Recently, the temperature across the country has dropped sharply. With the temperature in some areas gradually breaking below 0 degrees Celsius, the diesel engine has reached the time when it is necessary to refill the winter oil. So what measures and points should be taken when using diesel oil in winter diesel engines?
Method & Step
Select the oil viscosity according to the working environment temperature
Diesel engine oil is classified according to two different classification methods: different viscosity grades (low temperature viscosity grade and high temperature viscosity grade) and oil quality grade. The viscosity grade is based on the rating standard of the American Society of Automotive Engineers (SAE). The engine oil quality grade is based on the American Petroleum Institute (API) rating standard. The domestic market generally uses viscosity grades to distinguish.
Viscosity grade is generally marked by the working temperature range that the oil can adapt to. For example: SAE40, SAE50, such as engine oil, means summer oil, the applicable temperature is 40 ℃, only used in summer, can not be used in winter; and SAE15W-40, SAE5W-40, this kind of engine oil, said it is universal The engine oil can be used normally at an ambient temperature of minus 30 ℃ to 40 ℃.
"W" in the engine oil label indicates winter (winter), the smaller the number in front of it, the better the low temperature fluidity of the engine oil, the lower the ambient temperature that can be used, and the better the engine's protection ability during cold start; The number behind "W" (behind a horizontal line) is an indicator of the high temperature resistance of the engine oil. The larger the value, the better the protection performance of the engine oil at high temperatures.
Choose the right oil viscosity has a direct impact on the performance of the engine, mainly reflected in the following two points:
(1) Although the oil with high viscosity has strong adhesion, the high viscosity will increase the internal load of the engine and cause a large internal power loss of the engine.
(2) Although the oil with low viscosity can reduce the wear and friction of the moving parts and improve the self-cleaning ability of the engine, but because of the low viscosity of the oil, even if the oil reaches the working temperature, the oil pressure is too low due to too thin oil, Failure to reach the working pressure will in turn cause insufficient lubrication and aggravate the wear of the engine. It is very likely that the engine is pulling cylinders and holding shoes, causing damage.
Here is an example to explain how to choose the right winter oil.
For colder regions like Beijing, add commonly used 15W-40 general motor oil (used when the ambient temperature is between minus 15 degrees and 40 degrees); for northeast China and other cold regions, you need to consider changing the label when entering winter Higher oil, such as: 10W-30 grade oil (used when the ambient temperature is below 10 degrees to 30 degrees below zero), or higher grade oil; and for the warmer areas in the south, you can consider according to local actual conditions Do you need to change the oil with a different label?
Select engine oil quality according to engine grade
At this stage, Chinese construction machinery manufacturers mostly use four-stroke turbocharged direct injection engines to assemble on their own equipment, and the emission standards only reach the second stage of emissions (ie Tier-2). Models equipped with such engines can use CF-4 grade oil to ensure normal use.
For diesel engine oils used in construction machinery, such as CF-4 grade oils, where C represents diesel engine special oil; F represents quality grade, each incremental letter, the performance of the engine oil will be better than the former, the lower the letter , The higher the quality level; "-4" indicates the engine oil performance improvement level. In the same level of engine oil, the larger the number, the better the quality.
For imported models, when selecting engine oil, you need to choose according to their engine oil supply method: direct injection supercharged engine can use CF-4 grade oil; electric injection supercharged engine needs to choose CH-4 grade or higher Grade oil to ensure the normal operation of the engine.
At the same time, most domestic construction machinery manufacturers use engines that do not use an exhaust gas recirculation system, or EGR. Therefore, the selection of diesel oil of CF-4 or CH-4 grade can meet the requirements of engine oil for construction machinery on the domestic market at this stage.
Special reminder: If the equipment purchased by the user is not directly sold to the Chinese market, then it is necessary to accurately judge the emission standards of the engine to select the required oil.
Since the models sold by construction machinery manufacturers to countries and other regions in the world have widely used the diesel engines of the third-stage emission standards, users must choose the appropriate quality grade of engine oil when choosing the engine oil to avoid The engine is hazardous. Precautions for oil filling
For anyone, filling oil is a simple matter, but there are a few things to note when filling oil.
1. It is strictly forbidden to mix engine oils with different labels.
In the winter, if the equipment needs to be replaced with a different type of engine oil, the engine oil must be completely drained before adding the new type of engine oil.
2. It is strictly forbidden to mix engine oils of different brands.
Different brands of engine oils will use different additive formulas. Mixed use may produce chemical reactions, reduce the performance of the engine oil, and affect the normal operation of the engine.
3. Heat engine oil.
Before replacing the old engine oil, you need to start the engine and run it at idle speed for a certain time to make the engine oil temperature close to the operating temperature, and then replace the old engine oil.
There may be many friends who don't understand the heat engine oil. Actually, it is because: due to the high fluidity of the heat engine oil, impurities attached to the surface of the body can be effectively cleaned. The oil released by this method will effectively reduce the amount of foreign particles remaining in the engine, reduce the wear of the engine, and ensure the efficient operation of the engine. In addition, the hot engine oil is more easily discharged completely, reducing the residue of old oil.
4. Do not "add more" when refilling the engine oil.
Generally speaking, it is better to add oil to the center line of the oil scale a little bit (about 3cm). Excessive oil will increase the resistance to crankshaft rotation. Moreover, due to the coming of winter, low temperature will increase the viscosity of the engine oil, and excessive crankshaft rotation resistance will reduce the engine power, resulting in weak equipment movement.
In addition, the excessive addition of oil will increase the possibility of oil running up, which is easy to cause an increase in oil consumption (commonly known as blue smoke), increase the carbon deposit in the combustion chamber, and increase the probability of deflagration, affecting the normal operation of the engine Unnecessary engine wear. Therefore, the addition of engine oil must be added to the specified position, that is, the middle of the scale of the dipstick is slightly higher, which is enough.
Furthermore, it is necessary to clean the filling port and the oil drum before adding oil to prevent impurities from entering the engine body. After filling the engine oil, we also need to wipe the spilled engine oil clean to maintain a good working environment for the engine. These are the details that everyone needs to pay attention to when performing daily maintenance on the engine.
Above we briefly introduced the engine oil maintenance part of the engine in winter. If the machine can be well maintained and maintained in the cold winter, whether it is during winter construction or long-term parking during the winter break, we will There are counts in my heart, rest assured of winter.
