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How to change your sparkplugs

366K views 261 replies 97 participants last post by  Teawrecks 
#1 ·
Figured this might be helpful for somebody. First you'll need to properly gap your selected spark plugs- factory calls for .028-.031 gap, yours may vary depnding on model ie iridium or needs. Lots of info out there on choices of plugs- I won't go into any of it here.

You'll need to use some kind of gapping device and you'll want an accurate gap. Here's the tool I use:
 
#27 ·
A lot of guys are changing copper plugs at 3,000 miles. I tend to change things quite a bit earlier than most of the reccomended intervals- rotate tires every oil change, oil change at 3000 miles, swap tranny/diff fluid at 12,000, fuel filter 24,000, bleed brakes several times a year, change coolant every year, etc- then again my car is driven more spiritedly than most.
 
#28 ·
:( oh man i dont wanna spend more money on maintainance...
Im stock boosted now, but as soon as accessport comes... its looks like NGK platinum time

So is it cheaper to go get those special tools, or have a professional do it

Also, is there an advantage to copper plugs?

looks like ill need a fuel filter before i get accessport
 
#30 ·
Good tools are an investment. You'll save mucho $ over the long haul, the satisfaction of doing it yourself and you'll find nobody cares about your car like you do.

Copper plugs probably offer a little more spark when new, but they wear out quicker (cheaper too). Guys who are checking their plugs frequently run copper ones. I'm probably going back to a platinum plug.

Big Sky
 
#31 ·
thanks for the input guys... im stayin platinum, but will swap em out from now on @ 20k. I am staying on stock turbo, and will be pushing no more than 15psi...

Ive heard denso plugs are the best.. but my Dad's been using NGK in every car and truck, that hes ever owned... and they never seem to be down on power.
 
#32 ·
MidnightFLAT4 said:
thanks for the input guys... im stayin platinum, but will swap em out from now on @ 20k. I am staying on stock turbo, and will be pushing no more than 15psi...

Ive heard denso plugs are the best.. but my Dad's been using NGK in every car and truck, that hes ever owned... and they never seem to be down on power.
Densos are good, I used them on my Accord. I wouldn't recommend them for the WRX though as I have heard they break apart. Stick with the NGK's and you can't go wrong.
 
#33 ·
Big Sky WRX said:
A lot of guys are changing copper plugs at 3,000 miles. I tend to change things quite a bit earlier than most of the reccomended intervals- rotate tires every oil change, oil change at 3000 miles, swap tranny/diff fluid at 12,000, fuel filter 24,000, bleed brakes several times a year, change coolant every year, etc- then again my car is driven more spiritedly than most.
how much does a fuel filter cost and were exactly is it on a wrx?
Thanks,

dennis
 
#37 ·
replacing the boxer engine spark plugs are...

f..king pain in the ass...I just spent nearly 3 hrs chaning them. Not to mention my back is hurting like hell....will change them again after 30k miles. I put Platinum plugs to ensure long life as well as convenience(not chaning them too often).:D Anyway as usually thanks for the info. :)



WRXGOoooo
 
#40 ·
^^ this happened to me in my 3rd gen t/a; the #7 plug is a real pain to do. i thought i had it tight but one day driving down the highway i heard a pop and then thump thump thump. i actually thought it threw a rod or something, no smoke or anything and since it was my beater car i just kept on driving :D . later i found the plug had come out and welded itsself to the firewall. i got it in real good after that:wiggles:
 
#41 ·
Big Sky WRX said:
Reinstall all the pieces you have removed. Hooking up the battery last.

Check your spark plugs for unusual color- lot's of good sites explaining the different colors and conditions.

You have effectively reset your ECU by disconnecting your battery, which means the Advanced Multiplier (AM) is set back to 8, you want it to get to 16. You can do this quicly by gently driving (no boost) until you have a place you can get into 3rd gear- accelaerate slowly, left foot braking (puts load on) keep boost at ~ 2-3 psi for ~ 20-30 secs and it should be there. Ofcourse if you have a Delta Dash, you can tell for sure.

Happy driving.

Big Sky
Great help you are awesome!!!!!!
Could you explain more about the advance multiplier, what does it do, what if all of the drive in 3rd for 20 -30 secs is not done will it go back to 16?
 
#42 ·
#44 ·
THIS IS THE THREAD!!!!!!!!!!!! this is the one where i read you should use the flex sockets. it was such a PAIN IN THE ASS with those :unhappy: :unhappy: :unhappy: (btw i see i posted here above under my old username, allan r :D)

here's a better method: instead of using the dreaded flex sockets/adaptors, just place the socket on the bolt for the coil packs, connect the ratchet, and turn away. for the spark plug, attach your spark plug socket to a 3" extension, line it up on the plug and you will have just enough room to connect the ratchet. the whole job was DONE in 1/2 hour.

:)
 
#152 · (Edited)
That's what I did.

PLAC: I just changed my plugs tonight and they looked JUST like that. 66,000 miles and original. I took them to my brother-in-law who is a master mechanic and he said they looked normally worn with no red flag indicators.
 
#45 ·
yo vanilla said:
THIS IS THE THREAD!!!!!!!!!!!! this is the one where i read you should use the flex sockets. it was such a PAIN IN THE ASS with those :unhappy: :unhappy: :unhappy: (btw i see i posted here above under my old username, allan r :D)

here's a better method: instead of using the dreaded flex sockets/adaptors, just place the socket on the bolt for the coil packs, connect the ratchet, and turn away. for the spark plug, attach your spark plug socket to a 3" extension, line it up on the plug and you will have just enough room to connect the ratchet. the whole job was DONE in 1/2 hour.

:)
yeah, i did mine too but it took me 1/2 hour to figure out how to do it without flex sockets, but i must say it was pretty easy. Was done with it in 1 1/2 hour and i was doing it for the first time. The damn intake box is harder to asemle together than to change the spark plugs :thumbup:
But i must say this write up helped me a great deal. Thanx guys :wiggles: :wiggles: :wiggles: :wiggles: :wiggles:
 
#47 ·
Sotbas said:
When I took my car in for servicing once, they told me that they dont replace the spark plugs, they just clean them. What's the story with this?
What mileage? I believe the maintainence schedule calls for 60,000 mile change on the oe plugs. If it was your 60,000 mile service- I'd go back and point it out- the schedule should be in the back of the owner's manual.
 
#49 ·
don't be scared - its really easy if you have any experience with a ratchet. just take your time and if you have any concerns, analyze the situation before you do anything :)
 
#50 ·
Just did mine. It was fairly simple and straight forward. Just take your time, and double check everyting before you reassemble. The small bolts holding on the coil packs were as much a pain in the a@@ as anything else. It is really tight in there though and it helps to have small hands, and the right tools. Even as anal as I am about things, it was easily done in just over an hour. :cool:
 
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