1996 GMC G3500 Spark Plug Replacement Guide

Spark plugs are one of the most critical components inside your engine that need to be maintained. There’s a good probability you will need to replace your old and worn out spark plugs several times during your ownership of a 1996 GMC G3500. Spark plugs are one of the most critical components inside your engine as they trigger the entire combustion process that starts and keeps your engine running for many thousands of miles. Similar to most engine parts, 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 roughly 20-45 minutes. This article will go over everything you’ll need to know about your GMC G3500’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 1996 GMC G3500

BOSCH 6708[/caption]For any 1996 GMC G3500, you can use BOSCH 6708 spark plugs. These will be an exact fit and will match the required specifications of your engine. Ensure you purchase the correct number of spark plugs for your engine corresponding to the number of cylinders. Occasionally manufacturers will bundle spark plugs in quantities that make it impossible to buy the exact amount you need for your engine. In this case, it is a good idea to purchase enough for your next two spark plug changes just so you will always have a new set ready to go. 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?

As a general recommendation, 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 1996 G3500. Of course, if you drive your vehicle more aggressively or own a G3500 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

As a quick note, keep in mind that this list is absolutely not comprehensive, and these problems on their own do not definitively point to the spark plugs being the standalone culprit. However, the best way to prevent any issues with your vehicle is to take care of it with regular maintenance, and you are definitely doing so with the responsible decision to replace your GMC G3500’s spark plugs on a regular basis.

Changing spark plugs on a 1996 GMC G3500

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

Helpful Tools

A set of spark plug sockets is a must have. Certain spark plugs and engines make this job nearly imposible without one
As noted before, you should be able to complete a spark plug change with some ordinary tools you probably 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 general tools that you should definitely have in your toolbox if you do not already.

  • 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 not, you should for sure have one of these.
  • 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 lots 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 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 inserting the new spark plugs for your 1996 GMC G3500 to be confident they are installed properly.

Tips for changing spark plugs on your 1996 GMC G3500

It is a great idea to have some dielectric grease handy.
Ensure you watch the video above before you attempt to repair the spark plugs on your 1996 GMC G3500, as well as review your FSM (factory service manual) or owner’s manual. Additionally, we have some tips below here to help you as you do this repair.

  • Your engine should be completely cold before you replace your spark plugs. Ensure you wait at least 30 minutes after any kind of operation before attempting to replace the spark plugs on your 1996 GMC G3500
  • Before beginning, disconnect the negative terminal of your battery. It is wise to disconnect the battery anytime you work on the electrical system of your GMC G3500 or any other vehicle.
  • It isn’t a bad idea to use dielectric grease when installing new spark plugs. You can apply a a very light coating 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.
  • One of the most important things to remember 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.
  • Take this (unofficial advice) lightly 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 tiny amount of anti-seize to the threads of their spark plugs, especially on older vehicles.

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