OTTO Excavator Spare Parts Tcm 4Jg2 Thermostat Seat 8970186640 897018-6640 8-97018664-0 For Isuzu Thermostat Seat part 8970186640 (also 897018-6640, 8-97018664-0) for OTTO excavators with Isuzu 4JG2 engines. OEM replacement component for cooling system regulation.