Rapid Unscheduled Disassembly inside Valve Cover

[baon3h]

I adjusted the valves on my '68 280SL for the first time. Everything went well until I tried to put the valve cover back on. I noticed a rattling sound coming from the valve cover as I tried to position it. After further inspection I noticed a hole in the sheet metal that is riveted onto the cover on the inside (see pictures).

Something must have hit the sheet metal with quite some force and ripped out a good chunk of metal (last picture). I found it lodged in the gap behind the hole. I have no clue how and when this happened, I've owned this car for only 6 months. The engine runs fine, has good compression, rockers and springs are all attached and in good condition and it  doesn't burn oil.

My question is, do I need to address this or can I keep running the engine with this hole in the sheet metal?

What the purpose of this sheet metal? Does it help with oil circulation? What could have caused this?

[Pawel66]

This channel plays a role in engine venting, this is what it is for.

The trouble is that it becomes very clogged with oil residuals. When you restore a car there is no other way to clean then to drill out the rivets and rivet i ton back again, which is not simple. I think, as it is clean inside and rivets do not seem original, that that was the procedure performed here.

I would check if it is not lose. If it is, it has to be removed.

Personally I would not leave it like that, but I am not qualified to say if you can drive without it. I would definitely replace it or replace the valve cover.

Another question is what smashed it. Was it just because it was lose, it went down a bit and got hit by cam or valve lever? Or something else happened there?

Someone may chime in with advise if engine oil passages need to be flushed to get rid of any potential small metal debris.

[baon3h]

Thanks, Pawel! It's not loose. I did some more digging and it looks like one of the head bolts went airborne. In the attached photo you can clearly see the path of destruction. The hole in the baffle is about the same diameter as the bolt.

This must have happened a while ago. The oil and filter from the last oil change were clean and didn't contain any large metal fragments.