This is just a wild butt guess, but with a knock and copper my guess would be be a bad con-rod bearing. The only copper in the engines is in the bearings, right? Also, the knock of con-rod bearing knock could be mistaken for a bad wrist pin, either way something has happened it seems.

Do an oil analysis search in the tech section, there are some guys that do it.


[Modified by CPT Z06, 10:18 AM 6/28/2003]

Aluminum 5
Chromium 1
Iron 23
Copper 3
Lead 7
Tin 1
Molebdenum 71
nickel 1
Manganese 1
silicon 8
sodium 10

sus viscosity 63.1
flashpoint 395

23ppm of iron in 6000 miles is about twice as high as it should be, although if you drove in any extremely cold weather during this interval, don't worry about that number, as it'll be lower in the summer. Iron numbers tend to be high during the wintertime. The lead wear of only 7ppm in 6k is very good for a hard driven car, this shows the bearings are getting good protection. Copper of only 3ppm is excellent for an LS1, but proves that once these engines are fully broken in, the copper is low. When new you'll often see as much as 200ppm in a 3000 mile interval! It usually doesn't come down to a low level until after 40 or 50k.
You should try an interval with the K&N oil filter to see if your numbers come down. I'd be a bit worried about those iron numbers if you didn't see cold weather.

Here is a link to my first analysis using a Mobil-1 filter and Amsoil 5W-30. About the same mileage as you. My car didn't see cold weather, and my iron is about half of yours. However, note my copper This is typical of the LS-1 and the theory I have seen is it is the center cam bearing wearing in. The copper typically drops by around 20K miles.

So the high cooper is normal, but what about the knock?