I was cleaning my thermostat with brake clean and a metal washer (a small flat washer that is smaller than a fingertip if it means anything) until the washer slipped out of my finger and I believe it went into the intake where the thermostat housing is bolted to. I looked inside with a flashlight and could not see it. Then I saw a large hole that leads to the cylinder head on the passenger side. I am thinking it may have went there? I’m going to rent a borescope and look inside, but if I don’t see it in there, is there anywhere else in the engine it can go to after falling inside there? I had the intake covered with rags but somehow the washer managed to slip through.