2005 Toyota Highlander Spark Plug Replacement Guide

There’s a good probability you will need to replace your old spark plugs several times while you own a a 2005 Toyota Highlander. Spark plugs are one of the most important parts inside your engine as they begin the entire combustion process that starts and keeps your engine running for many thousands of miles. Similar to 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. Odds are, if you’ve found yourself here, you have no idea how to do that, or potentially 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 will need to know about your Toyota Highlander’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 2005 Toyota Highlander

This is a great option for any 2005 Toyota Highlander: NGK 2978 Laser Platinum Premium Spark Plugs BKR6EP-11 – 6 PCSNEW
For any 2005 Toyota Highlander, you can use NGK 2978 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. Often, 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 not a bad 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?

In general, 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 Toyota for the 2005 Highlander. Of course, if you drive your vehicle more aggressively or own a Toyota Highlander 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 prematurely, such as:

  • Rough idle
  • Problems starting your engine
  • Engine misfiring

As a quick note, keep in mind that this list is certainly 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 organized maintenance, and you are definitely doing so with the responsible decision to replace your 2005 Toyota Highlander’s spark plugs on a regular basis.

Changing spark plugs on a 2005 Toyota Highlander

This is a process you should be able to 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 a very affordable tool that will come in handy frequently.
As noted before, you should be able to do a spark plug change with some regular 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 definitely have in your toolbox if you do not already.

  • 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.
  • 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 very important tool to have in your garage. 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 2005 Toyota Highlander to be certain they are installed properly.

Tips for changing spark plugs on your 2005 Toyota Highlander

It is a great idea to have some dielectric grease handy.
Be sure to reference the video above before you attempt to repair the spark plugs on your 2005 Toyota Highlander, as well as review your factory service manual. Be sure to check the tips shown here to help you as you perform this repair.

  • 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.
  • 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.
  • 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 Toyota Highlander or any other vehicle.
  • It isn’t a bad idea to use dielectric grease when installing new spark plugs. You can apply a a small dab to the inside of the boot and the ceramic part of your spark plugs. It lessens the chance of voltage leak and helps avoid the misfortune of the boot fusing to the spark plug over time.
  • 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 2005 Toyota Highlander

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