Thermostat failure diagnosis method in the winter, you may find the excavator thermostat not make more and more, becomes not so sensitive, it may be a thermostat is out of order, but do you know the principle of thermostat?
We first introduce the thermostat!
Principle of thermostat thermostat is according to the coolant temperature change and to automatically adjust the water flow into a radiator, at the same time will also change the water cycle, namely we often say & other;
Large cycle & throughout;
And & other
Minor cycle & throughout;
So to adjust the heat capacity of the cooling system, thus ensure the engine work in the appropriate temperature range.
Thermostat failure after the performance of the thermostat general problems can lead to the main valve opens too late or too early.
If open too late will cause the engine overheating;
If open early, will make the engine preheating time extended, the engine temperature is too low, which affects performance.
In simple terms, is the performance after the thermostat failure is the water temperature is high or low temperature.
Judgment of thermostat failure of thermostat failure is generally rely on experience to diagnose, so how to judge the thermostat failure?
Then the author introduces several methods for you.
A, check after the engine starting.
First to open the cooling water tank and water flap, to see whether the water cooling tank of water flow phenomenon, if there is no water flow means thermostat has a foreign body damage or card to switch between the main valve.
Second, the engine work after a period of time for inspection.
When water thermometer instructions below 70 ℃, and see whether there is water flow, water tank radiator inlet line if hot water temperature, cooling water may be premature large cycle, the time of probe is the main valve fault that there might be a closed lax.
When the water temperature higher than 80 ℃, through the tank cover to see if the water flow, if there is a fault, not flow thermostat needs replacement.
Three, to observe water thermometer, see if water thermometer display abnormal.
When the water temperature below 80 ℃, the water thermometer, generally at the beginning of the engine operation, water temperature table pointer to rise soon.
And when the water temperature higher than 80 ℃, water temperature table pointer speed is slow, this suggests that the thermostat is normal.
If the water temperature has been increased quickly, especially when the tank pressure to a certain extent, suddenly boiling water overflow, this suggests that the main valve is binding or probe is failures.
Four, feel with the hand temperature method.
Open the radiator and water flap and waterproof switch, with the hand to feel the temperature of the coolant, if hot, then normal thermostat;
If water inlet water temperature is low, the radiator water chamber inlet line without coolant flow, or flow rarely, suggests that there is something wrong with the thermostat main valve, shall promptly carry out repairs at this time.
In real BBS, also has a lot of net friend gives information about the thermostat, let's take a look at.
Machine friends 1: the thermostat is the switch of pulmonary circulation and systemic circulation, the engine temperature, water temperature is lower than the thermostat open it closed circulation, open a small cycle, make the engine water temperature rising rapidly, in order to make the engine quickly water temperature to normal operating temperature.
After the water temperature thermostat open temperature thermostat opens, part of the systemic circulation of hot water through the heat dissipation, part through the pulmonary circulation.
When temperature to the thermostat is wide open, the minor cycle closed, large cycle full open, in order to maintain the water temperature in the normal operating temperature range of seventy to ninety degrees.
After remove the thermostat, in the summer, some without circulation cooling water, make the engine water temperature is too high, in the winter, because there are part of the water through the systemic circulation, make the engine temperature is very difficult to rise quickly, launch a pilot work time at low temperature, adverse to the engine.
Machine friends 2: if remove the thermostat, it is best to chocked up with small circulating water.
There may be some small cycle, or circulating water caused by high temperature.
In general, remove the thermostat is to reduce the water temperature.
But the northern winter warm up engine speed will slowly, preheating is not good, long time work at low temperature, engine speed machine wear.
Southern summer can tear down, but barring the tiny, cold to mount;
The north it is best not to hurt!
This paper extract network, such as abuse delete.