What is the abnormal noise problem of Nissan Sylphy engine?

There are many reasons for the abnormal sound of Sylphy engine caused by Pacific Auto Network, such as aging and damage of generator, air conditioning pump, circulating water pump, timing chain, various belt components and rubber pad of engine bracket. The specific reason can be judged by abnormal sound.

1, engine abnormal sound "dada" can be said to be a relatively common engine abnormal sound. Sometimes, after changing the engine oil, to be exact, after changing the engine oil with high viscosity, you can clearly hear the engine "beep" sound, which is mostly caused by high viscosity and increased internal resistance, and generally has no effect on the engine. But there is something wrong with the hydraulic tappet, which will make a "beep" sound. The application of hydraulic tappet is to automatically eliminate valve clearance and reduce engine noise. However, once the hydraulic tappet fails, the engine will have a serious "beep" sound

2, crisp knocking sound The so-called crisp knocking sound, such as knocking on the triangle, or knocking, is mostly due to engine knocking or knocking. Engine knocking is a common phenomenon, not necessarily a fault, but it may also indicate that the engine is in poor condition, but knocking on the cylinder is mostly caused by a fault. The possible causes of engine cylinder knocking are: the ignition angle is advanced, the piston compression is abnormal due to premature ignition, and the cylinder knocks, so the ignition angle needs to be adjusted at this time; The piston connecting rod is deformed or the cylinder is not round or pulled; The gap between piston and cylinder is too large; Poor engine oil causes parts to fail to form protective lubricating oil film; Carbon deposition or sludge inside the engine is extremely serious. Familiar with engine knocking. If the ignition angle is advanced or the engine compression is relatively large, and the octane number of the added fuel is too low, it is easy to produce engine knock. Whether knocking on the cylinder or knocking on the cylinder, in addition to the influence of abnormal noise, it is often accompanied by engine jitter.

3, the engine "hippo chef" abnormal sound In fact, the reason for this kind of engine abnormal sound is best to find, because the abnormal sound of "hippo chef" is mostly caused by the aging of each belt group of the engine, or the belt is too loose due to the problem of wheel tightening, resulting in abnormal friction noise and belt slipping. If there is an abnormal sound similar to "Little Chef Hippo", find the main belt groups and tensioners inside the engine, such as engine timing belt, generator belt, circulating water pump belt, air conditioning belt, booster pump belt, etc.