How To Replace A Spark Plug In 6 Steps

Changing the spark plugs in your GMC vehicle is one of the easiest maintenance jobs you can do at home. With this tutorial, we will guide you through the process.

How Much Money You’ll Save By Replacing The Spark Plugs Yourself

Chevy spark plug

Image Credit: PaulsTravelPictures

Regardless of your car’s model or generation, hiring a shop to replace the spark plugs for you isn’t going to be cheap. Performing this job yourself will save you a nice chunk of cash.

Regardless of whether you’re replacing one or all of your spark plugs, you’ll save at least $100 by doing it yourself. This is a project that takes only 15-30 minutes, but shops will charge a minimum of 1 hour at $100 per hour. They’ll also charge you a markup on the OEM replacement spark plugs.

It’s much cheaper to order genuine OEM spark plugs from us at a much lower price and then replace the spark plugs yourself with this tutorial. It’s based on the 6.0L engine in older Sierra 2500s, but you can follow it with another GMC model. Just keep in mind that the spark plugs are easy to access in older V8 engines because there’s not an engine cover. So additional steps may be required if you’re working on a newer motor with a cover.


Before starting, be sure to have all the following tools on hand:

  • 5/8” deep socket or spark plug socket
  • Ratchet
  • Spark plug gauge gap tool
  • Torque wrench

Replacing The Spark Plugs In Your Engine

When you have everything ready, follow these steps:

  1. With the gap tool, measure the gap to make sure that the spark plug is gapped correctly.
  2. Reach down to the first spark plug and then disconnect the spark plug wire.
  3. With the 5/8” deep socket or spark plug socket, twist out the spark plug. Be careful not to break the spark plug during the process because it’s pretty hard to get all the pieces out.
  4. Twist in the new spark plug by hand until it’s threaded in snugly.
  5. Use your ratchet and tighten up the new spark plug. Be sure to use the torque specifications outlined in the owner’s manual.
  6. Plug the spark plug wire back onto the new spark plug.
  7. Repeat that process for the rest of the spark plugs in your car.

Please send us an email via our contact form if you have any questions about the replacement process.