Leak Down Test Results

[jhenegh]

Chasing down a weird sound in my truck. Posted a few threads about it with little response. Mel suggested maybe an intake valve issue so I decided to do a leakdown test. Regulated air at 100psi going in. Here is what we have:

1: 80 psi
3: 78 psi
5: 87 psi
7: 87 psi

2: 62 psi
4: 88 psi
6: 75 psi
8: 90 psi

I think I have an issue in my heads

 

[IDIoit]

if you have done a leak down test,
where was the air escaping?
yes you have a percentage of leak down going on, especially #2

but with the valves closed, there are only 4 places for the air to escape.
crank case
coolant system
intake
exhaust

which one was letting the air escape?

 

[jhenegh]

if you have done a leak down test,
where was the air escaping?
yes you have a percentage of leak down going on, especially #2

but with the valves closed, there are only 4 places for the air to escape.
crank case
coolant system
intake
exhaust

which one was letting the air escape?

Forgot to say, had the exhaust open at the manifolds, valve covers off, intake snail off and radiator cap off. The air could be heard escaping plain as day from the intake

 

[IDIoit]

did you go through the injector or glow plug hole?
you made sure the valves were off the cam lobes, right?

if so, sounds like the heads need to be done.

sounds like a perfect excuse for studs and Russ's cam!

 

[jhenegh]

I went through the glow plug hole

I loosened all the rockers to ensure all the valves were closed. Did each cylinder this way because I couldn't get the engine at perfect TDC in the 4 separate positions without the air pressure pushing the piston back down and opening valves. I admittedly did the leakdown with the pistons at the bottom of the bore but I was more concerned about checking the valves/heads with this test rather than the rings

 

[IDIoit]

Long as the valves were closed, you get a correct reading.