Dirty Howie

Do any of you guys know what this is? Was stuck to the main magnetic drain plug, not the one on the external tank.

Poor quality cell phone picture. Looks like piston ring to me (but I'm no expert). Very flat about 1mm thick, about 4 mm wide, and the longer piece almost 1/2 inch.

Car runs good !!!


DH

sperkins

Looks like it to me with the quality of pics posted. If it is a ring, it would almost have to be a compression ring since the oil rings are above it.
May be time for a leakdown or compression test at minimum.

fatbillybob

Dh,

How about a piece of bearing cage? I would search an ls7 exploded diagram for possible candidates. Maybe in the timing gear area? I do not see how piston ring can end up in oil unless engine go bang since ring is contained in the ring land. Get a better picture. Is the metal all chewed up or clean break with sharp edge details? I assume from engine oil plug?

Dirty Howie

Carl

It is only on the engine oil plug. And yes seemed like clean break with sharp edges.

I really don't know what else it could be besides piston ring. But I also don't know what the inside of an engine and all the valve train parts look like. But I'm hoping one of you guys could at least list the possibilities.


DH

mgarfias

Looks like a sealing ring to me. How it got past the oil ring is beyond me. Last time I had an issue with one of those, it went out the exhaust valve. If it was a gen1.5 motor I'd suggest maybe a cam retaining ring, but I'm not sure what the gen3/4 motors look like with regard to that.

I'd be taking the motor out and tearing it down.

Dirty Howie

Sorry for my ignorance but what is a sealing ring and where in the engine would it be from?


DH

RAFTRACER

Looks more like a piece of valve spring to me.......I have found valve springs doing this on LS7's before.......Hope that it is......a whole lot easier....I'd pull the valve covers tomorrow.

Are those pieces flat on both sides ?? Or is one side rounded ?? If it has a rounded side start looking at the base of the valve springs...

Charley Hoyt

Sorry to hear about this Howie. Hopfully it is an easy repair.

The top ring (or rings) is (/are) called sealing ring. the bottom ring is of a different construction and is use to control the oil on the cylinder walls. I don't know how one of the top rings could be in the oil pan without extensive damage to one of the pistons or the block. Seems unlikely that it could be a ring. Unfortunately I don't know what it is.

Best of luck,
Charley

mgarfias

Huh, that had occurred to me, but figured they'd be wound with round (or oval) wire. Like I said though, I've not torn down a gen3/4 motor yet.

Dirty Howie

Thanks for the specific inquiry. It appeared flat on both sides which is how a piston ring would look, I think. Isn't 1mm thick, too thin to be any part of the spring??


DH

fatbillybob

We need more clues like better pics with context like a ruler. Take the valve covers off to start and inspect. I would be thinking piece of broken lifter like retaining ring or maybe a valve retainer edge breaking off or a piece of valve spring toward the flat end as opposed to the middle of a coil. I would stop driving the car. You could have an item on it's last legs and complete failure of the item would be like #18 loose on a 4 unit bridge fracturing #21 to the gum line....get it? And with 77k miles if you don't find the problem refreshing the motor is not a bad idea on a track car. There have been instances of junk left by the factory in gearboxes and crankcases.

Dirty Howie

Thanks for the insight Charley. So couldn't it be the lowest ring failing with out damaging the block or piston?

And others have said they don't know how a ring could get to the pan and oil plug. I don't understand that ..... where else would it go??


DH

Charley Hoyt

Not likely....I have never taken an Ls-7 apart...but I have overhauled many aircraft engines (which are admittedly different)....But the cylinder to piston clearance is too small for a piece of a piston to pass by without severely scoring the cylinder wall and/or piston. Hopefully this is part of the valve train or some sort of shim.

Charley

Dirty Howie

Carl

Sounds like implant time.

The pieces were found saturday at the dealer where I get my oil changed. I put the magnetic plugs in when I first go the car in hopes of catching a problem before it was too late. I wouldn't even let them start it after adding the oil. Its sitting there waiting for the main tech to look at the parts tuesday morning.

I wish I had a better camera at the time but I did not. If the dealer takes pics to send to GM I will get a copy. Otherwise I will be going there wednesday morning and take some good shots.

Car has 77K, do you really think mechanics junk is just finding its way to the oil pan?

Again uniform thickness about 1mm, flat both sides, uniform 4-5mm wide, longer piece almost 1/2 inch with curvature. Diameter of curvature seemed less than that of a large piston ring but not sure.

Thanks for your help


DH

Dirty Howie

Valve train shim would be preferable


DH

MarkBychowski

Looks like a valve spring to me also. If the large piece is .5 inches long, the radius is too small to be a piston ring. The ends of the valve springs are flat on both sides. If it just broke the end off of one of them the car would still run fine.

Should be relatively easy to confirm; just pull off the valve covers and closely inspect all the springs looking for one with a missing end

Charley Hoyt

Howie, I believe the cylinder bore for the LS-7 is 4.125"....Does the larger part that you found look like it would be about that diameter? Hopefully not. Smaller would be better....

Charley

Dirty Howie

Are the ends of the spring 1mm thick??


DH

Dirty Howie

The two guys that looked at it didn't think the curvature was correct for a 4 inch piston ring. I want to believe that but I am not sure.

Probably someone with some good software could resize the camera image down to .5 inch and determine the arc of the piece and extrapolate the circumference.


DH

Dirty Howie

Okay, I just got a CD which is 4.5 inch diameter and measured .5 inches at the circumference. From my memory I think the diameter of the piece would be smaller. But I definitely am not sure.


DH