One of the most important aspects of vehicle maintenance is ensuring your spark plugs are in good working order. There’s a good chance you will need to replace your worn out spark plugs several times over the course of owning a 1995 GMC P3500. Spark plugs are one of the most important parts inside your engine as they start 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 swapped out for new replacements, but fortunately this is a repair you can do yourself. Odds 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’ll need to know about your GMC P3500’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 1995 GMC P3500
AUTOLITE AP25[/caption]For any 1995 GMC P3500, you can use AUTOLITE AP25 spark plugs. These will be an exact fit and will match the required specifications of your engine. Make certain that you purchase the correct amount of spark plugs for your engine corresponding to the number of cylinders. Occasionally manufacturers will bundle spark plugs in quantities that make it difficult to buy the exact amount you need for your engine. In this case, it can’t hurt 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 now at an affordable 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 1995 P3500. Of course, if you drive your vehicle more aggressively or own a P3500 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 potentially need a spark plug replacement prematurely, such as:
- Engine misfiring
- Rough idle
- Problems starting your engine
Note that this list is certainly not comprehensive, and these problems on their own do not definitively 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 P3500’s spark plugs on a regular basis.
Changing spark plugs on a 1995 GMC P3500
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) or an equivalent Haynes or Chiltons manual. The video shown below does a good job of outlining the process.
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 definitely have in your toolbox if you don’t already.
- A set of spark plug sockets – These come in very 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 increase or decrease 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 comes in handy for countless other jobs.
- A torque wrench is a vital tool to have in your arsenal. You will want to check your factory service manual to determine the correct torque rating to use when installing the new spark plugs for your 1995 GMC P3500 to be certain they are installed properly.
- 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 a problem. This tool can help you diagnose the exact problem.
Tips for changing spark plugs on your 1995 GMC P3500
Ensure you review the video above before you attempt to repair the spark plugs on your 1995 GMC P3500, 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 perform this repair.
- You should replace spark plugs on a cold engine. Wait at least 30 minutes after your engine has been running before attempting to replace the spark plugs on your 1995 GMC P3500
- Before starting, remove the negative terminal of your battery. It’s a good idea to disconnect the battery anytime you work on the electrical system of your GMC P3500 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.
- 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 light coating of anti-seize to the threads of their spark plugs, especially on older vehicles.
- You might consider using 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.