Replacing the thermostat on a 1ZZ brand power unit may be required if characteristic malfunctions occur. The part may fail due to the use of poor quality antifreeze or mechanical damage. Let's take a closer look at how the 1ZZ-FE thermostat is replaced, providing a photo report.
Step-by-step description of replacement
The repair process begins with disconnecting the negative terminal from the battery. It is necessary to take into account the fact of further use of antifreeze. If replacing the antifreeze is not planned, then the coolant is first drained into a clean container. When filling in new antifreeze, the old one can be drained anywhere.
We dismantle the generator and thermostat
To change the thermostat on the 1ZZ engine, it is necessary to dismantle the generator, which will allow free access. To do this you will need to do the following:
Removing the generator
- remove the plastic decorative cover from the motor;
- loosen the generator drive belt tension adjusting bolt and remove the belt;
- Then the fixing fasteners of the generator are unscrewed.
After gaining access to the thermostat, we proceed to dismantle it. To do this you will need to do the following:
- using a socket head or a ten-socket wrench, unscrew the thermostat with the pipe. It is secured to the power unit with two nuts;
- Carefully lift the thermostat and remove it from its seat. If the coolant was not previously drained, then during this operation about three and a half liters will spill out;
- All that remains is to install the new part and perform the assembly process in reverse order.
Unscrew the pipe
Subtleties of selecting a suitable element and installation
When choosing a new thermostat, you need to pay attention to the length of the valve stem. It should be identical to the factory one. If the rod is shorter, it will not be able to completely shut off the small cooling circuit. This will cause the engine to operate at elevated temperatures. It is also necessary to take into account that the thermostat on the 1ZZ engine must open at a temperature of 88 degrees.
When installing a new element, an important point is to replace the rubber gasket. It is put on around the circumference of the valve, thanks to the presence of a central internal slot, before installing the part in the seat. After this, the remaining operations to replace the spare part are performed. Upon completion, you will need to fill in antifreeze. The volume will depend on the method of replacement, i.e. Has the coolant been drained?
Thermostat gasket
We expel air from the system
After replacing the 1ZZ thermostat, you will need to remove air from the cooling circuit. To do this, you will need to warm up the engine to the valve opening temperature, indicated directly on the part. Let the engine run with the coolant expansion tank cap open. At the same time, periodically pressing down the lower and upper pipes of the cooling system.
This will be accompanied by a gradual filling of the system with antifreeze. As it decreases, the required amount should be added. An indicator of the absence of air in the cooling circuit will be the cessation of a decrease in the level of antifreeze in the expansion tank, a stable engine temperature in the range from 83 to 95 degrees and a well-heated stove.
Good or bad
The thermostat response temperature on a Toyota Corolla, at which the fluid is released in a large circle, is 80°C; full opening occurs at 95°C. In this case, the liquid flows through the radiator.
To determine its functionality, you need to dismantle the device and place it in water. By using a thermometer and heating the liquid, you can accurately determine the valve's response temperature. This type of fault detection is the most reliable.
Why is a thermostat needed?
The device is designed to regulate the flow of antifreeze in the cooling circuit. When the engine is cold, the flow of antifreeze directly into the engine cooling jacket is blocked. This helps to quickly warm up the power unit. After reaching the operating temperature and to further maintain it, the coolant flow passes through the entire system circuit due to the opening of the valve.
Signs of malfunction
A thermostat malfunction is accompanied by the following symptoms:
- after starting the engine, the operating temperature takes a long time to rise;
- the motor heats up quickly and operates in overheating mode;
- the coolant in the lower pipe gains temperature after several minutes of engine operation, which indicates that the device valve is stuck in the open position;
- If, when the coolant temperature approaches boiling, the lower pipe remains cool, this indicates that the valve is stuck in the closed position.
It is very easy to check the functionality of a removed thermostat. It is necessary to place the part in water and heat it to the opening temperature of the valve. Temperature can be monitored using a thermometer placed in the water.
