I am looking at a 2000 LX470 with ~106k miles. In looking at the service history there is an event at 57k miles that states:
-CUSTOMER STATES VEH OVERHEATS AND IT TAKES ONLY ABOUR 5 MINS TO GO OVER MAX HEAT ON GAUGE. T-STAT STUCK CLOSED INSTALLED NEW T-STAT COOLANT TEMP IS NORMAL. FOUND P0115...