Piston movement

[K-rover]

I'm tearing into my 4.0 after getting a pretty bad tick.
Quick back story. This is the second engine in this truck. Its been solid for the last 15yrs, although it's had a bottom end knock for sam amount of time. No driveability issues, no over heating, just a faint knock at idle. The new tick started shortly after I replaced the valley pan gasket.
I'm fairly certain the tick was from the two collapsed lifters i found. Now Im trying to find the original knock. I have the heads off and plan on pulling the engine on Monday, but I was noticing that i have lateral movement on all 8 pistons. Its not a lot, but how much is acceptable? Could that be my knock?
I plan on pulling the caps and checking the bearings as well.

 

[Grum.man]

I'm tearing into my 4.0 after getting a pretty bad tick.
Quick back story. This is the second engine in this truck. Its been solid for the last 15yrs, although it's had a bottom end knock for sam amount of time. No driveability issues, no over heating, just a faint knock at idle. The new tick started shortly after I replaced the valley pan gasket.
I'm fairly certain the tick was from the two collapsed lifters i found. Now Im trying to find the original knock. I have the heads off and plan on pulling the engine on Monday, but I was noticing that i have lateral movement on all 8 pistons. Its not a lot, but how much is acceptable? Could that be my knock?
I plan on pulling the caps and checking the bearings as well.

.001-.002 according to RAVE

 

[Dogbreath077]

Since you're tearing it down, here's one of a few videos you may find useful. Check them out, as these are real videos, by an L1 Master Tech, Engine machinist (me). I made the channel to help out the DIY and it not a monetized channel and i have no advertisements.

 

[Knightspirit]

Since you're tearing it down, here's one of a few videos you may find useful. Check them out, as these are real videos, by an L1 Master Tech, Engine machinist (me). I made the channel to help out the DIY and it not a monetized channel and i have no advertisements.

Thanks so much for creating so many videos on your channel! I am working on putting together a new rebuilt 4.0 for my Disco this year (I've been sitting on it for well over a year now - current motor is running great - but has the same tick as K-rover describes). I am looking forward to reviewing all of your content!

 

[kris812]

I don't think those pistons should be moveable.. Sounds like piston slap if they wobble around.. Guessing it was honed out and pistons never changed..