Yes, the thermostat is the water pump / timing belt job on these. In the middle at the front of the engine block.
The quickest way is to remove bumper, front panel with rads on one side (so You don't need to disconnect aircon rad) and it's a pretty simple job. Just timing tool for camshafts recommended.
If the engine gets up to ~90C them it will be air in the pipes or matrix. I would bet on air
