Dry compression test was 60 psi, wet was 75. Did a leak down and air came out the valve cover. It’s only cyl5 fortunately. How expensive/difficult will it be to replace the rings? (if it’s not cylinder walls)? Would like to diy if possible.
fried piston rings
- Thread starter withku
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yaycandy
Aerospace Engineer
Shove a camera in the hole.
Wth, you NEED to hone cylinder when replacing rings too
Wth, you NEED to hone cylinder when replacing rings too
Ah should of known that. So time for a rebuild then.
yaycandy
Aerospace Engineer
Buy a new or used engine. Amount of time and money spent wont out do just getting a new engine and huckin it in. If walls are bad it will need bored, then you need to bore them all. Well you dont need to, i rebuilt an engine with .03 overbore on one cylinder. It ran but shook alot. Still running to this day.
Best to tear engine completely down.
Also whats the reason for fried rings? Did you run e85 like me? If cylinder gets hot the ring expands and the joints run into each other and score up the walls and trash the cylinder walls.
No clue why they went. Never overheated, ran 91. I use royal purple full synthetic and oem filters.
yaycandy
Aerospace Engineer
You sure its a not sealing intake valve? Also common from carbon buildup. Happened to me on my new engine also. Run a can or 2 of crc intake valve and turbo cleaner
Tried that, no change. Strangely enough I just got a rough idle, it has good power still
yaycandy
Aerospace Engineer
I fried cylinder 2 on my old engine. Rough idle, poor acceleration up to about 30mph then the turbos kick in “ add compression” and it was just as fast over 30mph
FiveLeeter918
Ortiz Performance Sales
Add a cap full of oil to the cylinder, rotate the engine by hand, and check compression again. If compression bumps up, then yea it's definitely a ring. IF it doesn't change, you have something else going on.
Like yaycandy suggested, I'd scope it before dumping more money into it.
Like yaycandy suggested, I'd scope it before dumping more money into it.
Ta2dResqr
SHO Member
I'm with the scope idea. You already did a wet test and only gained 15 psi. I'd be concerned about valves or a hole in the piston. A leak down test would help a lot. That would let you know where the leak is going (coolant/oil - head gasket, intake/exhaust - valve, crankcase - cylinder walls/piston/rings)
compression jumped 15 psi, definitely rings. i’ll try scope the piston
already did a leak down, came out the valve cover
Ta2dResqr
SHO Member
Are 4 and 6 at 130-243 psi? Any oil consumption issues? 15 psi is not a big jump for a wet test. I'd expect closer to 40 if it was a ring issue.
yaycandy
Aerospace Engineer
You need to scope the cylinder walls also. Here is what the inside of my cylinder looked like when i thought it was just the rings.
Well they’ve been extra wet for a while due to bad pcv. i’ll test 4 and 6 again.
I feel like wet compression tests are great for confirming worn rings but is ineffective at ruling out a broken ring or cracked ring land. On the other hand, a leakdown test that results in air blasting out the dipstick tube tells a pretty definitive story. I also think what is simply excessive ****-by is being falsely labeled and dismissed as a bad PCV. OP has been spreading his saga across 3 or 4 threads, putting in maximum effort to make sure nobody can follow what has or hasn't been tried already.
I’ve made a few posts yeah. They don’t always gain traction and I need the help, i’m a high school student haha
4 and 6 are 160 psi. I also noticed my plug well on 5 is stained brownish, the rest are perfectly clean. Side effect of misfire? or could i have been leaking out my plug?
The word b l o w is censored? Holy cow!
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