How to replace thermost 1994 Toyota estema - 1994 Toyota Previa

In the USA the Estima is called Previa, and there may be some differences, depending on whether it has the 2.4L or a 2.2L engine or other options.

Labor Time for this job is One hour.

The water pump on the 2.4 Liter engine is accessed under the vehicle, very likely the same on any engine for these models.

Follow the radiator hoses to the engine until you find the water pump, which is near one of the drive axles.

The thermostat is bolted to the water pump with two bolts.

Drain the cooling system, then using a large pan under to catch any extra coolant when removing the thermostat housing.

Carefully clean the surfaces of both the thermostat housing and the water pump. [Check water pump for coolant seepage, which leaves a crusty beige or pink deposit. If so, replace the water pump.]



Install a new thermostat and gasket (Or O-ring).

Refill the coolant with the same coolant only if it looks clean.

I would also test the coolant to see what the PH is, which needs to be about 7.2 PH. (Coolant will turn acid over time, even when it looks okay.)

Make sure you put as much coolant back into the system as you removed.

Fully warm up the engine, and let it cool down before removing the radiator cap, then check for air in the system, topping up as needed.

The radiator needs to be full to the top.

Also check the overflow reservoir, which has level marks of Low and High, Never fill over the High mark. In the USA the Estima is called Previa, and there may be some differences, depending on whether it has the 2.4L or a 2.2L engine or other options.
Labor Time for this job is One hour.
The water pump on the 2.4 Liter engine is accessed under the vehicle, very likely the same on any engine for these models.
Follow the radiator hoses to the engine until you find the water pump, which is near one of the drive axles.
The thermostat is bolted to the water pump with two bolts.
Drain the cooling system, then using a large pan under to catch any extra coolant when removing the thermostat housing.
Carefully clean the surfaces of both the thermostat housing and the water pump. [Check water pump for coolant seepage, which leaves a crusty beige or pink deposit. If so, replace the water pump.]

Install a new thermostat and gasket (Or O-ring).
Refill the coolant with the same coolant only if it looks clean.
I would also test the coolant to see what the PH is, which needs to be about 7.2 PH. (Coolant will turn acid over time, even when it looks okay.)
Make sure you put as much coolant back into the system as you removed.
Fully warm up the engine, and let it cool down before removing the radiator cap, then check for air in the system, topping up as needed.
The radiator needs to be full to the top.
Also check the overflow reservoir, which has level marks of Low and High, Never fill over the High mark.