Will installing warm water valve not affect engine cooling?
1 inspection method for circulating flow condition of coolant
This method is a traditional method and the most basic one. It is also suitable for the maintenance of general automobile cooling system and modern automobile cooling system. When maintaining the cooling system, first check whether all components of the system are damaged or leaked. At the same time, the V-belt driven by the water pump can not be ignored, and the pressure generated by the water pump drives the coolant to circulate in the system. Some unnecessary constraints in the radiator, hose or engine will hinder the circulating flow of coolant. The basic method to check its condition is to check whether there are cold spots in the system.
Let the engine run until it is fully warmed up, then turn off the engine until the thermostat is turned on, put your hand in the center of the radiator, and then move it from the water inlet chamber of the radiator to the water outlet chamber to sense whether there is a cold spot. Check all hoses in the same way. The temperature on the radiator and soft water pipe should be evenly distributed. If the temperature at one point is lower than that at other places, it means that the coolant in the cooling system is restricted or blocked.
This is a common method, but in many vehicles produced now, some parts of the cooling system are often inaccessible by hand. In this case, a more accurate way to check the uneven temperature distribution is to use a non-contact optical thermometer. When measuring, aim the laser point at the test area and read the accurate temperature value of the area on the thermometer display screen.
2 System pressure inspection method
If there is a small leak or internal leak in the cooling system, it may not be found by some simple inspection methods. If these phenomena are under certain pressure, these loopholes will be exposed. On the other hand, this pressure testing method can also be used to check the system's ability to maintain pressure, which is very important for the temperature control of the cooling system. The pressure test equipment includes a small air pump with a meter, a short hose and some adapters, which can match the water injection diameter and end cover of various radiators. If the ge cover of the radiator is not well sealed, there will be pressure leakage here, so don't forget to test the tightness of the radiator cover when testing. Remove the radiator cover from the radiator; And then connected to the adapter; At the same time, keep the radiator cover moist, which is helpful to improve the sealing between the radiator cover and the adapter; Run the air pump slowly until the reading on the meter no longer increases. The pressure reading on this meter is the opening pressure of the safety valve on the radiator cover. Repeat it 2~3 times to check the correctness of the result.
Then check the radiator for leaks. Radiators are divided into longitudinal flow type and cross flow type. When the engine is not started, connect the pressure equipment and then connect the air pump until the reading on the meter reaches the specified pressure. The reading on the meter should be kept for at least two minutes. If the pressure drops, start the air pump to keep the system at a certain pressure, so as to check the leakage of the radiator.
Leakage in the cooling system is sometimes difficult to find. Pinhole-sized holes require high pressure to be exposed. If the system is pressurized to 100-250kPa for inspection, the location of most leaks can be determined. When the engine is turned off, a lot of air will accumulate where there is air leakage, and this air leakage is difficult to find. When the system is pressurized, soapy water solution can be used to check the leakage points in suspicious areas, such as soft water pipe joints.
3 cooling system "trapped gas" solution
One of the biggest problems of modern cooling system is that air often stays in the cooling system. Air or other gases may leak out through the water pump inlet, hose connection or combustion chamber and enter the cooling system. Air may also enter the cooling system through the damaged sealing ring on the pump shaft. Because the water pump inlet can also work under the action of the reverse force generated by centrifugal force, air can be sucked into the cooling system through the damaged sealing ring on the water pump shaft at this time. This invisible air inlet is difficult to find, but if the possibility of leakage in other parts of the cooling system is ruled out and the system still has leakage problems, then it is time to remove the water pump and check whether the sealing ring on the pump shaft has caused leakage.
People do not discharge and inject coolant according to standard procedures, which is the most common reason for air in the cooling system. The general process of replacing coolant is: open the water pipe to let the original coolant flow out, then inject new coolant, start the engine until it is fully warmed up, and continue to add coolant after the thermostat automatically opens. In fact, however, changing the coolant is not that simple. Many engines need special exhaust devices, and some cooling systems are equipped with special exhaust valves. Circulator makes it easier to replenish coolant and reduces many exhaust problems when replacing coolant. However, if there is no such device, you can consult the authoritative automobile manual, and most automobile exhaust procedures can be found in the automobile manual.
4 change the coolant in time
Even the so-called "permanent" antifreeze cannot be permanent. For example, the long-life coolant, which is replaced every five years, has been put into the market for several years, and the system using this coolant should also be maintained. After basic inspection, we found that the coolant had been polluted by rust, oil and dust. Although the surface of the coolant still looks intact, its effectiveness may have been greatly reduced.
Density is a good standard to measure the anti-freezing ability of engine coolant. The density of engine coolant should be higher than that of pure water (1. Okg/L)。 The greater the density of coolant, the stronger its anti-freezing ability.
Take some coolant from the radiator or overflow tank as a sample, and then pour it into the liquid density meter. There are several kinds of liquid density meters in the market, all of which are equipped with conversion tables to convert the corresponding density readings into the corresponding antifreeze temperature grades. After years of use, the material of cylinder gasket will lose strength or collapse due to the constant change of temperature. However, the fire effect of most cylinder head gaskets starts from the hot spots around the engine combustion chamber. The cooling liquid circulation is poor, the system pressure is not suitable, and the system blades interact with the existing air to form steam bubbles in the water jacket of the combustion chamber. Because steam is not easy to transfer heat, the engine has local overheating near the cylinder head gasket. Overheating will reduce the performance of the cylinder gasket, and the high-pressure gas produced by combustion in the combustion chamber will soon tear the cylinder gasket through high temperature.
If there is a problem with the cylinder gasket, start the engine first and let it run fully until the thermostat door is opened manually. Then start to check and repair the fault. If bubbles appear at the radiator injection neck or vortex appears here, it means that the pressure of the cooling system is too high, and this pressure increase is likely to be the leakage of the engine combustion chamber.
Check whether there is pressure drop in the cooling system by using the above pressure test method. Air leakage from cylinder gasket is the most common leakage. The pressure test works in two ways, and then the low pressure test is carried out on the cylinder that may leak. The air pressure in the cylinder is lower than normal, and there are bubbles in the radiator, which are all strong proofs.
Most problems in the cooling system are caused by the loss of coolant or both. If we check and repair the faults of the cooling system, and the operation conforms to the working principle and basic physical logic of the cooling system, then we will find out the causes and components that cause the system faults. Make the solution of the problem get twice the result with half the effort, save costs and improve work efficiency.