1) Get an accurate oil gauge on the engine, and see how the pressure compares to what is spec'd.
2) Change the oil again in 500 miles and see what you find in it.
3) Pull the pan and do a visual inspection of at least some of the bearings, if not too labor intensive.
It seems possible that some copper manufacturing debris could have been in the replaced cooler lines, but that seems a bit excessive. I would do at least a few frequent oil changes to flush the system, and then make UOA's a habit to monitor what is going on.
My first mistake: didn't get 1 done
Plus, not sure if a simple PPI would have discovered the shavings/flakes or whatever it is
I assume they check the dipstick and the copper should show pretty clearly. And if the engine takes a dump in the first month or two, you have someone to blame or at least make repairs at a steep discount.
If the material is from the inserts there should be lead babbit and copper, from the pics it looks like the copper is from some other source. With all the disparate clues the rods should be checked then go from there.
Bunch of stabbing guesses here. If me, I would start submitting an oil sample and then run it for a OCI and resubmit for another oil sample and see what trends up or down. I would do this for at least 2-3 OCI's. If copper trends down, then more than likely the oil cooler replacement.
Maybe some kind of oil additive? There are additives that have soft metals in them, like engine restore. Engine restore uses a "CSL" formula which to my knowledge is copper, silver and lead. The formulation is supposed to be small enough in microns that they shouldn't be visible.
The bottle does state to shake well as the first instruction step. I suspect if it does precipitate out over time it could build up and be visible? I have no idea how it would react in an oil pan over time.
Hypothetically even if engine restore caused it, why did the owner use engine restore? That in and of itself may be indicative of a problem.
Exactly what I was thinking. I would do a compression and leak down test, and at least get an idea of how things are looking based on those tests. Then a couple of short OCI's and hope for the best. A UOA now and after the short OCIs might be of some benefit. As mentioned it could also be copper from part replacements.
You never really know what viscosity was in the engine when you got it, could it be a higher viscosity masking a problem? possibly, you never know. If it were me, I would change the oil and filter, maybe a good 5w40 - 10w40, give it a run of about 2k and then change it again. If it were flakes from work done then you will not see nearly as much this time. The change you do would be the sample to send in because you know what you poured in and the true run time on the oil. After this you can begin diagnosing.
That much has to have a serious source. Could deft be thrust bearing. I've seen a lot that appear to be exposed copper straight out of the box.
Crank walking takes quite a bit to start making noise. I'd check the crank play for sure. May be tough to pull off since that engine is smashed in there and then has shims inserted (other parts) to make it extra tight.