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View Full Version : Misfires and piston ring blow by related?

pjk91
09-04-2009, 04:26 PM
This is not a Subaru but likely anyone with some engine expertise would be able to answer this question.

Oil on spark plugs is the result of piston ring blow by, correct?

I did a scan on the car today and I got these misfire history readings:

Cyl1# 5
Cyl2# 442
Cyl3# 150
Cyl4# 17

At what point should I be concerned for the longetivity of my motor? Pistons/rods were always in the plans anyways. High compression (10.4:1) + boost (9lbs).

If someone were to strip the threads of the head while putting in spark plugs, how would one fix this problem? I can never get the in-boost afr's to match up with what I'm commanding. I think all these problems are related.

Opinions?
Bu11dogg2
09-04-2009, 04:33 PM
depends in the motor, but it could be the plug sleeves. They are subjectable to corrosion just like any other part.

check them for corrosion, also check the plug wires or coil packs (depends on year and make) replace if you find oil in the plug wire tubes.

A little blow by is fine, left unchecked it can be bad....
kgj996
09-04-2009, 04:45 PM
If you have a stripped out plug socket you can always install a helicoil. I think you can buy an install kit for under $50 at autozone or pepboys.
pjk91
09-05-2009, 09:47 AM
i've swapped coil packs around and got the same results. plugs are good. the wires are good too. it's a 2007 with 58k.
Bu11dogg2
09-08-2009, 09:04 PM
Figure it out?
Robk0000
09-08-2009, 09:31 PM
I think pat's coming back up to nh for a while so i will bother him about it. lol
Bu11dogg2
09-12-2009, 12:50 PM
bump
Robk0000
09-13-2009, 01:46 PM
He Aint too bright, so dont rush him. :)











http://media1.break.com/dnet/media/2008/3/08mar26-he-aint-too-bright.jpg (http://www.break.com/pictures/jet-pool477261.html)
kgj996
09-13-2009, 05:36 PM
What injectors are you running? A clogged or bad injector could be the cause.
Nick S.
09-13-2009, 09:19 PM
Why don't you start with a compression test followed by a leak down test if you get a low compression reading. This will let you know if you have blow by or just some leaky valve seals.
Bu11dogg2
09-21-2009, 10:57 AM
bump
Seraphinwolf
09-21-2009, 02:28 PM
Shouldn't this be in the drivetrain section not powertrain? Not to be a pric, just pointing out.