Solve this puzzle. What Broke?

I am doing forensic on a 996 3.4L 5-chain engine that suffered a low oil pressure event. It looks like a new Short Block is in order. The first picture shows "black non-metal stuff" blocking the oil pick up tube. The second picture shows bits and pieces of metallic ferrous thin pieces of stuff that is sitting at the bottom of the oil pan. What's the black stuff (I have my guess)? What's the metallic stuff that broke?

The black stuff looks like ground up chain guide material. I've seen lots of that on VR6's. No idea what the metal is.

Here are some clues. The black non-mettalic stuff is soft, like rubber, or silicone compound. It's not chain guide.

If it was a low pressure event, the metal is most likely layers of the bearing(s). They are a bit crumpled, but do you see any edges that might have been quite straight?

Thery are not bearing material (although there is a lot of fine bearing dust in the oil). The big metal pieces are magnetic.

The piston coatings are ferrous, but I don�t see why those would come off during the event. Maybe they�ve been there for some time. Which also means you likely have bore scoring�

No bore scoring. The heads are off and I can see the bores.

I�m out. I�m guessing based on bits and pieces I�ve picked up over time. Someone else needs to pick up the game�

Well, if nobody knows, I might just disassemble the short block ...

My guess ims chain guide and crank shell or rod bearing material.

My guess is someone used RTV sealant, which flaked off and blocked the oil pickup, which in turn overheated and spun a bearing or two

Quotes source post: 20048605

i agree if its soft. It hard bits its chain guide. Waiting on op to elaborate.

The black stuff is soft and rubbery. The metal pieces stick to a magnet.

Maybe the black stuff was an oil seal and metal piece were a bearing cage from the IMS bearing?

RTV and timing chain.

This is the size of the bigger pieces, and they are very thin. I frankly do not know what's inside the motor made of this material.

The only place I know that has this ferrous material is piston coatings. Maybe the low pressure event overheated the pistons and the coatings came off during the event. Therefore, no scoring. Maybe a little more info on the low pressure event. What was the described failure? Street, track? Pressure warnings, temperature warnings? No start? As for RTV, where did that come from? When was the last service that used RTV? It�s a lot to block the pickup. Maybe the engine has been pressure starved for sometime and it finally overheated enough. Disassemble!

To me, without having pieces in my hand, going only by your pics.... sure looks like bearings pieces. Probably from a spun rod bearing. Although the bearings top coatings are copper & tin alloy, the shell backing plate is steel (magnetic). My guess, oil pressure instability m96 issues, caused rod bearing to get lose then with excessive clearance bearing finally spun. Engine was continued to be run till bearing totally came apart and it was steel on steel,,, crank journal on rod big end with bearing completely gone into sump in pieces.... Bearing failure could have been helped along if the imsb was also going & shedding steel debris, or bore scoring added aluminum shavings helping bearings destruction. Have seen a few m96 run for quite a while with a spun/worn out rod bearing, with minor/moderate sounding rod knock, before the whole shell disintegrates to pieces in the sump like in above scenario... Its a testament to how good some of the m96 design is that it can go for so long with spun bearings without throwing a rod immediately like many engines do... Thats my take with the info I've got....

Ooh, too big for timing chain. I'm in the bearing camp.

thrust washers of some sort?

Quotes source post: 20050558

Why can�t this be bearings? Don�t bearings have some magnetic components, especially if the different metals have melted together?

...Spun bearings.

That is definitely spun bearings ...note the black discoloring is due to thermal runaway... The bearings have a thin metal steel shell that is lined with a Copper layer ,then a layer of soft "Babbitt" material (Babbitt is lead + tin soft white metal and non-magnetic ) The black rubbery stuff that was blocking the oil pick-up tube is gobs of Silicone that has broken off and gotten chewed by the timing chains.. Root cause/chain reaction = " incompetent grease monkey" using globs of Silicone that became dislodged and circulated through the timing chains and ended up blocking the oil pick-up tube which caused a low flow of oil which caused a thermal runaway of the bearings resulting in blacked spun bearings .....

Sounds completely plausible Porschetech3, that's pretty amazing that its spat the shells out! I've managed to save an engine once that literally started knocking as i pulled into my driveway (not a P-Car but a 20v Toyota powered Lotus 7) bearings were just wearing through to copper and didn't even damage the crank. But i had no idea it could spit them out

@yelcab did you get this engine apart? Take a picture of the "blue/black" Rods to show Rennlisters what Thermal Runaway from lack of lubrication looks like !!