There’s a good chance you will be required to replace your old and worn out spark plugs several times while you own a a 2012 Toyota Highlander. Spark plugs are one of the most important 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 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. Chances 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 entire process of changing your spark plugs should take about 20-45 minutes. This article will go over everything you should 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 2012 Toyota Highlander
For any 2012 Toyota Highlander, you can use ACDELCO 21 spark plugs. These will be an exact fit and will match the required specifications of your engine. Ensure you purchase the correct amount of spark plugs for your engine corresponding to the number of cylinders. Sometimes 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 not a bad 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 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 specific interval determined by Toyota for the 2012 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 telltale signs of a car that needs 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 2012 Toyota Highlander’s spark plugs on a regular basis.
Changing spark plugs on a 2012 Toyota Highlander
This is a process you should be able to do on your own with some commonplace 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.
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 for sure have in your toolbox if you don’t already.
- A spark plug gap tool. This allows you to check the gap of your spark plugs and modify it if necessary. Most plugs will come pregapped, but if not, you should absolutely 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 helpful for quite a few other jobs.
- A torque wrench is a essential tool to have in your arsenal. You will want to check your FSM (factory service manual) or owner’s manual to determine the correct torque rating to use when installing the new spark plugs for your 2012 Toyota Highlander 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.
- 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!
Tips for changing spark plugs on your 2012 Toyota Highlander
Be sure to review the video above before you attempt to repair the spark plugs on your 2012 Toyota Highlander, as well as review your FSM (factory service manual). Also, see the tips included below here to help you as you complete this repair.
- It isn’t a bad idea to use 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.
- 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.
- 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 2012 Toyota Highlander
- Before starting, disconnect the negative terminal of your battery. You should always disconnect the battery anytime you work on the electrical system of your Toyota Highlander or any other vehicle.
- 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.