Spark Plugs Archives - UnderhoodService
Mayhew Tools Introduces Spark Plug Thread Chaser

This tool is made in USA and is backed by a lifetime warranty.

Ignition Systems

The ignition coil is a very simple and robust circuit.

Do You Know The Cause Of A No-Spark Condition?

A no-spark condition could be the result of communication errors or missing data from a dead module.

Spark Plug Evolution

Spark plugs have changed over the years.

Modern Vehicles Need Precious Metals 

Modern ignition systems require dual precious metal spark plugs capable of supplying the highest voltage outputs to date

Spark Plugs and Wires (VIDEO)

Wires should be replaced at the same time as spark plugs. This video is sponsored by Autolite.

How Can Something So Small Be So Important? (VIDEO)

Too small of a gap can lead to a weak spark, and too large a gap can lead to misfires. Sponsored by Autolite.

The Importance of Proper Spark Plug Torquing

Whenever you install new spark plugs in your vehicle’s engine, there are some crucial considerations to keep in mind. For those who have installed plugs before, proper plug gapping usually comes to mind first. But another important factor in getting the most out of a new set of spark plugs is to precisely torque them

Spark Plug Replacement

Here are some tips to follow when replacing a spark plug.

Five Spark Plug Service And Replacement Tips

Most articles will tell you to use a torque wrench, but they never explain why.

BMW Spark Plug Replacement

Here are a few things that you need to know before replacing spark plugs in a BMW.

Diagnosing Driveability Problems

Understanding what comes out through the exhaust valve is critical to solving any emissions or driveability problem.