There’s a good chance you will need to replace your set of spark plugs several times over the course of owning a 2008 Chevrolet Cobalt. 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. Like most engine parts, spark plugs experience wear over time and eventually need to be replaced, 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 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 about 20-45 minutes. This article will go over everything you will need to know about your Chevrolet Cobalt’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 2008 Chevrolet Cobalt
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 Chevrolet for the 2008 Cobalt. Of course, if you drive your vehicle more aggressively or own a Chevrolet Cobalt 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:
- Engine misfiring
- Rough idle
- Problems starting your engine
Consider that this list is absolutely 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 regular maintenance, and you are definitely doing so with the responsible decision to replace your 2008 Chevrolet Cobalt’s spark plugs on a regular basis.
Changing spark plugs on a 2008 Chevrolet Cobalt
This is a process you can 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
- 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 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 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 quite a few other jobs.
- A torque wrench is a vital 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 2008 Chevrolet Cobalt to be certain they are installed properly.
- A set of spark plug sockets – These come in very handy because many standard sockets are not deep enough for spark plugs. In addition, 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 2008 Chevrolet Cobalt
- 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.
- Your engine should be cold before you replace your spark plugs. Wait at least 30 minutes after your engine has been running before attempting to replace the spark plugs on your 2008 Chevrolet Cobalt
- 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.
- 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 lessens the chance of voltage leak and helps avoid the misfortune of the boot fusing to the spark plug over time.
- Before starting, disconnect the negative terminal of your battery. It is wise to disconnect the battery anytime you work on the electrical system of your Chevrolet Cobalt or any other vehicle.