A lot of people come to me for car advice, and here’s one thing I’ve noticed: everyone thinks they know about spark plugs, but almost no one really does. So I decided to make this column all about spark plugs, because trust me, your engine relies on them every day–which means you do, too. That’s why I want you to get familiar with these little buggers. Let’s dive right in with a little Q&A.
What do spark plugs do?
Here’s a fun fact about your engine: unless you’re driving an electric car, in which case this article definitely isn’t for you, you’ve got what’s known as an ICE, which stands for “internal combustion engine.” Now, combustion requires a spark, doesn’t it. See where I’m going with this? Spark plugs are a crucial part of your engine because they’re what makes that combustion happen, both at ignition and while the engine moves through each combustion cycle during operation. When the plugs aren’t doing their job, your engine’s not getting the full combustion benefit, so everything from acceleration and fuel economy to engine smoothness is going to be negatively affected.
How do I know when to replace spark plugs?
My rule of thumb is that if something seems funny about your engine, you should check the spark plugs first. If you’re a hands-off kind of car owner, of course, you’ll just take it to your mechanic and get it diagnosed. But if you want to inspect the plugs yourself, it’s a pretty easy job. Check your owner’s manual to find out where the plugs are located, and then pop the hood and have a look. If the plugs appear dirty, that could mean you’ve got an oil leak or excessive carbon deposits–and if they look damaged, your engine might be running too hot or misfiring.
Keep in mind, though, that even if they look fine, they might be past their prime. Consult your owner’s manual for when to replace spark plugs, too, and if you think you’re past due, I’d recommend replacing them, just to be safe.
Can I replace my own spark plugs?
Now, I said you could check them, but I didn’t say you should try to replace them! Truth is, for a seasoned backyard mechanic, popping the old plugs out and putting new ones in is pretty straightforward. But if you haven’t done it before, you should probably have someone like me looking over your shoulder the first time through. I know the internet’s full of DIY guides on how to change spark plugs, but there’s some serious wrenching going on here–literally. You need a socket wrench, and you may need a specific spark-plug socket and other accessories as well. Plus, there’s a fairly advanced technique called “gapping” that may or may not be required, depending on your vehicle’s age and other factors.
Promise me this: if you do try one of those tutorials on how to change spark plugs, please, wait for the engine to cool off first. I’m talking four hours, minimum. Those plugs are responsible for combustion, remember? Better safe than scalded!
What about cleaning spark plugs?
Here’s where I differ from a lot of DIY-ers. You’ll find various folk remedies for cleaning spark plugs, but for peace of mind, I say just swap ‘em out if they’re that dirty. Because how much money are you really saving, right? Twenty bucks? Fifty? Spark plugs are a car owner’s dream, really, because they’re that rare important engine part that’s also inexpensive. If it’s my car, I believe my engine’s worth that kind of investment, every day of the week. Give it the shiny new plugs it deserves.
What do you think?
I’ve seen a few spark plugs in my day, but I’ll be the first to admit, this article isn’t the last word on the subject. Got anything to contribute? See things differently? Chime in with a comment, and help me and everyone else here understand where you’re coming from.