Spark Plug Install Instructions

I just did mine. I found for extensions the best that worked for me was the 5/8" plug socket, 3/8"m to 1/2"f adapter, 1/2 u-joint and then adapted back to 3/8" for the long extension and ratchet. THis allowed me to fit the socket down in the chamber and allowed enough clearance that I barely thought about engine bay. Took 3 hours of non-dedicated work. Having done it i'd be confident next time to be done in an hour

I just looked up the plug recommendation at the NKG web site for my 2005 LGT. For original temp range plugs, NKG says the SILFR6A plug is designed to last 80 to 100k and the LFR6AIX are designed to last 40- 50k.

 

http://www.ngksparkplugs.com/pdf/DYK_LaserIridium_vs_Iridium%20IX.pdf

 

john

I just did mine. I found for extensions the best that worked for me was the 5/8" plug socket, 3/8"m to 1/2"f adapter, 1/2 u-joint and then adapted back to 3/8" for the long extension and ratchet. THis allowed me to fit the socket down in the chamber and allowed enough clearance that I barely thought about engine bay. Took 3 hours of non-dedicated work. Having done it i'd be confident next time to be done in an hour

 

Thanks..this worked perfect for me! Took me just under 2 hours at a slow pace.

 

One of the coil packs was a little more rusted than the rest... Wonder how much life it has left. http://img.tapatalk.com/d/13/10/28/yrudu5yv.jpghttp://img.tapatalk.com/d/13/10/28/5usa8ehy.jpg

 

 

-Greg

Driver's side rear CP?

Driver's side rear CP?

 

Yep. Hated putting back in, thinking I might have to pull it back out again soon. Car only has 55k miles. I'm guessing this is a common prob?

 

 

-Greg

Not so much a common problem, it's the most exposed plug of the four, so our Northern brethren and sistren, typically have this issue. I bought a set of T-O's from another member (from PA) and was surprised by the amount of corrosion on the one CP. When I applied light wire dremel to it, it cleaned-up and I liberally coated it in protectant before putting them away in the spare parts locker.

 

Do you run your plastic lower engine cover and the plastic side covers? That helps, but it's not complete protection for it.

Do you run your plastic lower engine cover and the plastic side covers? That helps, but it's not complete protection for it.

 

I do run the covers :/

 

 

-Greg

Well that was fun (not really) but it seems I was successful. Thanks to all who posted.

 

I put about 5 hours into changing the plugs, including eating, cussing, and finding my tools littered around the garage. Same story for me: passenger side was a breeze, driver side front was painful but managable, driver rear was a nightmare until I found the secret. My highlights:

 

1. I couldn't get the air tube that obstructs the driver's side coil packs out of the way enough until I loosened the two bolts holding the air pump. Once I did that, I disconnected the front of the air tube and was able to pivot it out of the way, mostly.

2. Driver's side rear coil pack baffled me until I read on here to "rotate it." I thought I'd rotated it every way possible, but as a video early in this thread illustrated (and which I found after I figured it out, doh!), rotate the coil pack to upside down. Then it clears the frame just fine.

 

I've worked on a lot of cars, including a 2002 WRX. This was more frustrating and irritating than anything else I've done, including up pipe, down pipe, turbo and injectors in the WRX. But I'm done...and won't need to worry about it for about 30K miles! Now to put antiseptic on my wounds.

So of the two "One Step Colder" plugs mentioned in this thread:

NGK SILFR7A

NGK LFR7AIX

Which ones are better for running higher boost levels up to 20lbs?

 

Thanks,

Rob

 

Also, at what interval should the coil packs be changed?

I think you'd be fine with OEM.

 

I wouldn't change the coil packs until an issue.

So of the two "One Step Colder" plugs mentioned in this thread:

NGK SILFR7A

NGK LFR7AIX

Which ones are better for running higher boost levels up to 20lbs?

 

Thanks,

Rob

 

Also, at what interval should the coil packs be changed?

 

 

I would go with the SILFR7A's. I run one step colder plugs in my wagon, have for years.

 

#4 cylinder is the one with the most issues. But a bad coil there will not be a big issue. To me it's more of, how much is a replacement coil ? how hard it it to replace ? with winter coming, when do you think it might fail ? Jan or Feb ? or the coldest day of winter...?

 

My 05 has the original coils, it my DD.

I'll be tackling this tomorrow. Can't wait.

 

Ok, job is done. It took me about an hour and 45 minutes. It wasn't too bad with the exception of the passenger side rear plug. Even with all of my extensions and adapters, I couldn't get the 3/8" drive in there very well. That's right, I did the whole job without the use of a 1/4" drive. The only other problem I had was trying to fit the coil/boot back over the plug on the driver's side rear. It seemed no amount of playing with it could get the plug boot to go over the top of the plug. Eventually I pulled the sound deadening material away and was able to finally get it to slide over the top.

 

As for my old original plugs? They looked really good after 60,557 miles. I think the previous owner drove the car very easy for the 41k miles they owned it. The car runs exactly the same now as it did with the old plugs, which is good I guess. Also, there was no rust at all anywhere on the coils. I bought the car in Albuquerque, NM though which is a pretty dry climate so that's probably why.

