the plug back and forth to lock it in place. Replace the plastic cover back onto the engine and return the battery cable to the battery.