Replacement of the thermostat?

Its primary purpose is to control engine temperature. Here is a guide to help you step by step with instructions in the diagrams below to show you how on your car.

https://www.2carpros.com/articles/replace-thermostat

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

There was obviously an over heating problem when the last owner had it, removing the thermostat is not a answer for this, it may be as simple as a part blocked radiator, get it out and core cleaned first, back flushing will not be enough it should have a full core clean done first, hopefully this is all that it needs, fit a new thermostat housing as well flush the cooling system and the heater, start here.

Hi there,

If the thermostat was removed your engine temp would normally be well down and the heater not very hot. I would suspect a leaking heater core. You better have a pressure test done and keep an eye on the coolant level.

Mark (mhpautos)

It is located at the end of the upper radiator hose, where the hose meets the engine is the thermostat housing, remove the bolts and you will see the thermostat.

Thermostats are almost always located where the lower radiator hose attaches to the engine.

I stand corrected

Drain the cooling system.
On 3F-E engines, disconnect the 2 vacuum hoses from the Bimetal Vacuum Switching Valve (BVSV), the cold start injector time switch wire and the water temperature switch connector.
Unbolt the housing, then remove the water inlet with the hose attached. If there is not enough room to pull both housing and hose out, you may want to disconnect the hose first. On 3F-E engines, remove the clamp bolt for the ISC water bypass pipe. Make certain to remove the gasket with the water inlet. Some of it will probably stick to the housing and require scraping.
Remove the thermostat.

To install:

When installing a new thermostat always use a new gasket. Be sure that the thermostat is positioned with the spring down or into the housing. On 3VZ-E engines, the jiggle valve (looks like a small rivet in the edge of the thermostat) must be at the top or 12 o'clock position.
Install the water inlet. Install the bolts finger-tight until the inlet is positioned exactly. Tighten the bolts to 10-14 ft. Lbs. (13-19 Nm). Overtightening will break the ear off the housing and spoil your afternoon-don't do it.
Install the hoses and wire connectors removed for access. Make certain the coolant hoses are not kinked or twisted after installation. Do not overtighten the hose clamps.
Fill the cooling system with coolant.
Start the engine and check for leaks. Top off any fluid levels.

Hi there,

You may have a cracked thermostat housing, remove, clean & inspect, if in doubt replace as they are nor expensive, replace thermostat, flush coolant and replace the gasket, presser test when done to check for leaks.

Mark (mhpautos)

Sounds like the thermastat is sticking, did the mechanic put the same temperture thermastat back in the vehicle? There are ones of diferent temp settings, example there is a 160 and 180 most comon, check to see if there the coolant level is correct.