Edited December 23, 2013 by kbohip

Just got done with the Spark plug job:

 

I bought the tool seen in earlier messages in this thread from Harbor Freight:

1/4" And 3/8" Drive X 14-3/8" Double Head Flex Ratchet Wrench

Item #67994

This tool made the job painless.

The only other tools I needed for this job were the 5/8" spark plug socket, a 12mm socket, and a 3" extension.

The driver's side rear coil took a bit of adjusting like a puzzle but no real problem.

Took about 40 minutes per side. No scrapes, not a hard job.

Far better job than replacing my oil pickup in the oil pan...that was a bitch to get that oil pan back in there- never seen bolts as hidden as those rear oil pain bolts.

I tackled this job today, and ended up having the #4 coil pack plug snap off the lock-clip (part on the harness). Got everything all back together, plugged in the coil pack and gave the harness a light tug to check the plug was fully seated and the lock was in place. Locking tab snapped off.

 

Are these available somewhere as a replacement part? Dealership or some other place? I'm hoping that just the clip housing is available (and its not just 'included' in the engine harness...) - I have the means to swap the wires out, just need the plug.

 

Other than the locking tab, the plug is still operational (I have it zip-tied securely in place until I can fix it properly)

 

Part number would be beneficial if anyone has it - the broken plug is one of the black ones.

 

thx

I remember doing the spark plug job a few years back around 60k miles. Now at 125k miles and I recently moved no garage available and its winter so I had my favorite local subaru shop do the spark plugs. Labor only (I had subaru plugs) was $177 (1.5 hours bill time) even though the subaru book lists 2.2 hours.

 

I can't remember how long it took me last time... it was my first Subaru spark plug job so I assume I was in the garage off and on for a good part of the day.

 

$177 is a lot of money but after hearing some of the horror stories in this thread again I don't feel bad about spending the money to have it done quickly and correctly and now I have the entire weekend to get other stuff done.

 

Oh, and after this weekend I'll post any improvement in gas mileage. It hasn't been impressive, but if it improves significantly with new plugs I will be happily surprised.

Edited February 14, 2014 by 2006Specb122
add on small note

... $177 (1.5 hours bill time) ...

 

$177 is a lot of money but after hearing some of the horror stories ...

 

Speaking for myself, the horror was when doing it on my old 1997. It's WAY easier on my 2006, simply because the location of the sparkplug wells is an inch or two higher with respect to the frame members that run through there.

 

$177 for 1.5 hours though, geez ! And you know the mechanic ain't even getting half of that.

1 Edited February 25, 2014 by giogio43

To ease the pain simply raise the engine, it takes about 10 mins more of your time. Remove pitch stopper, two lower mount nuts and use a piece of wood and jack. Extra 3" goes a looong way Oh and the DP connector tab to the gearbox. Edited April 24, 2014 by GEE-OTTO

Don't overstress your trans mount by tipping the motor up too much. Pitch stopper plus about an inch.

This is a little different approach. I blew a turbo and was replacing with a BNR 16g but before before so, I wanted to do a compression test. Rather than doing the change from above, we did the change from below but there is still very little room. We ended up uping the car up on jack putting a hoist on the engine after the intercooler was removed. Removed one bolt of the dog bone thing up on top of the engine. Removed the 2 bolts for the engine on one side and slowly let the engine down about 2 inches. From there the coils are nearly exposed and you just take them out and do your compression test. Then raise the engine back up bolt it up and do the other side. It still took 4 hours the first time but that was only because we were figuring it out.

 

As it turns out, after everything is put back together (including turbo. dp, up), my etuner notes that there is knocking at mid pull and questions the spark plugs I replaced. There were the infamous NGK -11. I did not regap them to 0.030. So we ended up doing it again 2 weeks after the first time. It still took 1.5 hours but I rather work in a space that I can get into rather than a small space where where I frustration levels would probably blow a head gasket on me. Hat off to those who can do it. Just another perspective. And don't forget to check the gap but only lightly.

 

Is the OBXT any different than the LGT. Sure looked like a lot more space on the video of the rear diver side. Maybe just my imagination and dreading trying to get that coil pack out.

OBXT engine sits lower in the chassis than the LGT.

I may have said this before, get two 5/8 spark plug sockets. pull the rubber piece out of one of them.

 

Use the one with the rubber to install the plug about half way in the threads, then remove that socket and put the one on that has no rubber in it. Finish torquing the plug with it.

 

SBT, Is that true, the OBXT engines sit lower inthe frame ? I find that hard to believe, aren't these the same chassis ? I thought the only major difference was OB's had frame spacers that gave it more ground clearance.

Max - There's several pieces that suspend the OB engine/drivetrain lower in the chassis, including the motor mounts and the transmission mounts. Wasn't aware of this until BAC5.2 , IIRC, mentioned it. Then did some research on it and yes, it sits lower. It's also the reason the OB folks were having issues with their TMIC sitting lower relative to their clutch MC. Subaru had to do something to recapture the lower Legacy drivetrain COG, given the higher platform of the OB.

Thanks, I wonder what BAC5.2 is up to lately, I do miss him. May be I'll try and PM him.

One thing to note for those that may be doing the plugs well past their due date have a set of picks on hand in case the ceramic part of the plug cracks up. You will need them to pick out the debris in order to get the plug socket seated properly on the plug.