How To Tell If Your Toyota Corolla Spark Plugs Are Bad (Plus Causes And Solutions)

If you own a Toyota Corolla, you know that it’s an incredibly reliable car. However, like other cars, it is also affected by various problems, including a bad spark plug. Now you wonder how to tell if your Toyota Corolla spark plugs are bad (plus causes and solutions)

Over time, the electrodes on the spark plugs wear down due to repeated use, which causes them to produce a weaker spark or fail to ignite the fuel and air mixture properly. Regular replacement of the spark plugs is the most effective solution for normal wear and tear.

In this article, we’ll explore the signs of bad spark plugs in your Toyota Corolla, the causes of spark plug problems, and the solutions for resolving them. By learning to identify and fix spark plug issues, you can keep your Toyota Corolla running at peak performance and avoid costly repairs down the road.

Why Is Spark Plug Important In A Toyota Corolla?

Spark plugs are an essential component of any gasoline engine, including the one in a Toyota Corolla. They play a critical role in the ignition, which powers the engine and enables the vehicle to move.

Spark plugs are responsible for producing the spark that ignites the fuel and air mixture inside each engine’s cylinder. This combustion process creates the power needed to propel the vehicle. If the spark plugs in a Toyota Corolla are not functioning correctly, the engine will not run efficiently.

It may misfire or stall, leading to poor performance and reduced fuel efficiency. Over time, bad spark plugs cause other engine components to fail, resulting in costly repairs. Therefore, it is essential to ensure that the spark plugs in a Toyota Corolla are always in good working condition to maintain the vehicle’s performance and longevity.

How To Tell If Your Toyota Corolla Spark Plugs Are Bad?

Here are some common signs that your Toyota Corolla’s spark plugs may be bad:

  • Engine Misfires: If you feel a hesitation or stumble in your engine’s performance, especially when accelerating, it is due to a bad spark plug.
  • Reduced Fuel Efficiency: A bad spark plug causes your engine to work harder, leading to decreased fuel efficiency and increased emissions. Because of a bad spark plug, you will lose fuel quickly.
  • Rough Idle: The engine is idling roughly, or shaking could signify a misfiring spark plug.
  • Difficulty Starting: Slow to start or requires multiple attempts to turn over in a Corolla due to a faulty spark plug.
  • Poor Acceleration: Corolla is sluggish or lacks power when you press the accelerator, it could be a sign of a bad spark plug.

What Are The Causes Of Bad Spark Plugs In Toyota Corolla

There are several factors that can cause spark plugs to go bad in a Toyota Corolla, including:

  • Normal Wear And Tear: Over time, spark plugs can wear out due to regular use, especially if they are not replaced according to the manufacturer’s recommended maintenance schedule.
  • Oil And Fuel Contamination: If oil or fuel leaks into the engine, it causes the spark plugs to become fouled and fail to function properly.
  • Overheating: Excessive engine temperatures also cause the spark plugs to overheat and burn out.
  • Incorrect Gap Size: If the gap between the electrodes on the spark plug is too wide or too narrow, it can cause the engine to misfire or perform poorly.
  • Poor Quality Or Incorrect Type Of Spark Plug: Using the wrong type of spark plug or low-quality spark plugs lead to poor engine performance and premature wear.

How Do You Fix Toyota Corolla Spark Plugs?

Fixing bad spark plugs in your Toyota Corolla involves the following steps:

How Do You Fix Toyota Corolla Spark Plugs

Step-1: Locate The Spark Plugs

The location of the spark plugs can vary depending on the specific model and year of your Toyota Corolla. Consult your owner’s manual or a qualified mechanic to determine where the spark plugs are located.

Step-2: Remove The Old Spark Plugs

Use a spark plug socket to remove the old spark plugs from the engine carefully. Be sure to inspect each spark plug for signs of damage, wear, or to foul.

Step-3: Install New Spark Plugs

Using the recommended spark plugs for your Toyota Corolla, carefully insert them into the engine and tighten them to the recommended torque setting.

Step-4:  Check The Gap

Using a spark plug gap tool, check the gap between the electrodes on each spark plug to ensure it is set to the correct specifications. Adjust the gap as necessary.

Step-5: Reconnect Ignition Coils And Wires

Reconnect the ignition coils and wires to each spark plug, being careful not to overtighten.

Step-6: Test The Engine

Start the engine and check for proper operation. If necessary, adjust the spark plugs or engine settings to ensure optimal performance.

How Much Does It Cost To Replace Toyota Corolla Spark Plugs?

The cost to replace spark plugs in a Toyota Corolla varies depending on a few factors, such as the type of spark plugs required, labour costs in your area, and whether or not any additional repairs or maintenance are needed.

How Much Does It Cost To Replace Toyota Corolla Spark Plugs

However, on average, you can expect to pay between $100 and $300 for a professional mechanic to replace the spark plugs in your Toyota Corolla. Keep in mind that the cost may also vary depending on your Corolla’s specific year and model.

Some models are more labor-intensive to access the spark plugs, which increases the cost of the service. It’s important to have your spark plugs replaced on a regular basis to ensure that your engine is running smoothly and efficiently. Neglecting spark plug replacement can lead to more serious engine issues down the line, which are much more expensive to repair.

Final Words

Maintaining the spark plugs in your Toyota Corolla is an essential part of keeping your vehicle running smoothly and efficiently. We hope after reading this article, you are now aware of how to tell if your Toyota Corolla spark plugs are bad (plus causes and solutions).

So, if you notice any of the signs of bad spark plugs, such as misfires, rough idle, or difficulty starting, it’s important to have your spark plugs inspected and replaced if necessary.

Remember to use the correct spark plug type and follow the recommended maintenance schedule to ensure optimal performance and avoid costly repairs. If you have any questions or concerns about your Toyota Corolla’s spark plugs, don’t hesitate to consult with a qualified mechanic for advice and assistance.