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Changing Your Lexus Spark Plugs Can Save You $400

If your Lexus has a significant number of miles on it, you are likely overdue for a spark plug change. Here’s how to DIY and save $400.


Spark Plugs are an Important Part of Car Maintenance

Maintaining your vehicle to run properly for as long as possible can save you a considerable amount of money in repairs. Particularly when it comes to preventive maintenance to head off any not just potential but eventual problems that will occur given enough time and wear and tear based on your vehicle’s driving conditions.

Fortunately, some of those maintenance tasks are typically just 1-2 times in the lifetime of your vehicle before it’s time to move onto a new model and let someone else take the responsibility of keeping your old car running. A good example is that of spark plugs.

Symptoms of Spark Plugs Going Bad

As long as your vehicle has been well maintained and driven responsibly throughout its ownership, and the spark plugs used are OEM and not a less expensive or wrong type used, your spark plugs should need to be changed only once or twice during the ownership of your car----unless you are planning on keeping your car for the long haul.

According to recent J.D. Power’s article written by Dustin Hawley in an article titled “How Long Do Spark Plugs Last?”:

The average interval is from 20,000 to 40,000 miles. On a serviceable car with good quality fuel, the iridium ignition elements can last for about 75,000 miles, and the standard nickel ones for about 30,000 miles.”

Symptoms that your plugs could be going bad include:

  • Hard starts
  • Rough idling
  • Engine misfires
  • Lack of acceleration
  • Reduced gas mileage

Which makes sense due to that the job of spark plugs is to ignite the fuel-air mixture that keeps the engine running. Because the engine operates at a broad range of RPMs the firing of the spark plugs has to be optimal, and to be optimal they have to be in great condition. In other words, no fouling of oil or carbon deposits on the electrodes, no excessive wearing away of the electrodes, and/or cracking of the insulator body on any of the spark plugs.

Other conditions can mimic spark plug problem symptoms such as using old or bad fuel, cracks in the spark plug wires, and timing chain related issues. However, if the symptoms meet the diagnostic criteria of bad plugs, it is cheapest and easiest to start with the plugs first before moving onto other potential causes.

What Plugs Are in Your Car and What is Their Condition?

There is no guarantee that if you take your car to a service center or garage that the correct spark plugs will be installed. Worse yet, it’s not something you can easily verify just by popping open the hood and seeing for yourself due to modern cars today often require some engine-related parts removal to get to the plugs in question.

In fact, it is not uncommon for used car shoppers to discover that the used car they bought has the wrong spark plugs installed necessitating a replacement to achieve better performance and possibly avoid damage to their new used car.

That was part of the message in a recent Mike the Backyard Mechanic YouTube channel episode where the host demonstrates how to DIY when changing the spark plugs on your Lexus. Particularly for Lexus models between 2005 and 2015.

Follow along with the host as he goes through spark plug replacement on his old Lexus and offers some caveats in a joking manner that are actually quite serious such as:

  • When not to use anti seize lubricant on a spark plug
  • Why plug boot lube is important
  • Spark plug gapping
  • Using the correct torque on spark plugs
  • Being sure to cover the manifold port holes to avoid dropping a nut or bolt into the engine

That said and done, here is the video worth watching in its entirety as long as you can overlook the host’s style of humor and realize the useful gems of information he delivers.

At the very least, even if you decide not to DIY your spark plugs, the video shows why it costs so much to have a garage do it.

Save $400 Changing Your Own Spark Plugs

Be sure to check out these other articles that cover spark plug maintenance:

Timothy Boyer is an automotive reporter based in Cincinnati. Experienced with early car restorations, he regularly restores older vehicles with engine modifications for improved performance. Follow Tim on Twitter at @TimBoyerWrites for daily news and topics related to new and used cars and trucks.

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