# 8 cyl zero compression

[A97obs]

Yes leak down test time

It’s fixed the valves were open causing zero compression. I had over tightened the pre load on cyl 8

 

[A97obs]

Loosen the rocker arms also before you do this. Great advise

That was the fix

 

[A97obs]

Put compressed air to the suspect cylinder. If you hear air coming out of the tail pipe you have a exhaust valve problem, if you hear air coming out of the Throttle body you have an intake valve problem, if you hear air coming out of the dipstick tube, oil fill cap or PCV grommet you have a piston ring problem

Rocker preload was to tight , it’s fixed 150 psi cyl 8

 

[A97obs]

You've done a total or dynamic compression test. Step two is to a compression Leakdown check / test. Are familiar with that type? Where you input a regulated pressure and read how effective the compression is, and or identify where what the broken or worn parts are. By identifying where the input pressure is escaping from. Crankcase worn rings, exhaust - exhaust valve, throttle body- intake valve.
There's probably tons of you tube vids. Do you have a cheap borescope, stick in spark plug hole?

It’s fixed it was 100% the rocker preload a little to much back to 150 psi on cyl 8

 

[GoToGuy]

Usually the first response is " what did you touch, recheck your work " . As some are " self induced problem ".