Why does the valve of FAW Jiabao V70 cool car ring? I hope the water temperature rises.

At present, the engine valve train used in vehicles has two structures, one is that there is no automatic valve clearance adjustment mechanism; First of all, it has an automatic hydraulic valve clearance adjustment mechanism;

It is normal for the first type of engine to have the above situation, which is caused by the influence of thermal expansion and cold contraction of the valve transmission mechanism. In general, the valve clearance of this engine must be reserved (between 0. 1-0.25mm). If this gap is not left, the valve will not be closed normally when the engine is started, because the rod of the valve transmission mechanism is the principle of thermal expansion and cold contraction. Therefore, it is normal that the cold car has a slight noise and the hot car has no phenomenon. But if the noise is loud, it is time to adjust the valve clearance.

In the second case, the valve train equipped with hydraulic tappets, because the hydraulic tappets have engine oil as the transmission medium, will automatically fill the engine oil in the hydraulic tappets with the change of valve clearance, thus realizing a gapless valve structure, and of course, there will be no noise. However, when the hydraulic tappet has some problems, such as improper fit clearance and blocked oil inlet, it will make abnormal sound due to untimely oil inlet or hydraulic oil leakage. Of course, due to manufacturing accuracy and other problems, it is normal for vehicles to park for too long, and there is noise after the cold car starts. This is because of water leakage and other reasons. When the hydraulic tappet was just started, there was not enough engine oil to supplement it, resulting in valve clearance and noise, which disappeared after engine oil was supplemented. If there is still noise for a long time after starting, you should go to the service station to check whether there is any problem with the hydraulic tappet.