How to Replace Spark Plugs 2001-10 Toyota Highlander

Hi, I’m Mike from 1A Auto. We’ve been selling auto parts for over 30 years!

Open the hood, we have to pull the release inside the car. It's just inside, right around your left knee on the driver's side. You need to release the secondary or safety release. Just feel around for it. This one is right here, squeeze up. Going to remove these two top nuts that hold on the appearance cover. They are 10 millimeter, so I'm using a 10 millimeter socket, ratchet and extension. They should just thread off real easily. Here's our appearance cover. It's got some foam inside that's just for noise. Just keeps the noise down from the valve train.

Here are your four coil packs. One for each cylinder. They're held into the valve cover with a 10 millimeter bolt. One for each. Underneath these is your spark plugs. Once these are removed, you can change your spark plugs and then reinstall the coil pack. Push down on the lock and remove the connector. These can be brittle. Sometimes they break, the lock does. This procedure will be the same for the other three. Use a ratchet, extension, and 10 millimeter socket to remove this 10 millimeter bolt. Put this bolt aside.

Now, I need to move the coil. May have to wiggle it because there is a seal in here and just break it free. As it's free, it should come right up. There's our coil pack. Use this special spark plug socket. It's got a rubber O-ring in there to hold the spark plug as we move it from the engine. This is one is a 5/8. Put on our extension, longer ratchet. Feed it down in there, you'll feel it sit onto spark plug. Break it free. Should take the ratchet off once it gets loose, just spin it out. You actually see this spark plug is covered with oil because our valve cover gasket has been leaking. Going to replace this spark plug after I clean up the spark plug openings, and then we'll replace the valve cover gasket.

This original spark plug. See it is all worn out. The brand new one we have from 1aauto.com is nice and fresh. The gap is small. Once we put all four of these in the vehicle, the car will be tuned up and it'll run great. I'm just going to take a rag and just carefully down here. Soak up as much as the oil as I can. I'm not going to worry about it too, too much. Any oil that make it into the cylinder will just get burned up anyways, but I do want to dry it up as much as I can before putting in the new spark plug.

Took our new spark plug, it's no need to gap this. It's pre-gapped. Put it into the socket. See it's held in with that rubber piece, so you can put it in without it falling out and take it by hand. You find the threads, put in it in by hand first, make sure it doesn't cross thread. That's just starting to touch the gasket. Take a torque wrench, set to 14 foot-pounds and tighten this down. All you're doing is crushing the crush gasket, so right there the spark plug is torqued in place. Sometimes that happens, the socket will stay on the plug, and you just kind of wiggle it a little bit.

Spark plug sockets have quite a grip to them. Sometimes if you don't have an extension that fits perfect into the socket, it can get stuck, so you just wiggle it around and break it free. It'll come right out. Just repeat these steps for the other three spark plugs and coils. Reinstall the coil, we'll line up the opening with the mounting hole. Move the harness out of the way, so I won't get pinched. We'll push right over the spark plug, reinstall the bolt. Once it gets tight, I'm just going to stop. Put the connector back in.

Now, we're going to reinstall the plastic engine cover. Wiped it down with a rag to clean some of the dirt off of it, make it look a little nicer. Get it lined up over those studs. It'll sit right down, reinstall the nuts. Actually, just do these hand tight. They don't need to be super tight. Job is complete.

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