Plugs are very stiff/tight to remove.

[uniberp]

I pretty much solved the last of the drivability issues with the Legato by replacing plugs (and plug wires).

 

I didn't seen anybody mention how tight the plugs would be. I was afraid they were fused in and I was damaging something by unscrewing them. I stopped, sprayed some pblaster and though about the possibility of messing up an otherwise OK running car.

 

They all unscrewed equally hard (like 30 ft lbs, by feel) , and gapped at .050. So they've been in there a while. Someone here posted an NGK mileage/wear chart I wish I could find. I put anti-sieze on the new NGK's and installed them. It ran lots better.

 

Also, there seems to be a mid-year plug wire change for the 97. An NGK set I ordered had male 'coil' ends and no 90 degree cap on 2. The local parts store guy found a set by a crosscheck , with femail ends AND the 90 cap, so I bought them. FWIW, the wires seemed to make no difference. The plugs made all the difference.

 

mpergielelmhurstil97legato99forester

[WoodsWagon]

Plugs can sometimes be hard to remove if the ring gasket/washer gets stuck to the head and the plug has to thread out through it. Did you look at each of the old plugs to see if the washer was on each of them? If you left the washers behind, you could have double-stacked them when you put the new plugs in.

 

If the washers are stuck, a long thin flat head screwdriver is the tool to use. Slip it in next to the washer and give it a twist, the washer will usually pop off.

[rude]

My plugs were not real tight, after being in there for 100k, factory installed ~7 years ago. Put the new ones in around 15 in-lbs.

 

FYI:

NGK website “how do I read a spark plug” normal wear in a four stroke is 0.00063~0.000126 inches/1,000 miles, so for 100,000 that would be 63 to 13 mils. I suspect I got 30 to 40 mils of wear, depending on what they started at.

[uniberp]

My plugs were not real tight, after being in there for 100k, factory installed ~7 years ago. Put the new ones in around 15 in-lbs.

 

FYI:

NGK website “how do I read a spark plug” normal wear in a four stroke is 0.00063~0.000126 inches/1,000 miles, so for 100,000 that would be 63 to 13 mils. I suspect I got 30 to 40 mils of wear, depending on what they started at.

I suspect they were in a long time. 145K miles .015 wear puts it at the low end of the wear rate. (.050 measured minus .035 orig spec equals .015)

 

As to the tightness, I was half expecting something like a soft Beemer airhead plug, which will strip out if you speak harshly to it. Glad it's not. And washers were intact on all removed plugs.

 

BTW: Non OB Legacy 2.2 plugs are really easy to get at. Unsnap airbox and unbolt squirt reservoir.

Thanks

[The Dude]

I've noticed the same thing. The factory installed plugs can take a surprizing amount of force to remove. It almost feels like there is grit in the threads. I use plenty of anti-seize when installing replacements. Do as you wish, but I have found that a set of plugs is good for at least 60,000 miles in the 2.5L. In fact, the 2.5L DOHC was speced for 60,000 mile spark plug changes just because they were so difficult to get at.

[Rooster2]

I recently had the same problem, trying to remove really tight sparkplugs. Like others, I used a lot of PB Blaster, would wait for it to soak in, then try to remove. All came out with a lot of effort. I bought my OBW with 148K miles on the odo, so I have to think that I was replacing the original plugs.

 

Contrary to what others have written about replacing with NGK plugs, I went with Bosch Platinums with the single electrode. They seem to work just fine. Like others, I used antisieze on the new plug threads.

[rigfennid]

I just bought a 94 Legacy and don't have a manual. What is the gap spec for the plugs?

[porcupine73]

Hi rigfennid I have a '94 Legacy too.

 

Specifications

 

RECOMMENDED SPARK PLUGS

 

 

BRAND

--------------------------------- PART NO.

NGK BKR6E-11

NIPPONDENSO K20PR-U11

CHAMPION RC7YC-4

 

STANDARD GAP

0.039 - 0.043in (1.0 - 1.1mm)

 

SPARK PLUG TORQUE

13 - 17 ft lb (18 - 24Nm)

[rigfennid]

Thanks porcupine!!

 

I bought NGK's for her and I'll see how she does with that, but might get some wires too. Any recommendations on that?

 

I wanted a sedan but finding one that hasn't been ratted out is nearly impossible, so I got a wagon with 189,000 miles for $900! 5-speed & AWD too! Anything I should look for? I had a 97 but that was a 2.5 so the 2.2 is new to me.

[porcupine73]

but might get some wires too. Any recommendations on that?

Yes OEM wires from a Subaru dealer all the way.

 

You're not going to go wrong with the NGK plugs.