Yeah, that seems common with these motors. My engine had an LS6 intake manifold installed about 6,000 miles prior to this photo. You can bet it was a clean install.

 

I see Paul.............and here after my son had pulled some of the crap out, this is what left. Pine Needles and Grass.

How in the heck does it get there? Does this happen to many motors?

I'll post pictures of the damaged piston later. Not good. =(

 

The junk gets down in the three casting notches for the head bolts between the ports.

As I'm pulling my motor soon (yeah, right!) I'm gonna investigate how to avoid this.

UH-OH! Do tell!

 

Wow what a thread. I am on the fence weather to do this mod. My intake bolts were tightened when I had my cam sensor changed & a mouse ate a few of the wires in my harness behind the intake (nightmare). The only water my car sees is when I wash it & it is garaged.

 

My LS mechanic has stated that he's seen a lot of junk and water under the intake manifolds also and he would have to change out the knock sensors since the water would screw them up.

 

Yup, rtv the the knock sensors incase of water puddles