Lubrication oil deterioration, worse, may lead to abnormal wear of engine, shorten the service life of the engine. There are many causes of oil deterioration:

一、空氣濾芯破損?？諝鉃V芯的作用是過濾進入發動機內部的空氣中的雜質，達到凈化空氣的作用?？諝鉃V芯有著一定的使用壽命，壽命長短與環境和材質相關?；覊m多和潮濕的地方容易縮短空氣濾芯的使用壽命，由于空氣濾芯大多數是由紙質壓縮而成，潮濕的環境會使得空氣濾芯壽命縮短。當空氣濾芯失去過濾效果或破損之后，空氣中的雜質非常容易進入發動機艙內部，細小的灰塵更加容易進入到機油當中?；覊m還可以通過氣缸進入曲軸箱導致機油的油泥和粘度增加，使機油潤滑性變差，甚至堵塞機油，導致發動機異常磨損。

A damaged, air filter. The air filter's role is to filter into the impurities inside the engine in the air, can achieve the function of purifying air. The air filter has certain service life, the length of life and the environment and related materials. Dust and damp places easy to shorten the service life of the air filter, air filter is because most by paper made of compressed, humid environment will make the air filter to shorten life. When the air filter filter effect of lost or damaged, the impurity in the air very easy access to the engine compartment inside, fine dust more easily into the oil. Dust can also enter the crankcase through the cylinder causes the oil sludge and viscosity increase, so that the oil lubricating property become worse or even blocked oil, lead to abnormal wear of engine.

二、機油遇水稀釋、乳化。氣缸墊損壞或其他原因使缸體或曲軸箱進水，當含水量超過0.1%時，機油添加的抗氧化劑、清凈分散劑等就會失效，因而加速機油的氧化過程。機油中含較多的水時，機油潤滑性變差，粘度下降，機油油膜抗摩擦效果差，輕則導致機油過早變質和機件生銹，重則引起發動機抱軸、燒瓦等嚴重機械事故。

Two, oil water dilution, emulsification. Damaged cylinder head gaskets or other reasons to make the cylinder or the crankcase water, when the water content is more than 0.1%, oil added antioxidant, dispersant and so on will fail, and thus accelerate the oxidation process of oil. Containing more oil in water, oil lubrication variation, decrease viscosity, oil film anti friction effect is poor, light to cause oil premature deterioration and parts of rust, weight is caused by engine axle, the tile burning and other serious mechanical accident.

三、燃燒室密封不嚴。如果活塞環或氣缸磨損后未及時發現，導致燃油長期竄入曲軸箱與機油接觸，長期的高溫致使機油變質、粘度下降、行成油膜的效果差等等。如此一來，油膜對活塞環與汽缸壁的潤滑和密封效果漸漸失效，活塞環與汽缸壁的摩擦不斷加大。長期如此，每當活塞做工一次，高溫火焰進入曲軸箱的次數增加，惡性循環不斷，導致曲軸箱內機油潤滑失效，最終導致燒瓦等問題出現。

Three, the combustion chamber is not tightly sealed. If the piston ring cylinder after wear or not in time, lead to fuel long-term into the crankcase and oil contact, long-term high temperature cause the oil deterioration, decrease viscosity, for oil film effect difference and so on. Thus, the lubricating oil film on piston ring and cylinder wall and the sealing effect fades, the friction of piston ring and cylinder wall increasing. So long, when the piston work time, high temperature flame into the number of the crankcase is increased, leading to a vicious circle continue, crankcase oil lubrication failure, ultimately causing the problem of burning tile etc..