over-heating problem resolved

Volvo MD7A heating problem solved with replacement of the thermostat and removal of a small rubber plug that mechanics suspect was floating around in the engine for awhile and finally got stuck in the end of the raw water inlet to the thermostat housing. Take a look at what was left of the thermostat. I should have thought to inspect the thermostat after I purchased last year but it seemed to run in mid-range on the gauge so I was not concerned........Photos attached..... Bob Connell Jollygood! Cal 31 #59 Olympia, WA