One of the most important aspects of vehicle maintenance is ensuring your spark plugs are in good working order. There’s a likely probability you will need to replace your old and worn out spark plugs several times over the course of owning a 1997 Subaru Impreza. Spark plugs are one of the most vital components 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, 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 complete process of changing your spark plugs should take approximately 20-45 minutes. This article will go over everything you should need to know about your Subaru Impreza’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 1997 Subaru Impreza
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 exact interval determined by Subaru for the 1997 Impreza. Of course, if you drive your vehicle more aggressively or own a Impreza 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 prematurely, such as:
- Engine misfiring
- Rough idle
- Problems starting your engine
Note that this list is of course not comprehensive, and these problems on their own do not necessarily 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 Subaru Impreza’s spark plugs on a regular basis.
Changing spark plugs on a 1997 Subaru Impreza
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 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 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 more straightforward to check the exact gap, and it is helpful for countless other jobs.
- A torque wrench is a vital tool to have in your toolbox. You should 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 1997 Subaru Impreza to be confident they are installed properly.
Tips for changing spark plugs on your 1997 Subaru Impreza
- You should replace spark plugs on a cold engine. Ensure you wait at least 30 minutes after your engine has been running before attempting to replace the spark plugs on your 1997 Subaru Impreza
- 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 small amount of anti-seize to the threads of their spark plugs, especially on older vehicles.
- Before you begin, 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 Subaru Impreza or any other vehicle.
- It’s not 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.
- 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.