Piston skirt slap when cold....I think..

[NSFW]

Ever since I got it, On the cool mornings on start, (5.3L LM7 2k Silverado) I can hear/feel a tapping from down low on the block when running, seems to dissipate as the engine warms up but never really goes away. Intensifies a bunch with applied throttle when cold. Oil pressure doesn't seem to effect its presence. Engine has 400+ thousand on it. Well taken care of etc, never harmed it one time while I have had it, not chipped previously.

Pretty sure I got a piston skirt slapping the block, #2 or #4 cyl. Can feel it with the defenders on, my fingers against the block in that area and my other hand cracking the throttle body. Feels similar to the light tapping of a coffee cup on its edge against the counter top...you know?

I'd like a 2nd opinion if thats cool. It does it now and then after a highway run also. And I will note its starting to sound like a d-max under WOT, or its resembling
that sound but been thinking about a diesel.. that might just be on the brain.

Can I do anything short of a overhaul about this. Am I in more trouble then I am aware of here? Does it even need it? Should I be worried even? Or should I be on the phone getting a crate motor on the truck.

Thx in advance.

[muddkatt]

Piston slap only occurs when the engine is cold and is started. Usually last a couple of minutes. I have never heard piston slap on a 5.3 once the engine is warm, so the d-max/highway part you are describing doesn't appear to be piston slap to me.

 

My 01 has had the piston slap since it was new, now has about 311K miles and should last another 300K as long as something abnormal doesn't happen.

[efritz]

the early 6.0s are very noisy, they just are.. Mine is loud, they all get piston skirt wear and gets louder as the miles rack up. Just run the truck, enjoy it turn up the radio... Autograph style

[Spurshot]

I would suspect lifter noise in these engines before piston skirt slap. But at 400k, anything is possible.

 

Not good odds that it can be diagnosed on the internet. Need a good mechanic that can I.D. the difference between a piston slap @ 1 to 1 noise per revolution verses a lifter @ 1 noise to 2 revolutions. If its 1 to 1 it still could be something else, like a rod bearing knock. Especially, since we are dealing with a 400k engine and you said it sounds like a diesel hammering away.

[SpartanAutoworx]

Sounds like a dirty lifter on the drivers side to me. You can attempt to clean them if you removed the valve cover and spray carb cleaner down the push rod hole.

 

I have an engine that has 209 on it with lifter tick. Im going to attempt to clean it next oil change.

[Ghostrider66620]

its a worn oil pick up oring. this causes a low pressure issue that doesn't look like an issue on your gauge. it acts like piston slap or lifter tick. try a bottle of Lucas oil additive. if this lessens the noise or it goes away..the thicker/stickier fluid is sealing the oring and stabilizing the pressure.

[NSFW]

Allright.. I will look into all of your suggestions and report back. Thanks for the input guys.