was doing a routine oil change when something popped out the drain.... any one seen this before? looks to be some sort of broken tap. the black tube is hollow maybe to allow fluids to pass? it seems to look like a M8 x 1.0 tap but there is no writing on it

 

 

i dont think so. as this is M8 x 1.0 according to my tap set.
i wonder if its been in there since they assembled the engine back in 2003.
not an ordinary off the shelf tap. at least from what i have looked at. the tip is a tap but the shank is a hollow tube.

 

be happy it couldn’t float around and wasn’t lighter and get jammed in the crank/ rods….weird anyway…might have been a thread chaser for the rods, during Assembly…

 

looks like some form of thread cleaning tool

Neal

 

Check thread pitch again>>>>>>>>6.0L (LQ4, LQ9)

 

First photo: definitely a thread chaser. A piece of it, since it would have had a handle attached to the missing part to turn it.
Does it look like a clean break? And it was NOT for the oil drain plug rethreading, since it was small enough to pop out of the oil pan drain plug hole.

But never seen a hollow one. Weaker, so must be designed to cut softer metal like aluminum or plastic?
Is it hollow so that you can attach a suction hose to it to remove the debris from the cutting? Would be useful for a blind hole. Only guessing.

Did someone rebuilt the engine at some point? If so, did they forget this inside the engine?
Perhaps, guessing now, it broke and that end was left inside the partially rethreaded hole (which means a bolt that should go there was never put back)
Maybe part of a HeliCoil tap of some brand? Or a clean break on the tap tube? Does it look like it was sheared off? Does not look that way from the photo.

Second photo: blurry mess, what are you trying to show?

Either way, No Bueno. That is nasty sh*t, whatever the reason is.

Now consider this: For this to perfectly line up and pop out of the drain hole is some sort of miracle. Your Hummer is telling you something.

Now you know what that rolling banging metal sound was that was coming from the bottom of your engine on ever corner of the road, LOL!

The bigger question is, is the other half still stuck inside your engine?

 

the second picture was of the tip that is a tap but the camera would not focus on it no matter what i did.
yes it does look like the tip has been snapped pretty cleanly off.
i never have heard banging coming from the engine thank g_d.
i do not know if there was ever any engine work prior to my ownership but i do not believe there was since i have basically had to do many services that would have been done during any repairs like replacing the original iridium spark plugs that where pretty worn out, valve cover gaskets, motor mounts, exhaust manifolds and bolts,

 

I never found anything in any of the oil pans I have drained.

That is crazy.

 

I could be off base with this, as it's hard to tell the size from the photos. I had a situation where I had to remove my dipstick tube. But it broke off flush at the block. I was able to extract the very top portion that goes through the block, but the rest of it broke and fell down into the pan. I was freaking out and wasn't able to magnet it out from up top. But I was able to use a magnet to fish it out of the oil drain hole. It was very similar to your photos (minus the thread chaser, but they could of been using the thread chaser to try to get it pulled out of the block...a little rust and corrosion...mine was stupid how seized it was...but I did use a thread chaser at one point to try to get a bolt in the piece to yank it out from up top).

Just an idea.