2012 Chevrolet Express 2500 V8-4.8LFACTORY OEM SERVICE PROCEDURE

Spark Plug: Service and Repair




Spark Plug Replacement

Removal Procedure

1. Remove the spark plug wires. Refer to Spark Plug Wire Replacement Service and Repair.

Factory service manual diagram




2. Loosen each spark plug 1 or 2 turns.

3. Brush or air blast away any dirt from around the spark plugs.

4. Remove the spark plugs one at a time. Place each plug in a tray marked with the corresponding cylinder numbers.

Installation Procedure

Factory service manual diagram




1. Inspect each spark plug gap. Adjust each plug as needed.

Spark plug gap: 1.01 mm (0.040 in)

2. Hand start the spark plugs in the corresponding cylinders.

Caution:
Refer to Fastener Caution Fastener Caution.

3. Tighten the spark plugs for used heads to 15 Nm (11 lb ft). Tighten the spark plugs for new aluminum heads to 20 Nm (15 lb ft). Tighten the spark plugs for new iron heads to 30 Nm (22 lb ft).

4. Install the spark plug wires. Refer to Spark Plug Wire Replacement Service and Repair.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

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