Thermostat design
We diagnose without removing the part
In order to establish the fact of a faulty thermostat, without removing it, you will need to monitor the operation of the cooling system using a temperature sensor. The most common malfunction of the part is accompanied by the valve sticking in the closed position. This leads to disruption of antifreeze cooling. It will be pressed exclusively through a small cooling circle. You can verify this by trying the pipes of the large and small cooling circle. The first one will have a much lower temperature compared to the second one. At the same time, in hot weather or when driving in traffic jams, the radiator cooling fan will operate almost constantly.
In this case, the power unit will overheat, which can lead to a violation of the geometry of the cylinder head. It cannot be restored and will need to be replaced.
Thermostat operating principle
Replacing the thermostat in Toyota Corolla
If the coolant overheats, one of the most likely causes of the problem may be a malfunction of the thermostat. As a rule, in cold weather there are no complaints about the operation of this device, but with the onset of heat, overheating occurs more and more often. In this case, replacing the thermostat in the Toyota Corolla is mandatory. The procedure can be performed independently if you have basic tools and skills.
Procedures after replacement
After replacing the thermostat, you should:
- Put it all together.
- Pour distilled water into the washer reservoir.
- Massage all hoses, and also start the power unit at idle speed.
- Wait for the fan to work and increase the speed.
- Cool the engine, drain the water and repeat the procedure again.
- At a minimum, this cycle should be repeated four times.
Features: approximately 2 liters of water will remain in the power unit, so you need to pour the same amount of LLC concentrate there, and also dilute it in a one-to-one ratio with antifreeze.
When replacing a thermostat, the following difficulties may arise: inability to drain the antifreeze in full. There may also be a problem with removing the generator: the bottom bolt is weak (perhaps the problem is in the thread locker). To prevent this problem from recurring again and again, the generator mounting element must be lubricated.
Symptoms of a problem
On Toyota Corolla E150 cars, the mechanism responsible for warming up the interior, engine, and speed stability may fail. Signs that the thermostat is not working include:
Replacing the thermostat in Toyota Dubrovka
Our technicians have been certified and carry out activities in accordance with the manufacturer’s recommendations. Before proceeding with them, they carry out diagnostics that allow them to accurately determine the cause. Thus, we save car owners time and optimize their costs.
The technical service has dealer-level diagnostic and repair equipment, as well as its own spare parts warehouse. We cooperate with trusted suppliers and purchase them at wholesale prices, so our customers have them available at a cost below the dealer price.
The price of the service is calculated individually, depending on the complexity of the work. You can find out preliminary figures in the price list in this section of the site or by contacting our operators. Order a thermostat replacement from professionals: +7 (495) 532-45-05!
How to change the thermostat on a Toyota Corolla
Coolant is toxic, so be careful when handling. When starting the engine, the expansion tank cap must be closed.
Screw the reservoir cap tightly. The cooling system is under pressure when the engine is running, so coolant may leak from under a loosely tightened plug. Place the car on a level surface 2.
Remove the lower engine splash guards 3. Turn counterclockwise. Place a container under the drain valve of the radiator of the cooling system located in the lower radiator tank, unscrew the drain valve plug two or three turns and drain the liquid.
Place a container under the cooling system drain valve located on the left side of the cylinder block, unscrew the drain valve plug two or three turns and drain the liquid. Hand tighten the plugs of both drain valves. Flush the cooling system by filling it with water through the filler neck of the tank.
Start the engine how to replace a thermostat on a Toyota Corolla 2007 and let it run until the electric fan turns on. Like this: When installing, observe two conditions: Thus, the housing does not block the channel to the stove.
Replacing and repairing the thermostat on a Toyota Corolla: step-by-step instructions
The car does not work properly, gasoline consumption increases, the heater blows cool air. In a word, complete discomfort. It will be worse if the thermostat does not open.
The car begins to warm up, the antifreeze goes into the expansion tank, then comes out of the tank. That is, as they say, the machine boiled.
Replacing the thermostat in Toyota Corolla
If this happens in the summer and on the road, experienced drivers know that they need to turn the heater on full mode and at the highest temperature. You can lower the glass on the windows so as not to feel the effect of the steam room.
We unscrew the thermostat cover - two small nuts on the cover were removed without disconnecting the temperature sensor connector and the pipe to the radiator. I had to remove the wire from the knock sensor. We take out the old thermostat and the gasket if it is stuck there.
