How to Repair Car/Auto Spark Plugs the Correct Way

First assess the situation. Use an OB2 certified device and connect it into the 16 pin port found just to the left of the center of your dashboard. Read the error messages. If the OB2 reader is throwing camshaft misfire errors then your spark plugs need to be changed! It may be because they burned out in a natural way or because there is low pressure in at least one camshaft which caused just a spark plug or two to burn out and corrode. Gather the tools that you'll need. You'll want a ratchet set with a spark plug socket, a 3 inch extension, angle joints, the spark plugs, anti seize lubricant for the plugs and the spark plug boots (part of the spark plug wiring). Remember that spark plugs are the windows into the engine! Use a pressure gauge for camshafts to make sure that the engine cylinders have full pressure still.

Iridium spark plugs go for 100,000 to 120,000 miles. Copper ones go for half that time but are about three dollars instead of six per plug. I go for the higher quality Iridium spark plugs but the choice is up to you. If you get the copper spark plugs, that's just more practice for you!

Check the gaps of the spark plugs with a gap tester. A spark plug gap tester is one dollar at an auto parts store. Make sure the gaps are consistent with how wide the gap is supposed to be. Check the instructions which are usually on the box to see the optimal gap distance.

Open up the hood. There is a button or lever for this by the driver's side of the car. Make sure that the car is turned off. Remove The engine cover that goes over the engine block gently and put this aside. Wear plastic gloves. There will be grease on the spark plugs.

Take out your ratchet wrench. Put on the spark plug extension. Use Duct (Duck) tape to secure the extension to the rachet. This is done because the extension grips onto the spark plugs inside the engine block and gets stuck often. This wastes a ton of time when that happens!

First remove the wire coils over the spark plugs. These often block access to the spark plugs. Put the spark plug extension and ratchet over the first spark plug closest to you. Turn the ratchet counter clockwise until the spark plug comes out. Remove the spark plug boot which connects the spark plug wires to the car.

In my experience, I've done over dozens of spark plugs so I'm really good at it. However, doing it the first time will take you longer then someone like me with experience. Be patient but work steady and don't give up. Things might not go your way and you'll have to improvise. Always remember a bit of duct tape and super glue can fix alot of problems.

Inspect the spark plug. Does it look burnt? If so you need to replace it. If so put antiseize lubricant onto the spark plug threads of the new spark plug. Put a new spark plug into the ratchet extension made for it. Insert the spark plug into the spark plug hole. Use your arm strength to torque the spark plug into the hole. Once tight torque a half turn and your done with that plug. Put antisieze boot gel into the spark plug boot or on the white part of the plug. Put the spark plug boot back on. Later on you'll ratchet the coil back on. It's often a T34 screw and extension for that on the ratchet. Repeat this process for each spark plug until done. Put the cover back on. Test the car and make sure it rides smooth.

Sometimes the duct tape comes off of the ratchet extension and the spark plug (the older one) or new one is stuck in the hole with the extension on it. To get the extension out, go to the hardware store and purchase a ninety degree 12 inch needle nose plier. This can be used to pull out the extension that got stuck into the spark plug hole. You'll also want a mirror on a metal rod tool to see better and magnetic pan for it.

If this happens don't panic. You can go to your local trusty hardware store and buy a spark plug re-threading kit. It'll come with a re-threader and the rings to put in the hole.

Put the re-threader onto the end of a 8 inch extension bar for the ratchet. Put it in the spark plug hole. Turn the ratchet clockwise and the re-threader will put new threads into the damaged spark plug hole.

Start the engine again. This will blow any metal fragments out of the hole. Put the thread ring into the hole with the ratchet extension. Next, clip off the tang. Put the spark plug back in and the spark plug wire/coil back on. Then start the car up to test it out.