The so-called "oil overflow" means that when refueling, after automatic jump of oiler, oiler is still raised at this time and continues to be filled into fuel tank with a small amount of oil. Gasoline vaporizes easily and expands more easily when heated, so buffer space should always be left for fuel tank, so actual fuel tank capacity is larger than capacity listed in manual. If gasoline is overfilled, buffer space originally used to prevent fuel tank from expanding will be too small, potentially causing problems.
We know that overfilling is primarily bad for coal tank. The charcoal tank system is mainly composed of a charcoal tank, a charcoal tank solenoid valve and related oil lines. The charcoal tank is used to absorb gasoline vapors. First, it can prevent evaporation of gasoline vapors and air pollution. Secondly, it can participate in combustion of this gasoline and reuse it to save energy. After starting car, solenoid valve of charcoal tank will be opened in time, and gasoline vapor absorbed in charcoal tank will enter cylinder with clean air under vacuum of intake pipe. to participate in combustion, and pressure will be released at same time, so part of carbon filter involved in combustion of gasoline is also part of ECU programming.
The carbon tank can be found in car's chassis
Overfilling gasoline will result in a lack of space for buffering, and expanding vapors of gasoline will easily drain into charcoal tank. The activated carbon in charcoal tank will absorb too much gasoline and cannot be drained and will gradually agglomerate. Aggravated that it is easy to affect service life, especially in hot weather, car is not easy to catch fire, mainly due to coal tank. A specific symptom is that car starts poorly in hot weather and returns to normal in cold weather, and in cold weather air resistance disappears and ignition returns to normal.
Besides affecting life of charcoal tank, what harm will frequent overfilling of fuel tank cause? This question is easy to answer. If you add too much oil, oil will spill out easily. Gasoline is highly flammable and may ignite on contact with an open flame. This poses a serious security risk. If weather is hot and in sun, whole car will smell like gasoline. In fact, if carbon filter fails, it will also cause a distinct smell of gasoline in car. In addition, too much fuel in fuel tank can cause negative pressure in fuel tank, inaccurate readings of fuel gauge, and can also have an additional effect on engine performance, in particular, manifested in fact that mixture is too rich, which is also possibility of damage. reservoir with coal. Conditioned reflex. We know that too rich a mixture will cause incomplete combustion and a large amount of carbon deposits, which will further damage oxygen sensor and three-way catalytic converter when it is ejected from exhaust pipe.
Oxygen carbon sensor
As a general rule, fill fuel tank as much as possible at one time to avoid trouble, but this is clearly not recommended. In normal refueling, it is enough to add oil to jump gun. Do not use other additional operations to add more oil, this will only bring harm, but will not bring any benefit.