Say hello to my new friend! His name is rod knock.

In reply to rslifkin :

If timing chain guide pieces are getting into your oil, rod has already exited the building and you've got much bigger issues. 

captdownshift (Forum Supporter) said:

In reply to rslifkin :

If timing chain guide pieces are getting into your oil, rod has already exited the building and you've got much bigger issues. 

Maybe, maybe not.  Stuff from the timing chain guides would go right to the pan in most engines.  From there, it gets sucked up, abuses the oil pump a bit (for anything small enough to get through the pickup screen) and goes right into the filter.  It's one of the few sources of metal that often doesn't scatter metal bits into bearings, etc. 

So is there any way to test/check my timing chain tensioner/guides, or is the only solution for that to pull the front of the motor off and get in there?  The timing chain guides and tensioners were problematic on the early iterations of this motor, from what I've been reading.

I saw this, I suck with tech so just screen shot'd it 

I am loathe to offer advice these days, but you're no further ahead now than you were a month ago.

Cutting open a filter in this situation serves no practical purpose. Great, now you know you have E36 M3 in your oil. How has that helped you to determine what the problem is? It hasn't.

You need to determine, through troubleshooting, where the noise is coming from and what it is.

I haven't really been following this but I don't recall seeing anything about oil pressure. Is the light on? Is it OK? Have you checked it? Have you pulled the plugs yet? They often tell a story. A compression check would probably be next. Once the plugs are out you can do an easy test to determine if a rod bearing is actually the problem.

You need to get back to basics and do some troubleshooting to find out what you really have going on there.

Thanks Peabody.  What is the easy test for the rod bearing you mention?  Things like that should be my next step.  I'm looking at 5-6 grand to replace the engine right now, so if there's even a small chance it's something other than a major bearing, I'll take it.

In reply to infinitenexus :

It really doesn't matter where the metal is coming from.  If the oil filter is full of metal shrapnel, then that stuff is circulating everywhere and the engine has to come out.  The pistons probably have metal embedded in their skirts.  The cam bearings may be scored.  Etc.

It's normal to see a little metallic sheen but if you see chunks, or the oil in the filter looks like silver nail polish, well...

Maybe. Maybe not.

It is in the filter, and that's what it's there for.  It's certainly not ideal, but I've fixed motors with problems like that, that have lasted a long time.

Or at least long enough

In reply to infinitenexus :

Get your hands on an automotive syringe, the kind you would use to change the fluid in the diff. When the plugs are out either buy or make an adapter that goes from the plug thread to a hose. Thread it in the cylinder and with both valves closed, attach the hose to the syringe and move the handle up and down. If you have an errant rod bearing you'll hear the rod clunk against the crank or piston hit the head. You may, after pulling the plugs, know exactly what cylinder to start with.

In reply to Peabody :

I've done repairs like that too, and hile half the time it worked, half the time it came back to bite me in the ass.  Usually on DOHC engines with variable valve timing, the crud circulated long enough that the cam journals scored, and low oil pressure was causing cam timing control issues.  "If you can't afford to do it right, you can't afford to do it twice"

I'm working off of the assumption that significant metal in the filter means that the bypass was opening, allowing the junk to flow through the system.

You have spun a rod.  The sound you hear from the top of the engine is the piston hitting the cylinder head.

Assuming any less will cost you a bunch of pain. If it turns out to be less, you win.

The engine is coming out, and coming apart.  There is no other reasonable route to take from here.

Edit: Lots of gt 5.0 engines on car-part.com in Florida and area for about $3k.