I. Bad situation
Recently, a lot of bad information about white emulsion attached to the fuel filler cap of aerospace Mitsubishi 4A9 engine and oil emulsification appeared on the Internet.
Second, the real vehicle survey results
15 car was investigated. The emulsion is more or less attached to the filler cap of a single engine. Two of them have been decomposed and confirmed. There is no emulsifying phenomenon in the cylinder head cover of 1, and there is a small amount of emulsifying phenomenon in 1, but no water residue or emulsifying phenomenon is found in the engine oil. There is no abnormal wear on the camshaft and other parts. Ensure that there is no emulsifying phenomenon in the oil pan.
Fill the white emulsion in cap III. Formation mechanism of white latex
The steam produced by combustion enters the crankcase through the space between the piston and the cylinder wall together with the exhaust gas.
The exhaust gas flows into the intake manifold through the PCV valve, and then forms a combustible mixture to be burned in the cylinder.
In the cold state, the water vapor in the exhaust gas will condense in the lower temperature places (fuel filler cap, cylinder head cover, etc.). ) in the upper part of the engine.
This water is mixed with engine oil to form a white emulsion.
* Conditions for producing white latex: It can be used repeatedly when the engine stops before preheating after short-distance driving or short-time driving in winter.
* Because the oil temperature is still very low during short-distance driving in winter, the water in the emulsion cannot be evaporated and accumulated.
* This emulsification will be precipitated and reduced to steam with the increase of engine temperature after warm-up driving, and the emulsification will gradually decrease until it disappears.
(Real vehicle verification. After the engine temperature rises, the emulsion in the fuel filler cap is obviously reduced. )
Four. Oil-gas separator of aerospace Mitsubishi 4A9 engine
In engine design, it is generally necessary to set up an oil-gas separation device to filter the gas in the crankcase (including combustible gas, waste gas and oil mist particles), so that the combustible part of the mixed gas can re-enter the intake system to participate in combustion, and the oil with larger particles will re-condense and fall back to the oil pan, and at the same time achieve the effects of improving emissions and reducing oil consumption. This kind of oil-gas separation device is generally called "oil-gas separator".
In the structural design of the oil-gas separator of 4A9 engine, the patented technology of oil-gas separation unique to Aerospace Mitsubishi-labyrinth passage design is adopted. The oil-gas separator is arranged inside the engine (integrated with the engine valve cover), with good thermal insulation measures, which will not freeze, and water vapor will normally enter the intake system, thus avoiding oil emulsification. However, some engines set the oil-gas separator outside the engine, which will cause water vapor to enter the oil pan due to freezing. The mixing of steam and engine oil will cause the oil to emulsify, which will make the oil lose its lubricating effect and lead to engine damage.
5. There is no oil emulsification problem in aerospace Mitsubishi 4A9 engine.
The accumulation of emulsion in the filler cap and the emulsification of engine oil are completely different problems. It is normal for the filler cap to accumulate emulsion, which is found in engines of many well-known companies in the world and will not affect the use of engines. However, the emulsification of engine oil will make the engine oil lose its lubricating function and cause engine damage. This time, Mitsubishi Aerospace only accumulated emulsion on the fuel filler cap, and there was no oil emulsification problem reported on the Internet. There are more than 500,000 aerospace Mitsubishi 4A9 engines on the market now, and we have never received any complaints that the emulsification of the fuel filler cap affects the engine function, nor have we received any complaints about the emulsification of engine oil.
Conclusion of intransitive verbs
It is normal that white emulsion adheres to the engine fuel filler cap and cylinder head cover, especially when the temperature is low in winter. The emulsion is only attached to these parts, which will not cause oil emulsification, nor will it adversely affect the performance of the engine, so there is no problem in maintaining the current use.
The design of 4A9 series engine oil-gas separation device is safe and reliable, which has been proved in the international automobile market. Therefore, engine oil emulsifying phenomenon will not appear under normal use, and the lubrication function of the engine is reliable. Please feel free to use it. Shenyang Aerospace Mitsubishi Automobile Engine Manufacturing Co., Ltd.
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