2015 GMC Sierra 2500 Spark Plug Replacement Guide

Maintaining your vehicle is an incredibly rewarding task and learning how to replace your spark plugs is a great place to start. There’s a likely chance you will need to replace your worn out spark plugs several times during your ownership of a 2015 GMC Sierra 2500. Spark plugs are one of the most vital components inside your engine as they trigger the entire combustion process that starts and keeps your engine running for many thousands of miles. Like most engine parts and components, spark plugs experience wear over time and eventually need to be swapped out for new replacements, but fortunately this is a repair you can do yourself. Chances are, if you’ve found yourself here, you have no idea how to do that, or maybe you’d just like to know what kind of spark plugs you need to buy. The entire process of changing your spark plugs should take approximately 20-45 minutes. This article will go over everything you will need to know about your GMC Sierra 2500’s spark plugs, whether you need some baseline information or a full, step-by-step guide to performing a spark plug change.

Correct spark plugs on a 2015 GMC Sierra 2500

DENSO 4713[/caption]For any 2015 GMC Sierra 2500, you can use DENSO 4713 spark plugs. These will be an exact fit and will match the required specifications of your engine. As this 2015 GMC Sierra 2500 features an 8 cylinder engine, ensure you purchase 8 spark plugs. We always try to recommend the best possible spark plugs for the money, and these spark plugs are either a factory recomendation or an equivalent replacement available in today’s market at a reasonable price.

How often should I change my spark plugs?

Very generally, it is advised that you replace spark plugs once every 20,000 to 40,000 miles. Of course, please make sure to check your owner’s manual to determine the exact interval determined by GMC for the 2015 Sierra 2500. Of course, if you drive your vehicle more aggressively or own a Sierra 2500 with some modifications, you may want to consider changing your spark plugs closer to the 20,000 miles end of that spectrum.

However, there are also telltale signs of a car that may need a spark plug replacement earlier than the recommended schedule, such as:

  • Problems starting your engine
  • Rough idle
  • Engine misfiring

Consider that this list is of course not comprehensive, and these problems on their own do not necessarily point to the spark plugs being the solitary culprit. However, the best way to prevent any issues with your vehicle is to take care of it with routine maintenance, and you are definitely doing so with the responsible decision to replace your GMC Sierra 2500’s spark plugs on a regular basis.

Changing spark plugs on a 2015 GMC Sierra 2500

This is a process you can do on your own with some ordinary garage tools. Of course, consult your owner’s manual, as well as a factory service manual or an equivalent Haynes or Chiltons manual. The video shown below does a good job of outlining the process.

Helpful Tools

We recommend having a spark plug gap tool in your arsenal. It’s an inexpensive tool that will come in handy often.
As noted before, you should be able to complete a spark plug change with some ordinary tools you likely already have. However, there are a few tools that are specific to this job that you may not have, and we also want to recommend some commonplace tools that you should absolutely have in your toolbox if you do not already.

  • A spark plug tester – this is definitely a niche tool, but it can save you a ton of time. Although we’ve discussed spark plug replacement being a good thing to replace regularly and not just when issues occur, you may also be replacing your spark plugs because of something going wrong. This tool can help you diagnose the definite problem.
  • A torque wrench is a very important tool to have in your garage. You should check your factory service manual to determine the correct torque rating to use when installing the new spark plugs for your 2015 GMC Sierra 2500 to be confident they are installed properly.
  • A set of spark plug sockets – These come in extremely handy because many standard sockets are not deep enough for spark plugs. Additionally, some spark plug holes are a bit smaller, so it requires a thinner wall like the one featured in the product here to fit. The linked product also features a magnet to keep a good hold of the spark plug so you do not drop it into your engine bay!
  • A spark plug gap tool. This allows you to check the gap of your spark plugs and modify it if necessary. Most plugs will come pregapped, but if not, you should definitely have one of these.

Tips for changing spark plugs on your 2015 GMC Sierra 2500

It is a great idea to have some dielectric grease handy.
Please make sure you review the video above before you attempt to repair the spark plugs on your 2015 GMC Sierra 2500, as well as review your FSM (factory service manual). Also, see the tips included below here to help you as you perform this repair.

  • It isn’t a bad idea to use dielectric grease when installing new spark plugs. You can apply a small amount to the inside of the boot and the ceramic part of your spark plugs. It prevents voltage leak and helps avoid the misfortune of the boot fusing to the spark plug over time.
  • Note that this is not official advice as many spark plug manufacturers advise against the use of anti-seize. However, I have heard from numerous old-school mechanics that they always apply a small amount of anti-seize to the threads of their spark plugs, especially on older vehicles.
  • Before starting, disconnect the negative terminal of your battery. It is wise to disconnect the battery anytime you work on the electrical system of your GMC Sierra 2500 or any other vehicle.
  • During this process, one of the most vital things to ensure you do is to avoid overtightening the plugs or worse, cracking them due to overtightenting. Use a torque wrench capable of lower, more precise torque ratings to be sure that you don’t make this mistake.
  • You should replace spark plugs on a cold engine. Wait at least 30 minutes after any kind of operation before attempting to replace the spark plugs on your 2015 GMC Sierra 2500

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