It is imperative that you ensure your spark plugs are in good condition. There’s a decent chance you will need to replace your worn out spark plugs several times over the course of owning a 2002 Jeep Grand Cherokee. 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. Similar to most engine parts, spark plugs experience wear over time and eventually need replacement, 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 perhaps 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 about 20-45 minutes. This article will go over everything you will need to know about your Jeep Grand Cherokee’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 2002 Jeep Grand Cherokee
Recommended 4.7L V8 2002 Jeep Grand Cherokee Spark Plugs
For the 4.7L V8 2002 Jeep Grand Cherokee, you can use AUTOLITE 5224 spark plugs. As this 4.7L V8 features 8 cylinders, ensure that you purchase at least 8 spark plugs in total.Recommended 4.0L L6 2002 Jeep Grand Cherokee Spark Plugs
For the 4.0L L6 2002 Jeep Grand Cherokee, you can use DENSO 5018 spark plugs. As this 4.0L L6 features 6 cylinders, ensure that you purchase at least 6 spark plugs in total.These spark plugs are an exact fit for their respective engines and will match the required specifications. Make sure you purchase the correct quantity of spark plugs for your engine corresponding to the number of cylinders. Sometimes 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 is a good idea to purchase enough for your next two spark plug changes just so you will always have a new set ready. 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 exact interval determined by Jeep for the 2002 Grand Cherokee. Of course, if you drive your vehicle more aggressively or own a Grand Cherokee 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 needs a spark plug replacement earlier than the recommended schedule, such as:
- Problems starting your engine
- Rough idle
- Engine misfiring
Consider that this list is absolutely 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 regular maintenance, and you are definitely doing so with the responsible decision to replace your Jeep Grand Cherokee’s spark plugs on a regular basis.
Changing spark plugs on a 2002 Jeep Grand Cherokee
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
As noted before, you should be able to do a spark plug change with some ordinary tools you most 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 for sure have in your toolbox if you do not already.
- A torque wrench is a vital tool to have in your arsenal. You will want to check your FSM (factory service manual) to determine the correct torque rating to use when putting in the new spark plugs for your 2002 Jeep Grand Cherokee to be confident 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 an issue. This tool can help you diagnose the definite problem.
- A set of spark plug sockets – These come in very handy because many standard sockets are not deep enough for spark plugs. Also, 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 change it if necessary. Most plugs will come pregapped, but if not, you should for sure have one of these.
- I also highly recommend you have a feeler gauge as it makes it a bit easier to check the exact gap, and it is useful for quite a few other jobs.
Tips for changing spark plugs on your 2002 Jeep Grand Cherokee
Be sure to review the video above before you attempt to repair the spark plugs on your 2002 Jeep Grand Cherokee, as well as review your FSM (factory service manual) or owner’s manual. Also, see the tips included below here to help you as you perform this repair.
- Your engine should be completely cold before you replace your spark plugs. You should wait at least 30 minutes after your engine has been running before attempting to replace the spark plugs on your 2002 Jeep Grand Cherokee
- 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 Jeep Grand Cherokee or any other vehicle.
- It’s not a bad idea to use 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.
- The most important thing 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.
- 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 light coating of anti-seize to the threads of their spark plugs, especially on older vehicles.