Compression test results

[dadsgreentruck]

I did a valve adjustment and a compression test today. I have a strange ticking noise going on that I thought was an exhaust leak, but after changing the manifold gaskets and exhaust donuts it didn't go away so now I'm at a loss as to what it could be. It seems to be coming from the general area of #1 cylinder, but it's hard to localize. I thought it might be a bit of valve clatter but the noise remains after adjusting them. My compression test looks a little odd though, I think...

#1 - 150 first two tests, then I came back to it at the end and it was 130.
#2 - 130
#3 - 130
#4 - 130
#5 - 130
#6 - 130
#7 - 120
#8 - 110

I did each cylinder 2-3 times to make sure I was getting a consistent result (engine warm, by the way).

Spark plugs look pretty much identical; black carbon base with tan insulator and electrode, except for #7 and #8 which are somewhat darker.

Any thoughts on where to go from here?

[bigsnookmaster]

It could be a weak hydraulic lifter.They will usually still run pretty good,but just a little noisy.

[JimKshortstep4x4]

The fuel pump can make a ticking noise so it might be worth checking it.
I use a long screw driver as a "listening stick". with the engine running and the screw driver blade on the fuel pump and the handle held to your ear you can hear if the tick is the same as what you are hearing.

It can also be used to listen to the valve noise through the valve cover to isolate any noise.

Jim

[dadsgreentruck]

So... I took a listen to the fuel pump. If I place the "listening stick" at the top of the pump where it connects to the block I can here it loud and clear.

It's a fairly new (as in low miles) pump. As I recall, its made this noise for a very long time. Are they supposed to be quite? My other truck has an electric, so I have have nothing to compare with.

By the way, how do my compression numbers look?

Tim

[El Jay]

Originally Posted by dadsgreentruck

I did a valve adjustment and a compression test today. I have a strange ticking noise going on that I thought was an exhaust leak, but after changing the manifold gaskets and exhaust donuts it didn't go away so now I'm at a loss as to what it could be. It seems to be coming from the general area of #1 cylinder, but it's hard to localize. I thought it might be a bit of valve clatter but the noise remains after adjusting them. My compression test looks a little odd though, I think...

#1 - 150 first two tests, then I came back to it at the end and it was 130.
#2 - 130
#3 - 130
#4 - 130
#5 - 130
#6 - 130
#7 - 120
#8 - 110

I did each cylinder 2-3 times to make sure I was getting a consistent result (engine warm, by the way).

Spark plugs look pretty much identical; black carbon base with tan insulator and electrode, except for #7 and #8 which are somewhat darker.

Any thoughts on where to go from here?

Were you cranking the engine with all the plugs out son it could "spin" free?
Are those "dry" tests?
Did you also test the compression "wet", i.e., after adding a little oil to teach cylinder.

#8 seems a bit low.
If I recall correctly, the low cylinder should be roughly 80% of the high cylinder.
Depending on the results of a "wet" vs "dry" test, it can help determine things like; bad rings. or piston(s), or bad valves, jumped timing chain, etc.

[JimKshortstep4x4]

Does the click in the pump correspond with the tick that you can hear without the stick?

The compression numbers as you have listed them are on the low side but the engine should run ok.

Jim