Spark Plug Install Instructions

What I put in: NGK Iridium IX (LFR7AIX) one step colder plugs.


Tools you will need:

10mm socket or ratchet - to remove intake and battery.

12mm socket to remove coil pack bolts.

1/4 drive socket wrench with 12mm socket for the two rear coil packs (It's tight).

5/8" spark plug socket

2", 3" and 12" extension for 3/8 drive wrench - For removing the spark plugs and coil pack bolts.

A knuckle extension.

Anti seize - I use this on the spark plug threads

Dilectric grease - I put a dab on the top of the spark plug where the coil packs wire touches the plug


Do the spark plug change when the motor is cold so you don't risk striping something or burn the living daylights out of yourself.


First start by removing the air box and all of it's plumming up to the inlet hose. First start by undoing the hose clamp that connects the airbox rubber hose to the inlet with a screw driver. The unsnap the air box clamshell clips and pull the back half of the airbox out of the engine bay. Now with a long extension remove the two 10mm bolts that hold the airbox to the fender. Don't forget the 1 10mm bolt inside the airbox as well.

Once the airbox is out go ahead and remove the battery tie down with the 10mm socket. Once that is out of the way remove the batt cables. Remember to undo the negative first and then the positive battery cable so you don't risk gettin a zap. (Installing will be positive and then negative).

Getting the airbox and battery out will make for alot more room as things are tight as is. Doing the WRX/STI some will take out the window washer bottle, but that is not needed for the LGT.

Passanger Side (Pic 1)


Getting the coil pack off of the spark plug isn't all that hard for the two on each side in the front of the motor. The gold bolts you see are the only things that hold the coil pack onto the motor. Using a 12mm socket and knuckle along with a 3 inch extention remove the bolts. The fronts are simple and you have plenty of room. The back coil packs it's tight. This is where the 1/4 drive comes into play. The engine bay tapers to the rear so it will take some patience for the rears. I found that if I got the bolt loose enough I could take the ratchet off and keep the 12mm socket on the bolt and loosen it by hand. Don't worry about the bolts coming out of the packs, they don't. The rear passanger side coil pack has a bracket attached to it for the EGT wires that run to the Uppipe (Pic 2). Once the bolt on that pack is loose the bracket will fall to the side. It's ok and is easily put back when the coil pack goes back on. To distinguish the front pack from the rear pack the wire harness that runs to each has a white and black adapter (Pic 3). The pack with the white adapters are the front and the rear is the black.

Drivers side:

The front coil is a piece of cake and is just as easy as the passanger side front. However, the driver side rear is a headache. The space is tight and the problem is not getting the 12mm bolts off, which is the same as the passanger side. The rear coil pack does not have alot of slack to it interms of the wires running to it. Ontop of that, it is extremely close to the fender wall and takes some work to get out (Pic 1). The previous three coil packs you are able to take out and draw them up. However, the driverside rear you have to place below the cylinder because it is too tight to pull it up.

Once you have the coil packs out of the way you are ready to remove the spark plugs. What I found to be the easiest for all four cylinders is to slide the 5/8 inch spark plug socket onto the spark plug first, and then the knuckle extention, the 12in extension and then the 3/8 ratchet. The spark plugs are deep so your gonna be thinking these things are never gonna get out. Be patient with the rears because you are at a very odd angle. The closer you can get to perpendicular with the cylinder the better you will be. Here is a side by side of the old and the new (Pic 1).

Before you start to install the new plugs when all the old ones are out, check the gaps between the two. I know the spark plugs come pregapped, but you don't wanna find out after you have them in that the gap is too large and your misfiring. Be careful when you check the gap to not damage the electrode (it is very delicate).

Before you install the new plugs, go ahead and put some anti-seize on the threads (you'll appreciate it if you ever need to pull them out again). You can use dilectric grease on the top of the plug that connets to the coil pack if you choose. Once the plug is prepared place it in the 5/8 spark plug socket. I have read that some take the cushion out of the socket, I don't find this to be a great idea because for the rears you are working with weird angles and risk cracking the plug should the socket slip off the plug. Connect the socket to a 2" extension as the cylinder is deep (Pic 1). Your going to wanna install the plugs by hand first as to not cross-thread the plug into the head. Again, doing this by hand for the rears takes patience. Once you plug threads into the head attach the knuckle extension and then the 3" extension followed by the 3/8 ratchet. Go ahead and tighten the plugs in.

Once all the plugs are in you can put the coil packs back on. Remember, the coil pack with the white harness is the front and the black the rear (Pic 2)Another thing to keep in mind when you install the packs back onto the plugs; you are not going to get the distinct snap that you would with a set of wires. With each pack you put on go ahead and slide the 12mm socket onto the gold bolt and hand tighten them first and then pop on the knuckle extension and 12in extension with 3/8 ratchet to tighten them down fully. Remember that the passanger side rear pack holds the EGT bracket, so before you tighten it down too far slide the bracket back onto the bolt and then tighten it down.

Once all the packs are on reinstall the air box and your battery. Go ahead and start her up! Don't forget to reset the clock, radio stations, and to shut off the annoying seatbelt chime.

Ok I'm done now....

Nice write-up!

we should move this to the Maintenance Walkthrough section, and objections?

Keefe

Question ? What does a Subaru dealer charge to do a plug change ?

Originally Posted by franklin

Question ? What does a Subaru dealer charge to do a plug change ?

Probably 2-3hr labor and the plugs.

Thanks. Sounds like 3hr. x $90.00 = $270.00 + Plugs ($40.00 ?)= $300.00+

Originally Posted by franklin

Thanks. Sounds like 3hr. x $90.00 = $270.00 + Plugs ($40.00 ?)= $300.00+

Thats about right.....it took me 1.5hrs. But Dealers tend to overestimate and let the car sit.

The plugs in the LGT are platinum and are only due to be changed every 60,000 miles.

We charge 2.2 hrs labor to change just the plugs, or if you change them along with a 60,000 mile service we charge only .5 hours labor (In addition to the 60,000 mile service charge).

Originally Posted by Opie

The plugs in the LGT are platinum and are only due to be changed every 60,000 miles.

We charge 2.2 hrs labor to change just the plugs, or if you change them along with a 60,000 mile service we charge only .5 hours labor (In addition to the 60,000 mile service charge).

I changed them for the one step colder. 2.2hrs? I took 1.5 with a few smoke breaks and to wash the Perrin air filter?

Nice write up. I vote for two gold stars for you..thanks

Originally Posted by Opie

The plugs in the LGT are platinum and are only due to be changed every 60,000 miles.

We charge 2.2 hrs labor to change just the plugs, or if you change them along with a 60,000 mile service we charge only .5 hours labor (In addition to the 60,000 mile service charge).

Ive been told that the stock plugs in our Turbos are Iridium not Platinum.