Time: 30min-1hr

Difficulty - Moderate (access)

Cost - $60-175 (plug type, ignition wires replaced same time)

WHY

Good spark plugs help ensure an efficient fuel burn which contributes to fuel economy and performance. Worn-out spark plugs increase electrical resistance and strain on ignition components such as the coils and ignition wires. They also cause poor combustion, wasting fuel and reducing horsepower.

WHEN

The interval for replacing platinum or iridium spark plugs can range from 60,000-150,000 miles depending on driving conditions and vehicle health. Planning to replace spark plugs around 100,000 miles is a nice round number that falls in the middle of that range.

METHOD

Spark plugs are replaced by removing the ignition cable and then removing the plug from the cylinder head. A magnetic socket (or socket with a rubber boot) can make removal and installation easier. The new spark plug is then properly gapped and reinstalled to the specified torque.

Platinum and Iridium plugs typically come pre-gapped for optimal spark, but it's a good idea to check the gap with a feeler gauge in case there are any outliers from shipping. The spec for the 2007-2013 GM 5.3L is .060" for platinums, or .040" for iridiums.

Watch the video below to see how the spark plugs were replaced on a 2007-2013 era Chevy Silverado 1500 with the 5.3L engine.