Excessive piston to bore clearance issue or wrist pin will not show on compression test. you will have to visually inspect piston skirt and measure bore and piston.

 

boooo, that sucks.

 

took off belt. didn't help same noise. when you first start it, its loud then it kinda goes away until you make a load. or if you give it a slight rev, when it revs down you can hear it.

 

What you just described sounds like a piston problem.

 

gggrrrrrrrr that sucks. so do i replace just the one or all of them?

 

If your going to pull the motor and then tear it down I would replace all. Make sure to measure the bore and make sure its not scored or egg shaped. I feel your pain. I bought a Lingenfelter 383 that rattled. I refused to believe it was the new motor. Went through and changed heads and lifters. Finally found out that the motor had excessive piston to wall clearance and scored up the new block. Find a good local machine shop you can trust and set up the piston to wall cearance no more than .002 at the skirt to keep it quiet. Of course I also blew up the motor the good local guy built for me so my head has hit the brick wall a few times too!! LOL

 

so where is a good place to get a loan for eng builds lol.

 

you could get a 5.3 short or longblock dirt cheap

 

I'm not gonna lie... that sounds like a rod knocking just not quite as deep of a 'thud' to it

 

on my honda that had a spun rod bearing i could pull the plug wire to the cyl and the nock would go away. it doesn't go away when i do it on the truck.