Via Compression Test... How can you tell if your VALVE is cracked/blown or you blew a hole in your PISTON?
I dont hear clanking. Not a ROD I'm guessing. I hear a obvious missing. Like not firing on all 6 cyl's type missing.
Compression tested her. Cyl.3 showing its gone. She doesn't clank tho.
Whats the likelihood it being a piston or valve in a turbo application(Grand National, 3.8l V6 Turbo)?
Will the cyl. walls need resurface? If so I would need to bore-over, correct?
2007-09-16 09:50:52 · 3 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
add about 1/2 oz of oil into #3. then spin it again. if the compression bumps more than 10 psi look at the bottom end. if it stays the same bank on top end. i do think that the exhaust valve is prob the culprit though.
2007-09-16 10:15:23 · answer #1 · answered by chevy_man_rob 5 · 0⤊ 0⤋
Nine times out of ten it's a burnt exhaust valve. You usually just have to replace the valve and regrind the valve seat.
Any time you pull a head you should grind or at least reseat the valves (lapping compound) on all the valves. Don't mix 'em up.
If one valve is burnt then others may not be far behind. Relatively easy fix but takes patience and time.
Good Luck!
2007-09-16 17:04:24 · answer #2 · answered by CactiJoe 7 · 0⤊ 0⤋
Stuck, or damaged exhaust valve, or valve seat came loose, broken valve spring?
Do a leak down test to determine where the leak is.
2007-09-16 17:12:48 · answer #3 · answered by Mr. KnowItAll 7 · 0⤊ 0⤋