There’s a good chance you will need to replace your old and worn out spark plugs several times over the course of owning a 2003 GMC Sierra 2500. Spark plugs are one of the most critical components inside your engine as they start 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 replaced, 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 complete process of changing your spark plugs should take about 20-45 minutes. This article will go over everything you’ll need to know about your GMC Sierra 2500’s spark plugs, whether you need some general information or a full, step-by-step guide to performing a spark plug change.
Correct spark plugs on a 2003 GMC Sierra 2500
DENSO 4713[/caption]For any 2003 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 2003 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 now 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 specific interval determined by GMC for the 2003 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 classic signs of a car that may potentially need a spark plug replacement earlier than the recommended schedule, such as:
- Problems starting your engine
- Engine misfiring
- Rough idle
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 2003 GMC Sierra 2500
This is a process you can do on your own with some commonplace garage tools. Of course, consult your owner’s manual, as well as a factory service manual (FSM) or an equivalent Haynes or Chiltons manual. The video shown below does a good job of outlining the process.
Helpful Tools
- A spark plug gap tool. This allows you to check the gap of your spark plugs and change it if necessary. Most plugs will come pregapped, but if this is not the case, you should absolutely have one of these.
- I also highly recommend you have a feeler gauge as it makes it a bit more straightforward to check the exact gap, and it is helpful for a decent number of other jobs.
- A set of spark plug sockets – These come in very handy because many standard sockets are not deep enough for spark plugs. In addition, 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 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 an issue. This tool can help you diagnose the exact problem.
- A torque wrench is a vital tool to have in your collection. You will want to check your factory service manual to determine the correct torque rating to use when inserting the new spark plugs for your 2003 GMC Sierra 2500 to be certain they are installed properly.
Tips for changing spark plugs on your 2003 GMC Sierra 2500
- You should replace spark plugs on a cold engine. You should wait at least 30 minutes after your engine has been running before attempting to replace the spark plugs on your 2003 GMC Sierra 2500
- Before you begin, 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 might consider using dielectric grease when installing new spark plugs. You can apply a a tiny 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.