Spark Plug Install Instructions

Ahhh,..

 

whatever happened to my DSM where the plugs sat inside the head and were easily changed from above and took like 10 minutes to do?,..

 

Sheesh,..sounds just as frustrating as changing the plugs on my 2.5l 4cylinder Ford Ranger,...bad angles, scraped knuckles, some swearing, blood, sweat, tears,..;0

This is yet another reason EVOs make so much power with so little money. Compare changing their two cams in a couple hours and a few hundred bucks with changing our four cams in a day or two and around a thousand dollars.

This is yet another reason EVOs make so much power with so little money. Compare changing their two cams in a couple hours and a few hundred bucks with changing our four cams in a day or two and around a thousand dollars.

Maybe so.....but who'd want one??

would this be any easier from under the car? ie if it were on a lift

Well Yes it would, because the car would be able to be lifted so that you need not bend over so much. But you would still be accessing them from up top.

Well Yes it would, because the car would be able to be lifted so that you need not bend over so much. But you would still be accessing them from up top.

I don't see that it would really benefit that much. I changed mine in driveway. Broke 3/8" knuckle, but besides that it wasn't too awfully bad. The one on driver's side closest to firewall was the hardest. Have to work it a bit to get out, then same to get back in. I rolled it upside down and worked it out that way.

I don't see that it would really benefit that much. I changed mine in driveway. Broke 3/8" knuckle, but besides that it wasn't too awfully bad. The one on driver's side closest to firewall was the hardest. Have to work it a bit to get out, then same to get back in. I rolled it upside down and worked it out that way.

It would have helped me taking it apart multiple times to chase down what turned out to be a bad coil... My back was sore the next morning, from being bent over, and r&r the battery a few times too!

I wouldn't pay for use of a lift, but if one was available, as always, it does make it a little easier.

It would have helped me taking it apart multiple times to chase down what turned out to be a bad coil... My back was sore the next morning, from being bent over, and r&r the battery a few times too!

 

I wouldn't pay for use of a lift, but if one was available, as always, it does make it a little easier.

Or course every jobs gonna be a bit different, eh?

The mainenance schedule says to change the plugs at 30k right?

The mysubaru.com page says 30k. I don't know where they got that. From the 2.5i?

So, is it necessary to go to the one-step colder plugs if you are stage 2 ???

It's idea to go to one-step colder's when running more boost. It's just gooder. Keep readin', they are many good things about changin' to a colder plug.

http://www.putfile.com/tundwgn

AP TDC Pro Tune Stage 2 Map, Crucial Racing Uppipe, Stromung DP, Unorthodox Racing Pulleys, Crucial Racing 160* T-stat, K&N Air Filter, Piaa FR-S Wheels, Nitto Neo-Gens. My list is slowly growing!!

I just did mine....

my two cents worth of tips:

the passenger side was a breeze after the airbox was removed, so I won't comment on that.

but for the driver side, the thick wire harness from the fuse box near the battery can be unclipped from the C-clip that holds it above the front coil pack. then you can push it toward the motor and tuck it under the eng cover for more access (especially to the rear pack/plug)

on the driver rear pack, unclip the driver front coil pack wire harness and tuck it away towards the firewall (rear of the engine). then, once you have the rear coil pack bolt loosened all the way, rotate the coil pack 180 degrees. the wire harness plug should be now easily removable. Also, with the pack rotated like that, it wiggles out completely from the top with no issues. just be sure to put it back in the same way you take it out. I was also able to do mine without removing the battery. and the tools listed are def necessary.

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.

Good write up.

For installing the plugs, I've found that you can create your own flex extension by using a rubber hose that fits over the end of the spark plug. I use this to thread and seat the spark plug gently. Works surprisingly well.

Excellent Walk-Through, brother BoxerGT2.5 - thanks a bunch!

I'm embarrassed to say that it took me about 2 and 1/2 hours to do just the driver's bank (my chosen "first set").....

I kept making small mistakes "spacially." It sure is tight down there!

The passenger's side took me only a half-hour. Much more respectable.

Thanks again for a great Walk-Through.

The service manual says 60k. I think the owners manual says 60k.

 

The mysubaru.com page says 30k. I don't know where they got that. From the 2.5i?

Yes, 2.5i @ 30K, just did mine a couple of weeks ago. no problems at all.

OT: damn those are some expensive plugs.

Its amazing how much easier the WRX was to change the plugs on than the legacy. The engine sits so slow next to the wheel wells.

I actually find it easier to use a spring back universal joint on a 3/4" socket. This should fit over the end of all 5/8" plug sockets. It just makes it easier to get on and off in the tight quarters. Also, remove the little rubber plug holder that sits inside the plug socket. It took me a half hour to get the socket off the plug because of this.

A few tips:

- When replacing the rear plugs, getting the coils out of the way may seem impossible, unless you unplug it from the wire harness and turn it upside down 180deg then try removing it.

- When removing the nut on the passenger-side rear coil, you have to use an offset wrench, low-profile ratchet/socket or 12mm univ-socket. The space is tight back there.

- When unscrewing the plugs, some may take much more effort than you think is needed. When I did mine, 3 of them I could finish unscrewing with my hands but 1 was tight until the last thread that I thought it was cross-threaded, but it does not look like it is. I was able to screw it back in with no problem but still took way more effort, more than the 15ftlbs of torque, than I felt comfortable. Since my dealer was the only one that touched the plugs before I started doing my own. I took to them and they stated that sometimes the plug threads may be dirty and therefore screwing them in may take some effort. I tried to again to make sure and it screws in and out but still with a lot of effort.

- After screwing in the plugs and when putting the coils back on, make sure that the coils are flush against the head. If there is any in/out play or spring-action from pressing on the coils, then plugs are not all the way in. Again I learned this the hard way, when I stopped screwing in my final plug too early since it was taking a lot of effort.

- You do not have to use anti-sieze. The Subaru vacation pix only suggest using motor oil on the threads and in doing so make sure to only apply 1/3 of the specified torque when screwing them in.

- When removing the intake, it is gonna make it easier if you remove the flexible intake connector first.

For me, the minimum required tools were:

- Extendable magnetic wand and tray (Life savers)

- 10mm 3/8 drive with at least a 10inch extension for the intake

- 10mm wrench for the bolt holding the intake

- 12mm 1/4 drive and 12mm offset wrench for the coils

- spark plug socket + univ joint + >=4 inch extension 3/8 drive to unscrew plugs

- Pliers to pull spark plug socket off plug after screwing back in

....When replacing the rear plugs, getting the coils out of the way may seem impossible, unless you unplug it from the wire harness and turn it upside down 180deg then try removing it....

 

good advice....guess you didn't read my tips in post #41 before doing the work

^^ Great tips. I am summoning the courage to change mine this weekend.

^ Best of luck, bruddah!

good advice....guess you didn't read my tips in post #41 before doing the work

DAMN IT.

I printed this whole thread and read your post before starting, but I still missed it. :icon_mad: