Im rebuilding my z6 right now and i have the engine on a stand. and i pulled off the girdle and then removed piston 1 (closest to oil pump side). when piston 1 came out i found a little dowel loose (loose as in free as a bird) in the space underneath the piston head. im not sure where it dropped down there from or when. I have looked at expanded pictures of the engine and i still am not sure.

the car was running fine (burning oil like crazy hence rebuild) no knocks or anything and i drove itabout 500 miles before i started rebuilding it. i have had the engine flipped upside down and right side up and it never fell out till i took off the girdle and stuff today. and i never dissambled the head past the head bolts and removing it from the block.

EDIT: this little thing had to come from the lower end somewher ebecause the engine was upside down when i found it. and its a solid piece

*******SOLVED********: it is indeed a pin from the rocker assembly. it fell ut because i was missing a lost motion assembly and somehow made its way dow to my oil pan


here it is.



this is what my engine was like when and where i found it. i ws pushing the piston out from this exact cylinder and lo and behold a little pin dowell thingy chillen in the bottom of the piston

 

Not sure if that is the same size but the first thing that comes to mind is the vtec rocker arm pins.

Looking for: D16Z6 Rocker arm assembly diagram - D-series.org

Last pic on 2nd post.

 

My dowel is solid and the part on mine had to come from the lower end because the engine was upside down when i found it. thank you for your response!

 

that is, as tomcat said. a rocker pin.

not a dowell.

 

i dont see how a rocker pic could hve gotten underneath the pistons unless it has been there since before i removed it. my head has not been taken apart at all. the engine was upside down with the head removed and 5 ft away when i found it.

 

Honda Automotive Parts

i think number 6. if you take apart your rocker assembly look for one missing....ignore the words, picture stolen from google.

they go in there

 

maybe its a magnet off of a magnetic drain plug? will it stick to your fridge?

 

this is something i am definitely going to look into because its actually a possibility i know for a fac this thing is not from a head. thanks man. i updated my original post to add a pic of what step of the breakdown i was at when i found it.

 

i dont think it would be impossible for that to go from the head to the block through an oil return passage.
it would be impossible for it to come out of a rocker and down there without disassembly.

i would have to assume this thing was disassembled before, unless you know it was not.

 

the car was running fine (burning oil like crazy hence rebuild) no knocks or anything and i drove itabout 500 miles before i started rebuilding it. i gues it could have came through like that but i have had the engine flipped upside down and right side up and it never fell out till i took off the girdle and stuff today. and i never dissambled the head past the head bolts and removing it from the block.

thanks for all your help man im just gonna do a super inspection tom and put this thing in every hole to see if it belongs / fits.

 

does it have a dimple in it? such as the ones in these rockers? if so thats definitely it if not i think there are solid ones in the smaller parts that go in the middle

 

no dimples or holes just solid

 

then look inside the vtec rockers, which is the middle one on the intake side when inspecting. you can actually move them and inspect without disassembling the rocker, just pull the assembly off and flip em down

 

It looks like it might be a bit bigger than your vtec pins but maybe not.

The way it would get down under the piston is falls through one of the main oil return passages down to the sump and gets splashed up by the crank up under the piston.

How or if it was lodged is curious.

I'd seriously be inspecting the cylinder walls for nicks and or abrasions just in case it would periodically go flying up cylinders as it bounced around in the sump pan. I'd also check the innards of the pistons and the rods themselves for nicks and abrasions.

It may have been lost by another owner and replaced if all of your pins are currently in place. I would check the rocker arms just to be sure all are in place and go from there.

 

my cylinders are flawless and my rods are good too not to mention the pin has literally no marks on it. it must have gotten there from this dis-assembly process. im going to take a solid look at everyhting tom and i will update this post. thank you for all the help

 

Okay then it sounds like it's been sitting in the bottom of the pan for god knows how long and when you flipped the motor to take the pan, girdle etc off it fell into the cup of the piston.

Might not even be from your car.

I am with you on going over the whole motor with a fine tooth comb none the less. Peace of mind of knowing without a doubt it's not from your car is well worth the extra time and effort.

Cheers.