“Lada-Priora” is one of the cars of the “VAZ” family. And as a typical representative, there are some shortcomings that arise at the most inopportune moment. Inadequate heating of the engine in winter or overheating in the summer heat while in a traffic jam - all this can be caused by a malfunction of the cooling system.
Replacing the thermostat on the Prior is a simple task for any motorist.
Thermostat purpose
This small detail is of paramount importance. It is the thermostat that allows the engine to work in optimal temperature conditions. Being a part of the cooling system, it performs the function of a valve that does not allow the coolant to circulate in a large circle (through the radiator) until it reaches the operating temperature.
The cooling system has 2 circuits that are interconnected via a thermostat. The small circle allows you to warm up the engine as quickly as possible in cold weather. Until the coolant temperature rises to 70-75 degrees, the thermostat is completely closed. It begins to open slightly in this thermal gap and is fully open when it reaches 95 degrees.
As the valve opens, hot coolant is mixed into a large circle, where it, passing through the radiator, gives off part of the heat to the atmosphere. If the operating mode is violated, the “Prior” thermostat should be replaced.
Reasons for Failure
The operation of the thermostat largely depends on how soundly it is assembled. If a high-quality part is installed on the machine, and the owner uses good antifreeze and changes it in a timely manner, then the thermostat can last the entire life of the car.
Unfortunately, the coolant does not always comply with GOST, and the parts supplied to the conveyor pass quality control. All this leads to the fact that the replacement of the thermostat on the "Prior" becomes inevitable.
The main causes of failure are as follows:
- Depressurization of a brass flask in which wax is sealed. During operation, brass solder undergoes corrosion, as a result of which its integrity is violated. This malfunction manifests itself in the fact that the valve opens completely and is not able to close back. Antifreeze constantly runs in a large circle, and the engine cannot warm up to operating temperature.
- Foreign particles entering the thermostat. This happens if the coolant has not changed for a long time, and has also been diluted with water, and scale has occurred. In this case, the valve may jam in both open and closed positions. In the first case, warming up will take longer than usual, and in the second ICE it will overheat.
Diagnostic Methods
When the thermostat is working properly, the car engine heats up to operating temperature in 5-10 minutes at an ambient temperature of at least 0 degrees. If warming up takes longer, then making sure that the thermostat is the culprit is quite simple. To do this, you need:
- Start the engine and wait until the coolant temperature readings on the instrument panel are in the region of 85 degrees.
- Open the hood and find the pipe from the thermostat to the radiator. It should have approximately the same temperature as the other pipes of the cooling system. If it is much colder, then the valve is either closed or not fully open. This is a good reason to replace the Lada-Priory thermostat.
Symptoms
Even if you do not carry out diagnostics, you can suspect the presence of malfunctions of the thermostat during the operation of the car. They will manifest themselves as follows:
- The engine heats up for a long time.
- Heating the coolant to a temperature of 130 degrees and above.
- The sensor shows the temperature during a stop significantly higher than when driving at speed.
- The lower pipe of the thermostat begins to warm up immediately after starting the engine. This indicates that the valve does not close completely.
- The lower branch pipe is cold at a time when the temperature on the instrument panel approaches one hundred.
The last item reports a closed valve, unless the cooling fan is faulty, which does not require replacing the Priora thermostat.
DIY replacement
Before doing the work, you need to understand if there are any differences in replacing the thermostat on the “Prior” with 16 valves from the same model with 8 cells. Despite the difference in power, the differences in the engines are not significant. Both are based on the same cylinder block. Only the cylinder head and the gas distribution mechanism differ, and the assembly itself, in which the separation into small and large circles, is the same. This means that replacing the thermostat on the “Priora” 16 cells is no different, except that it needs to be removed with a decorative plastic cover that covers the engine.
To change the thermostat, you need:
- Drain antifreeze from the radiator. To do this, unscrew the tap at the bottom, and also remove the plug from the expansion tank. Tank for draining must be prepared at least 5 liters.
- Unscrew the clamp of the pipe going to the radiator and pull it off. A little more coolant will flow out, so you need to substitute a bottle for draining.
- Remove the opposite pipe in the same way.
- Remove 3 thermostat bolts with a hex wrench.
- Relocate from the old thermostat to a new sealing rubber ring, grease adjacent planes with silicone sealant.
- Reinstall the new thermostat and tighten the bolts.
- Put the pipes in place, after lubricating the seats on the thermostat with silicone sealant.
Additional tips
Before replacing the Priora thermostat, it makes sense to check the new one for operability. To do this, the item is placed in a pot of water.
Gradually heating the water, you need to monitor how the valve opens. If at a temperature close to boiling it is completely open, then it can be installed on the machine.
After replacing, do not forget to add antifreeze to the cooling system to the operating level indicated on the expansion tank. If a certain amount of coolant was spilled during draining, then you need to add the same color as the main liquid. Antifreezes of different colors do not combine.