View Single Post
930gt-40r 930gt-40r is offline
Registered User
930gt-40r's Avatar
Join Date: Jan 2007
Location: Boca Raton, FL
Posts: 2,063
Leak-down results after blow up

Long and the short- I popped my motor this weekend after whacking the rev-limiter to hard. Went home did, a compression test, didnt like what I saw, pulled the motor, did cold leak down, found bent valves, tore off heads, and now a real *****ty problem. I blew off two rockers and bent the exhaust valves on 1-3, cylinders 4-6 were fine (All had 3% Leak-down). When I did the leak down I felt like there was more air coming through the breather on 1-3- so in turn I took the good heads from 4-6 and tried them on cylinders 1-3. Heres the fun part- 1-3 with the good heads still had bad and inconsistant leakage numbers. Took the heads back off along with the cylinder from #3. I looked and looked and looked, tried puring oil into the cylinder and re-trying the leakdown and still got a bad number and the rings were perfect. Now I think I have a cracked piston/s, Before I go and blow my head off I would like to know if anyone has any ideas as to what the problem could be and/or maybe a solution.

Oh and by the way- all of the chain ramps on 1-3 were broke- I pretty sure that I had a bad tensioner from the looks of it. This should have been the cause of the problem.
Kris @ Tech9
86' 930/GT-40R Sold
94' Rustang GT daily (long gone)
2008 C6/Z51 Corvette
Old 05-08-2008, 03:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)