01GPGT
11-08-2008, 06:54 AM
ok in school i am working on a fellow studants 1994 Impala SS with 50K on the clock.
the car has a dead cylander (#5) we check fuel and spark and it is fine has brand new plugs, wires, coil, and opti (it failed earlier)
we do a compretion test #1 had 182 PSI, #3 had 180 PSI, #5 had 40 PSI at this pont we stoped seeing as we found are problem (we did finish it later and the rest was fine)
we get the leak down tester take the vlave cover off get #5 to TDC by watching the rockers and a scew driver we put in the plug hole. we set the tester up and the cyl had 95% leakage. well that makes sences with the 40 PSI cranking compretion.
with it hooked up we lisened to where it was coming from and it was the exhauset. so with this we tore the engine down to look at the valve. and the vlave is perfenctly fine some carbon build up but nothing is worn cracked burned or other wise damaged.
so why did this have no compretion? could it be the carbon wa so built up it could not seal ringht or is there any thing else we can look at?
the car has a dead cylander (#5) we check fuel and spark and it is fine has brand new plugs, wires, coil, and opti (it failed earlier)
we do a compretion test #1 had 182 PSI, #3 had 180 PSI, #5 had 40 PSI at this pont we stoped seeing as we found are problem (we did finish it later and the rest was fine)
we get the leak down tester take the vlave cover off get #5 to TDC by watching the rockers and a scew driver we put in the plug hole. we set the tester up and the cyl had 95% leakage. well that makes sences with the 40 PSI cranking compretion.
with it hooked up we lisened to where it was coming from and it was the exhauset. so with this we tore the engine down to look at the valve. and the vlave is perfenctly fine some carbon build up but nothing is worn cracked burned or other wise damaged.
so why did this have no compretion? could it be the carbon wa so built up it could not seal ringht or is there any thing else we can look at?