Spark plugs create a tiny bolt of electricity to ignite the air and fuel mixture. This internal combustion moves the pistons that make your engine run. Although spark plugs are incredibly durable, they do eventually wear out and require replacing.
For older vehicles, this is something you could do yourself. But with modern cars, spark plugs are often blocked by engine components or computer circuits. You would need to take your vehicle to a service department, such as the one at Giant Cadillac in Visalia, CA, so our certified auto-technicians can handle spark plug replacements.
Why Spark Plugs Turn Bad
Time is usually the chief reason that spark plugs go bad. They typically have an anti-corrosion coding that protects them against damaging elements from the engine. But over time, this coating can wear down and oil, carbon, and other combustion byproducts can build up on the plug causing them to wear out.
Another cause is a bad fuel filter that allows particles, dirt, and other contaminants to enter the fuel system. This grime wears down your spark plugs and erodes the insulators. Electrical shorts send sparks across the engine instead of just in the areas needed for ignition. Your engine then misfires and the timing becomes ineffective, which reduces performance and gas mileage.
When to Replace
It’s time to replace your spark plugs when any of the following happens. Note that if you’re planning to change them yourself, check to make sure that the spark plug wires and boots are also in good condition. This is something our techs do automatically when they’re dealing with your spark plugs.
The maintenance schedule says so.
All Cadillac models will have a maintenance schedule that suggests when you should replace your spark plugs. For example, the 2021 Cadillac Escalade recommends spark plug replacement at around 90,000 miles. However, some vehicles may require changes in as little as 30,000 miles or closer to 100,000 miles. If your owner’s manual does not state when you should replace your spark plugs, please give our Service Department a call for information.
The check engine light comes on.
The check engine light may come on for a minor problem, such as a loose fuel tank cover, which only demands that you tighten it, which is a quick fix. This light can also come on for a more serious problem, such as when your spark plugs are worn or starting to fail. An engine misfire can turn on the light. But if the light starts blinking, you may have a potentially serious problem on your hands and you should replace the spark plugs as soon as possible.
You’re filling up too often.
When your spark plugs begin wearing down, your engine will not operate as efficiently. This increases fuel consumption because the spark plugs do not efficiently burn the fuel that ends up in your engine. You then have to go to the gas station more often. Replacing the spark plugs can improve your fuel economy once more.
You have trouble starting your car.
A worn-out spark plug will take longer and expend more effort in creating the spark that runs your engine. If you have trouble starting or your vehicle starts stalling when you’re starting up, the problem could be with the spark plugs or damaged spark plug wires. However, if your car is lacking any power and cannot start, it’s more likely that the battery is drained.
Acceleration is bad
If you have been driving your vehicle for some time, you probably know how quickly it accelerates. If you discover that your car is not as responsive as it used to be, especially when you’re trying to pass somebody on the highway, the problem may be due to worn spark plugs.
The engine idles terribly.
You typically will not notice an engine if it’s functioning properly because the sounds it makes a quiet and regular. If you hear your power plant making all kinds of strange noises, such as knocking, rattling, or pinging, it may be due to worn spark plugs.
Your emissions checks are bad.
If you fail your California emissions test, it could be because of worn spark plugs or spark plug wires. Replacing both can overcome this issue, so try to get this done before your next test. But keep in mind, other factors may make you fail the test, such as a weak battery, leaking hoses, or dirty oil.
