metal paste on magnetic oil drain plug?

[LeedBoost]

So I just put about 3500miles on the new bottom end and I went to change the oil and there's some buildup of this dark grey metallic paste that gets stuck to the magnet. The breakin process went perfect there was no buildup of this stuff after 1500 miles when I did a final oil change to synthetic oil.now I start seeing this. Does anyone know what this actually is? Is this common? Please any info...

 

[BogusSVO]

Sounds like finely ground metal particles. When mixed with oil makes a paste.

You may want to cut open your oil filter and see if you have it in there.

When you rub it between your finger does it feel gritty? kind of like powdered sugar?

Did you use a good bit of moly lube? Like engine assembly lube? or the whole package of ARP lube?

That all should have washed away before you went to synthetic oil. But the detergent additives in the oil.

 

[95boostedmo]

How bad I'd it cause my car did the same thing. Not sure what caused it!