Author: Brother Car Picker
Question: How do you tell if a car has used fake oil?
First, observe the oil gauge.
If you find that there are obvious blackened marks on the oil gauge, then this car has used fake oil.
Because the genuine oil has a parameter is the resistance to high temperature evaporation performance, its laboratory standard simple explanation is to heat the oil for an hour at 250 degrees Celsius, the quality loss of the oil should be less than 15% to be qualified, and some more stringent oil standards are even less than 13% of the percent.
Therefore, the high temperature evaporation of genuine engine oil is relatively small, and the base oil of genuine engine oil will be relatively pure and the level is relatively high.
As a part that is inserted directly into the engine oil pan and does not participate in any metal friction, even if the oil vapor of the genuine oil has been infused, it has changed from silver to golden yellow at most.
The fake oil can not have a pure base oil, and there is no high temperature evaporation performance to speak of, so the oil vapor it produces in the engine is black and more.
After using the fake oil two or three times, the oil gauge will be blackened, especially at the bottom of the oil gauge. Some used car dealers will specially wipe the grease gauge of the used car very clean, and then take it out to sell, so if only looking at the oil gauge is not enough, you also need to look at the second place.
Second, observe the reverse side of the oil cover.
Under normal circumstances, after opening the lid, if the reverse side of the lid is completely clean, there is only a little bit of liquid oil left behind after the oil vapor solidifies, or there is only a little emulsified oil, which is similar to the color and state of the latte, which is normal and does not affect the normal use of the engine.
However, if you see the black sludge that can be directly removed on the reverse side of the cover, then the eight achievements of this engine are fake oil that has been used for a long time.
Third, observe the surface of the camshaft.
The same principle, through the oil filling port, look inside, the valve chamber cover is the upper layer of the engine cylinder head, and now most family cars use camshaft overhead technology, so you can see the camshaft surface of the engine, or see the official chain of the engine.
But whether it is a camshaft or a formal chain, they should be metallic silver-white, and the car with a relatively long mileage should be at least golden as long as it has been maintained with genuine engine oil.
But if you see that their surface is black, especially if you can see a layer of black on the top of the cylinder head under the camshaft, then the engine of this car is also 80% of the use of fake oil, and I have dismantled the engine of a car in the previous show is very black.
The reason for the formation of these black sludge and carbon deposits is very simple, because the cylinder head needs to be responsible for the operation of the exhaust air temperature, so the temperature is very high, and the fake oil does not have any high temperature resistance.
Therefore, the fake oil used to lubricate the camshaft above the cylinder head will quickly form a sediment at high temperatures, which is the so-called oil sludge.
As long as one or two maintenance cycles with fake oil, the sludge basically deposited on the cylinder head and camshaft is visible to the naked eye, and with a few more uses, the reverse side of the cover of the oil filling port can also see the sludge.
What should I do with a car that has already used fake oil?
Many people buy a second-hand car or a novice owner for the first time to encounter this kind of thing, will be 4S shop or repair shop recommended to dismantle the engine to repair, the price is basically around 7000 ~ 10000 yuan, the key is that the effect after cleaning is not necessarily good!
So my personal advice is that as long as the engine can still run normally, you can try to replace the genuine oil every 1000 kilometers, the oil filter. Because of the genuine oil, it has the cleaning effect of sludge and carbon deposits, and the newer the oil, the higher the grade of the base oil, the stronger the role of cleaning the sludge.
In theory, as long as the oil change interval is shortened, the genuine oil can gradually clean the sludge inside the engine, and then the new oil filter element can help filter the sludge. So even if there is more sludge in the engine, as long as the engine can still operate normally, it can be saved, and it will not cause additional damage to the engine, and it will not delay the use of the car.
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