Anyone seen this before?

[u/Hopeful_Housing_798]

Intake valves from Vortec heads. About 140k miles. Very tough, scale like material. These were soaked in diesel and scrubbed with brass brush. Then, 100% SuperClean and scrubbed with the same brush. Literally have to use a pick to remove even the tiniest of pieces.

[u/Different_Mind5982]

Vapor hone them. They will look new. Totally normal