Gun Jam

my money is on collapsed lifter.

Remove the valve cover and roll the engine over by hand until the rocker arm on the suspect valve is all the way and unloaded (the lifter will be sitting on the cam's base circle) you should be able to wiggle the rocker arm side to side as there will be very little pressure on it.

Now push down on the back of the rocker arm directly above the pushrod and see if you can force the pushrod down. The pushrod should feel rock solid.

If you push down on the rocker arm above the pushrod and it goes squish squish and the pushrod moves down about 1/8" then there is as very very good chance that lifter is collapsed.

-Gun

Harwich

P Zero - I am running rotella 15W-40. I have had the intake and heads off and the engine looks very clean. I have never had the oil pan off to see the bottom end. According to previous owner it only has about 5k since rebuilt but I can't prove that.

Gun Jam - I actually just ordered a new lifter today. They are cheap and it doesn't take that long to pull the intake and swap it out. So even though the lifters are new I am going to try replacing it. Maybe I got a bad one.


Thanks

Gun Jam

cheep and easy until you go to pull it out and it runs into the head.....if you are running a roller cam with link bar roller lifters you may have this issue if not probably no biggie then.

Either way its a lot quicker to check by using the above described method. If its rock solid when you push on it doing anything with it is a total waste of time and money as well as unnecessary wear on the cam lobe due to a new lifter needing to seat.

-Gun

Harwich

Gun Jam - "cheep and easy until you go to pull it out and it runs into the head...."

I am sorry but I have no idea what that means. Maybe it's because I have never worked on anything with a roller cam. Maybe if I had I would understand what that means. This is just hydraulic flat tappet cam. I am going to check it the way you suggested when I get home tonight and go from there. I went a head and ordered a lifter because they are cheap and I will probably try replacing the lifter before I pull the head.

Thanks for your advice.

Harwich

Gun Jam - OK, I tried your suggestion. I used the heel of my hand and pushed HARD and could not get the rocker arm to move.

Mark - I listened to the fuel pump and I can definitely hear a tapping as it runs. I can't tell if it is the same sound I am hearing or not. I have never put a stethoscope on a fuel pump before so I don't know if the sound I am hearing is normal or not.

Gun Jam

can you post a quality video of the sound filmed from multiple locations?

Tracking down these sources of noise can indeed be tricky

Film it with change in engine rpm as well (wing the throttle level and advance in nice and smooth to about 2,000 rpm)

If you are indeed running a flat tappet lifter then you should be able to remove it simply by pulling the intake it will not hit the head when you slide it out. Link bar roller lifter sit up a bit higher and in most cases can not be removed with the head on.

If the pushrod felt solid with no pressure on the rocker arm (one would be able to roll the pushrod with thumb and index finger) there is a very good chance its not a lifter issue.

-Gun

Harwich

Sorry for the long delay but I just recently got this resolved.

VERY long story short. It was the camshaft, apparently it was a little bent.
I built a new engine and the sound followed. The camshaft was one of the very few things that came from the old engine. I changed it and the sound was gone. Unfortunately there is another issue with the new engine but I will start a new thread for that. Thanks to everyone who posted on this thread.