Step-by-step guide on how to replace a spark plug in your car engine. Learn the tools you need and the process to safely swap your old spark plugs.
Automotive
FigsiT Project Rating
Take care
The main risk is damaging the engine threads or causing a misfire by installing plugs incorrectly. Always work on a cool engine to avoid burns.
Safety gear: Safety glasses, Work gloves
Where to find it
The spark plugs are located on the engine block, usually under thick rubber wires or plastic ignition coil packs. Their exact position varies by engine layout; consult your owner's manual for the specific location on your vehicle.
What it looks like
A small metal component with a ceramic top and a threaded base, often hidden under a rubber boot or a plastic coil pack.
Tools Required (9)
Not sure what something is? Tap it to see a picture.
Parts (4)
Get the exact part. Parts change by year, make, model and engine. Give the parts store all four, or your VIN (it's on your registration, on the sticker inside the driver's door, and on the dashboard where it meets the windshield on the driver's side), and they'll match the right part for your vehicle.
Tell FigsiT your exact setup and get your personal tools list, materials, and steps in seconds.
Step-by-Step Instructions
1.
Turn off the engine and let it cool completely before starting to avoid burns from hot engine components.
2.
Give the parts store your year, make, and model so they match the exact spark plugs for your engine.
3.
Stand facing the front of the car and open the hood to locate the spark plug wires or ignition coils, which are usually on top of the engine block.
4.
Clean the area around the spark plug wells with a rag or compressed air to prevent dirt from falling into the engine cylinder once the plug is removed.
5.
Remove only one spark plug wire or ignition coil at a time to ensure you do not mix up the firing order. Why: replacing one at a time prevents engine misfires caused by incorrect wire routing.
6.
Use the spark plug socket and ratchet to turn the old spark plug counterclockwise until it is loose, then remove it by hand.
7.
Check the gap of the new spark plug using a gap gauge if it is not pre-gapped, ensuring it matches the specification in your owner's manual.
8.
Thread the new spark plug into the hole by hand first to ensure it is not cross-threaded, then tighten it with the socket wrench to the manufacturer's torque specification.
9.
Apply a small amount of dielectric grease to the inside of the spark plug boot before pushing it firmly back onto the new plug until you feel or hear a click.
10.
Repeat these steps for each remaining spark plug one at a time until all have been replaced.
Want to see it done first?
Take it one step at a time, then look back at how far you've come.
FigsiT. Get the answers now. figsit.com/guide/replace-spark-plug
Tell FigsiT your exact setup and get your personal tools list, materials, and steps in seconds.