Valve train?

[Sgt Gus]

Seems obvious from video but, if I put my stethoscope on valve cover it sounds normal. I've had that scope on everything and can't figure out for sure.
I'm gonna take it to mech shop and leave overnight. Have them give an opinion and go from there.
I don't find any exhaust leaks otherthan a little from the donuts.

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[Sgt Gus]

Took it by the local shop (with appt) just to determine what it might be, and if safe to drive to engine builder. Main mechanic, to young and says he didn't know enough to diagnose or determine anything on a classic. I explained what it was and what I was trying to accomplish. He put his scope on to appease me. Nice enough, but, and I get it, but...okay. Just thought interesting.

 

[TotalyHucked]

If there's no exhaust leaks, I'd probably lean toward a lifter or a loose rocker/bent pushrod/something out of whack in the valve train. I've got a little bit of that on my 5.3 I just rebuilt in my daily, pretty sure I have 1 or 2 lifters that don't quite pump up enough apparently

 

[Sgt Gus]

I sent two videos to builder with noise and one of the break-in videos. They heard noise and thought probably lifter. So, waiting for plan. I imagine I'll need to have it flat bed over there. That will be a bummer. Feeling some denial on my part.

 

[legopnuematic]

Check the flex plate/converter bolts too. Easy enough to verify.

My hearing is kind of crap, but is the sound timed with the crank or is it 1/2 speed of engine rpm (valve train)?

 

[TotalyHucked]

I sent two videos to builder with noise and one of the break-in videos. They heard noise and thought probably lifter. So, waiting for plan. I imagine I'll need to have it flat bed over there. That will be a bummer. Feeling some denial on my part.

Good thing is, it doesn't sound like it's hurting itself

 

[TotalyHucked]

Check the flex plate/converter bolts too. Easy enough to verify.

My hearing is kind of crap, but is the sound timed with the crank or is it 1/2 speed of engine rpm (valve train)?

Sounds camshaft speed to me

 

[Sgt Gus]

Check the flex plate/converter bolts too. Easy enough to verify.

My hearing is kind of crap, but is the sound timed with the crank or is it 1/2 speed of engine rpm (valve train)?

Okay, I will, cover is off anyway.
Sounds more dominant from drivers side.
Sounds like cam shaft rotion, rpm, not half speed. BUT, I am a diy.

 

[Sgt Gus]

FYI, hydraulic roller lifters and roller rockers.
Comp cam, stockish recommended and their recommended parts.
If lifter, hoping just clogged somehow.

 

[Ricko1966]

FYI, hydraulic roller lifters and roller rockers.
Comp cam, stockish recommended and their recommended parts.
If lifter, hoping just clogged somehow.

Did you upgrade the springs and was this an O.E. roller or retro? Rollers need heavier springs.If they don't have enough spring to close the valves with the heavier lifters,they'll tag the pistons and crack the lifter at the roller. Then people blame cheap lifters,nope just the weakest link in the chain.

 

[Sgt Gus]

Did you upgrade the springs and was this an O.E. roller or retro? Rollers need heavier springs.If they don't have enough spring to close the valves with the heavier lifters,they'll tag the pistons and crack the lifter at the roller. Then people blame cheap lifters,nope just the weakest link in the chain.

Reto cam and lifter kit, recommended heavy valve springs, locks, retainers by comp.
I could pull valve cover er if they want me too. Based on what I think I know about preload and tightening, nothing should be loose?

 

[Sgt Gus]

Okay, I will, cover is off anyway.
Sounds more dominant from drivers side.
Sounds like cam shaft rotion, rpm, not half speed. BUT, I am a diy.

I checked bolts on flexplate and converter. I also looked for any bolts from anything near rotating parts

 

[Sgt Gus]

https://www.gmsquarebody.com/attachments/20241019_135938-jpg.368360/

Post 22, 23 Betty Blue build page

 

[Jawzjeep]

This probably isn't the issue but throwing it out there in case. I had a tap in my k5 after an engine swap and I chased it until I started pulling my hair out. It turned out to be the Bendix spring on the starter letting the gear just contact the flywheel.

Hope you find the problem!

 

[xm20k]

Definitely sounds like valvetrain, rocker or lifter.
Mabey missed one when setting lash or maybe ones not pumping up.

'I've seen lifter issues even from top brands, oil holes not drilled, flat tappets with no crown etc.