The engine water temperature is one of the parameters of the engine work, we are familiar with it, the most frustrating thing may be high temperature boiling, or the engine will have to overhaul, so many people think that the low water temperature is better, at ease, will not boil, in fact, this idea is very wrong.
Taking the data flow of Weichai WP10 EDC7 system as an example, when the water temperature is 20℃ and 70℃, the difference of fuel injection amount of engine injector is very obvious under three different working conditions. For example, at idle speed, the fuel injection amount is 20mg/H mg/ stroke at 20℃ and 11mg/H mg/ stroke at 70℃.The difference in fuel consumption nearly doubles.
Why is that?Because the function of the water temperature sensor is to measure the coolant temperature, for cold start, target idle calculation, but also for the correction of injection advance Angle, maximum power protection, etc.
As a very important correction signal, the engine computer accurately corrects the fuel injection amount through the temperature of coolant to meet the requirements of economy and emission.So the water temperature has a great impact on the amount of engine fuel injection.
In addition to the relationship between water temperature and oil consumption, there is also a very important thing is the relationship between water temperature and oil temperature. It is not difficult to see from the chart that water temperature and oil temperature are positively correlated. Too low temperature is bound to lead to poor oil mobility, which will lead to poor lubrication of the engine friction pairs and aggravated wear.
Therefore, some engines have cooling protection and warming functions. When the water temperature is lower than 50℃, ECU will lock the engine speed below 1580rpm to prevent the phenomenon of engine wear aggravated by large throttle crash. At the same time, some models will also open exhaust brake after starting to help the engine heat up quickly.
For the electronically controlled engine, too low temperature is not good, too high is not good.When the water temperature of the No.3 engine is too high (higher than 105℃), the engine will appear limping home mode and the engine speed will be limited to 1500rpm/min. If the water temperature signal is lost, the engine water temperature will be -40° by default. Think about the fuel injection volume at this time and find the fault immediately.
For the four models, the high temperature limit torque, rotating speed and does not affect the sensor signal to compensate the fault will limp home mode, if the water temperature signal phrase, will lead to a difficult cold start, emission, power down related fault, if the water temperature signal constant 0 degrees, the main reason may be a signal of short circuit, signal lines on the back line short circuit, fault or ECU.
It is recommended that you add antifreeze in strict accordance with the requirements of the manual, and it is forbidden to remove the thermostat of the engine. For the cooling fan and the radiator water tank, the cooling system pipeline should be checked frequently.Proper water temperature is beneficial to the efficient and stable operation of the engine.