1. Butter when installing the cylinder head gasket
Some repairers prefer to apply a layer of butter on the cylinder head when installing the cylinder head gasket, which is considered to increase the engine's tightness. As everyone knows, this is not only useless, but harmful. It is well known that the cylinder head gasket is an important sealing material between the engine block and the cylinder head of the automobile. It not only requires strict sealing of the high temperature and high pressure gas generated in the cylinder, but also must seal the pressure and flow rate through the cylinder head and the cylinder body. Cooling water and oil, it is required to pay special attention to the quality of the seal when disassembling the cylinder head gasket.
If butter is applied to the cylinder head gasket, when the cylinder head bolts are tightened, a part of the butter will be squeezed into the cylinder water channel and the oil passage. When the butter remaining between the cylinder heads is working in the cylinder, some of the oil will flow into the cylinder due to the high temperature. In another part, the carbon deposits are stored on the joint surface of the cylinder block and the cylinder head. Under the action of high pressure and high temperature, the cylinder head gasket is easily broken down or burned, causing the engine to leak. Therefore, do not apply butter when installing the cylinder head gasket.
2. Diesel vehicles use gasoline engine oil
The oil is divided into gasoline engine oil and diesel engine oil. Although gasoline engines and diesel engines also work under high temperature, high pressure, high speed and high load conditions, there is still a big difference between the two. The compression ratio of the diesel engine is more than twice that of the gasoline engine. The main parts are much more affected by the high temperature and high pressure than the gasoline engine, so some parts are made of different materials. For example, the gasoline engine main shaft bush and the connecting rod bearing bush can be made of babbitt alloy with soft material and good corrosion resistance, while the bearing bush of the diesel engine must be made of high-performance materials such as lead bronze or lead alloy, but the corrosion resistance of these materials Poor performance. For this reason, in the refining process of diesel engine oil, more anti-corrosion agent should be added, so that a protective film can be formed on the surface of the bearing pad to reduce the corrosion of the bearing bush and improve the wear resistance. Since the gasoline engine oil does not have such a preservative, if it is added to the diesel engine, the bearing bush is prone to spots, pits and even the unfavorable consequences of peeling off during use, and the oil will quickly become dirty and cause the shaft to burn. The accident occurred. In addition, the sulfur content of diesel oil is larger than that of gasoline. This harmful substance will form sulfuric acid or sulfurous acid during the combustion process, and together with the high-temperature and high-pressure exhaust gas, it will enter the oil sump to accelerate the oxidation and deterioration of the oil, so the diesel engine oil is refined. Some anti-oxidation additives need to be added during the process to make the oil alkaline. If there is acid gas intrusion, it can play a certain neutralization effect, so that the oil does not oxidize and deteriorate too quickly. The gasoline engine oil does not add this additive because it is neutral. If it is used in a diesel engine, it will quickly deteriorate due to the corrosion of the above acid gas. Therefore, do not use gasoline engine oil to fill the diesel engine.
3. Domestic cars blindly use imported engine oil Some car owners believe that imported oil must be better than domestically produced oil, so imported oil is used in domestic cars, especially new ones. As everyone knows, this is often not worth the candle, there will be many ills. For example, most imported oils have low viscosity and cannot meet the requirements of domestic vehicles for oil viscosity. In addition, the materials of various matching parts of domestic engines are more heated than the imported ones, and most domestically produced car engines do not have oil radiators. If blind imported oil is used, the engine will be too thin at normal working temperature. The oil pressure is low, and even the specified working pressure is not reached, which can not meet the needs of normal lubrication, and the wear of the engine is intensified.
4. No oil is added when assembling the oil pump When the repaired oil pump is installed on the vehicle, if the oil is not added to the oil pump gear chamber, the oil pump will not pump oil, causing accidents such as burning of tiles. Because the gear oil pump relies on the small matching clearance between the gear and the inner wall of the housing, and the correct matching clearance between the gears to generate suction. If the oil pump is not installed or the oil is not supplied to the gear chamber after the oil pump is installed, the oil pump cannot generate enough suction. This is more pronounced for geared oil pumps with some wear and tear. Therefore, don't forget to add oil to the gear chamber when installing the oil pump.
