How old is your truck? When was the last time either the coolant or the thermostat have been changed verifiably?
If you don’t know, then the answer is above.
If you do, then proceed with how Toyota recommends servicing or when your thermostat was changed.
What year? What model Land Cruiser sir?
It’s a ‘91 HZJ77. I’ve had it for about two years, and I’ve never flushed the coolant nor changed the thermostat. I got it off an auction on the Mainland, so I have zero idea of its history or anything about the previous owner. Sounds like I’ve got a plan for this weekend now!