How to replace spark plugs on GMC Sierra 2500 HD

If you are ready to change your car's engine spark plugs It’s definitely something wrong with your spark plug. It's very important to change your spark plug when your plug is damaged. So you have to buy a new spark plug. Let’s dive right into a step by step guide on how to do it yourself.

Step One - The first thing you have to do is remove the cover over the engine body which is a black plastic cover that says inside it.

Step Two - You will find three 10mm head bolts that keep holding the black plastic cover. You will need to remove the air intake tube from the throttle body to the air filter housing. You can do this by loosening up the hose clamps at both ends of it.

Step Three - And now, you will need to remove the brace from the power steering reservoir to the thermostat housing. This is where you will see three 8mm head screws holding it together. Once you do that, you will be able to see the COPs.

Step Four - It’s time to remove it by using a 7mm or 9/32” wrench or socket. Stay patient because some of the COPs will feel impossible to get out, just wiggle and breathe. Afterwards, unplug the connector from each COP by pressing down the tab and pulling on the connector.

Step Five - Finally, the COPs are out but now you have to take a blow gun and blow out the spark plug holes. Right after you blow out the spark plug, you will be able to remove the plugs.

Step Six - Now Set the gap on the new plugs to whatever it says on your emissions decal on the rad support just like. Do not forget to add anti-seize to the threads only on the spark plug, start in the hole. You could use a piece of vacuum hose over the end of the plug to get it started in the hole.

Step Seven - Make sure that the plugs are tightened. Next, you will need to put everything back together in reverse order and apply some dielectric grease to the plug boots as well to help seal them.