Hello all - seeking advice. I took my car's IAC valve out the other day. It was almost completely black (dry black, not wet oily). It's a 2001 2.5, about 94000 miles, recently had the HG and exhaust done. I've cleaned the valve and reinstalled, but would like any ideas on what causes such blackness? It was also very black inside the throttle body, which I wiped out with paper towel.