How to Change Out the Spark Plugs on Your Vehicle's Engine

Something to consider, which most vehicle owners seem to overlook, is when and how to change out the spark plugs in your vehicle. You should try to change out your spark plugs at least every 30,000 miles. In this article we will go through the step by step process of changing out your spark plugs.

The first thing you will want to do is make sure your vehicle is in gear or park and apply the emergency brake. Make sure your engine has been allowed to cool before startingn the job. Lift the hood of your car and you will notice that there are a row of thick single wires, one for each cylinder spark plug screwed into the engine. Each spark plug has a specific wire assigned to it, so always change the spark plugs one at a time to ensure that these wires get installed on the correct spark plug.

Start by pulling the L-shaped rubber cover and wire from the spark plug terminal. Next use air and blow any dust or dirt away from the area around the spark plug. Use a ratchet wrench and the appropriate sized socket to loosen the spark plug. You may need to use an extension or a flexible attachment on your socket to reach the spark plug. Make sure that the socket is completely on the spark plug to prevent damage from occurring. Turn the ratchet counter clockwise to break the spark plug loose and remove it from the engine block.

After removing the plug, observe its condition. A spark plug in good condition will be grey or tan and fairly clean while a spark plug that is black or has deposits on it would indicate an engine problem. Also look for any signs of physical damage to the core nose or electrode, if these areas are damaged in anyway then replace the spark plug.

Before installing the new spark plug you will first need to make sure it has the proper gap. Check your automobile repair manual for the proper gap for your specific engine and spark plugs. Use a spark plug gapping tool and insert it between the spark plug center electrode and the side electrode of the plugs tip. If the gap is too large just lightly tap the end of the plug to close it up until the gap is correct. If the gap is too small then bend the side electrode up gently until the gap is correct.

Once you determine that the gap on the plug is correct the install the plug hand tight. Use the ratchet and socket and tighten the plug. Make sure the spark plug is snug without over tightening. Over tightening the plug can result in stripping out the threads "do not over tighten". Re-install the plug wire and repeat this same process with the remaining plugs. Double check each plug to insure that you have gapped them according to your owners manual.

After you have finished gapping and installing all of the spark plugs, start your engine and if it is running rough turn it off and check to make sure all the plug wires have been pushed firmly into place. This will complete your spark plug installation.