5. Blackening of the oil is the deterioration of the oil Engine oil works under harsh conditions and is prone to oxidative deterioration, producing acidic substances and stacking polymer deposits, which destroys lubrication. In addition, the intrusion of the burned exhaust gas into the crankcase also promotes oxidative deterioration of the oil. Therefore, after a certain period of time, the oil usually deteriorates and loses its proper lubrication. However, with the continuous improvement of the quality of lubricating oil, especially the promotion and use of thickened oil, the blackening of the oil does not necessarily mean that the oil has deteriorated. This is because the clean dispersant added to the thickened oil disperses the deposits on the parts in the oil, making the oil black. Whether it is deteriorating, it is necessary to carry out tests on various indicators and implement regular oil changes to reduce unnecessary waste. If the engine oil with engine protection agent such as YYl02 is added, it will also be black after a certain period of use. Therefore, the blackening of the oil does not mean that the oil has deteriorated.
6. Blindly choosing lubricants
Lubricating oil acts to lubricate, cool, clean and seal. The quality of the lubricating oil is directly related to the length of the engine life, so do not blindly choose the engine oil. New cars require very strict lubricants. What lubricants to use, when to replace them, and how to replace them should be carried out in accordance with the manufacturer's regulations.
When selecting engine oil, pay attention to both the quality level and the viscosity level. First, the performance level should be selected according to the compression ratio, displacement, etc.; then the viscosity level should be selected according to the temperature and load. When choosing the quality of the oil, it should be high and not low. Good quality oils ensure good engine lubrication, reduced wear, extended engine life, extended oil change intervals, and reduced frequency and difficulty of maintenance and repair. When selecting the viscosity of the oil, in addition to the temperature conditions, under the conditions of ensuring engine lubrication and sealing, try to use low viscosity oil to save fuel.
7. Use multi-viscosity lubricants best
Multi-viscosity lubricants (also known as multi-grade lubricants) have the properties of light oil at low temperatures and heavy oils at high temperatures. Where multi-grade oils are recommended, a multi-grade oil can be substituted. A variety of single grade oils. Although multi-grade oils can meet extremely cold and warm seasons and heavy-duty engine oils, especially those that do not have difficulty in starting in cold weather, it is usually recommended to use a single viscosity lubricant to help the engine lubricate and extend. Engine life. Therefore, do not think that it is best to use multi-viscosity lubricants.
8. Mixed use of engine oil
For all kinds of lubricating oils, the base oils are the same except for the viscosity grades. The only difference is the variety and quantity of the added components. Therefore, the type and quality level of the lubricant are generally classified according to the variety and quantity of the added components. Lubricating oils with different types of additives cannot be mixed. Otherwise, the additives in the oil may react chemically and damage the lubricating oil. With the continuous improvement of additives and their formulations, some general-purpose oils have been developed. For example, lubricating oils such as QE/CC and QF/CD for gasoline engines and diesel engines. They can be used within the indicated levels. Therefore, whether the lubricating oil can be mixed or not, according to the requirements of the manual, comprehensively compare the name, variety and grade of the oil, reasonably select the use level and the appropriate grade, and cannot blindly use the risk, and can not be mixed. 9. Lubricating oil is only added and not replaced.
Many car owners only pay attention to check the oil quantity of the lubricating oil, and add it according to the standard, without paying attention to checking the quality of the lubricating oil, ignoring the replacement of the already-changing oil, which causes some moving parts of the engine to always be in poor condition. Operates in a lubricated environment to accelerate wear on all lubricated parts. Therefore, in general, when the car is driving 3,500 to 5,000 km, the engine oil should be replaced.
November 06, 2020
