piston or valve?

[qikr33]

hi all i have just done a compression test and the results were as follows

1)145 psi

2)150 psi

3)145 psi

4)146 psi

5)0 no needle movement what so ever

6)150 psi

What do you guys think has happened.

I am thinking a valve is open in cylinder 5.When the engine cranks over you can hear a consistent noise out the exhaust like a open valve noise.But could there be a piston problem.

Does anyone estimate the price of this job or has anyone had this kind of work done and what is the worst case senario

[Aurora]

Does it sound kind of a like a backfiring in the intake?

[Sydneykid]

Hi qikr33, check the valve clearances that will tell you if it's a valve. What you have done is called a "dry" compression test. What you can also do is a "wet" compression test. Squirt a fair bit of oil into the cylinder and check the compression again. If there is compression then it's pistons and rings, if there is still no compression then it's valves.

Hope that helps

[qikr33]

ok guess what guys i though i would check the valves out so i took off the rocker cover for the exhaust cam and.....it is snapped in two places just after the first cam lobe.so the whole head is coming off not good and not happy.

[RS500]

the head would've had to come off anyway as to have found whether it was a valve or piston problem, but it looks like you've found your problem so i'll just shut up then ;-)