Changed 74k mile spark plugs from 3.5 EcoBoost today

SubieRubyRoo

SubieRubyRoo

Joined
May 15, 2012
Messages
9,011
Location
The land of USA-made Subies!
Well, finally got around to it. Had great weather- low 70s and overcast so it was very pleasant. First time other than oil changes that I’ve had to touch anything other than adding the S&B intake. Realistically, I probably could have left them in with how good they look. Yes, AFAIK these are the plugs the truck rolled off the line in mid 2019 with; I got it with 23k and I’ve never changed them. Plugs are arranged outer to inner from back to front, side respective. Thoughts?

I’d say probably 40k of my 50k has been run with 5 Star Tuning’s 87 Perf-Tow tune, and probably 8-9k with the E30, ~510rwhp tune. I think they held up well, considering the truck frequently sees E15, and obviously E30 for about 11% of the time.

Replaced with NGK Ruthenium HXs.

IMG_2218.jpeg
IMG_2221.jpeg
IMG_2222.jpeg
 
Last edited by a moderator:
Brian123 said:
Looks Good 2 Me!
Click to expand...
Yeah I read all these worrywarts changing plugs every 30k on EcoBoosts, and I’m not quite sure why. These plugs ran double plus half that amount, and honestly look like they could easily go another 30k. All the gaps are still nice and even, no erosion, and surprisingly (thank heavens!) no aluminum speckling or any debris on the insulator. If I had known they looked this good, I may have left them for a winter project 🤣
 
CKN said:
The vast consensus is to use OEM plugs when replacing.
Click to expand...
Yeah, I’ll see how they do. I had gotten the Ruthenium’s obviously for the longevity aspect, but with the OEMs lasting like they did I’d have no real issues pulling these out if they have a negative mileage or drivability impact. 👍🏻
 
SubieRubyRoo said:
Yeah I read all these worrywarts changing plugs every 30k on EcoBoosts, and I’m not quite sure why.
Click to expand...
On the early 3.5 EB's the spark would blow out and terrible misfire was the result, not to mention the occasional slug of water from the intercooler during humid conditions (for those who never drilled a drain hole). New plugs solved the problem dry misfire problem.
 
CKN said:
Two thoughts-
The plugs probably could have gone another 30,000 easily- if not more.
The vast consensus is to use OEM plugs when replacing.
Click to expand...
I would imagine that those OE plugs are made by NGK so I doubt installing 'Rutheniums' by NGK would cause issues. In a V6 with hard to reach rear plugs I'd do the same.
 
Kira- no, the threads were completely dry and you could see there was no anti-seize installed on the assembly line. There were a couple tiny spots where the plugs squeaked, but literally after breaking the torque loose I was able to spin 95% of the plug out with just the extension in my fingers.
 
OE plugs look excellent for the mileage, E30 really helps with combustion efficiency. Ruths are a dynamite plug and will last a loooooong time too. Ones in my cars hardly look used at all after 60K (they went back in). Probably a bit cheaper than OEMs knowing how just putting a logo on something will double the price. Those OEs also look to have a coating similar to NGK's trivalent one that precludes the need for any anti-seize. Mine were quiet on removal with aluminum heads.
 
Shorty- that seems logical. After breaking the plug loose, the squeaks were all in the first 60-90* of spinning the plugs loose, really almost none after the plugs were off the seat.
 
You must log in or register to reply here.

Similar threads

C
  • Locked
1995 Chevy C1500 spark plug change
Replies
13
Views
4K
clinebarger
y_p_w
  • Locked
2001 Civic LX spark plug change - 65K miles
Replies
18
Views
12K
y_p_w
Back
Top