3.0 BiTDI V6 Plus SUV
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£22,995
- Year/Month: 2017/0
- Stock ID: T118271
- Transmission: Automatic
- CC: 3000
- Mileage: 107500
- Fuel Type: Diesel
- 234 Views
The EGR valve is a mechanism designed to reduce polluting emissions, both in diesel engines and in gasoline. So, a buyer of used Audi q5 TDI for sale should know about that. Normally the EGR valve opens or closes at low and medium speed. As you have already imagined, if the air introduced into the combustion chamber has less oxygen, only the fresh gases, which do have oxygen to burn, react when the explosion occurs in the cylinder.Â
Side Effects
Therefore, less heat will be generated, which is the desired effect to reduce the formation of nitrogen oxides. When maximum power is demanded, that is, when it accelerates to the bottom, the EGR valve remains closed, does not act; because in these circumstances it is necessary to supply air with as much oxygen as possible, that is, fresh air. So far, the theory. But what happens in practice? Does the EGR valve have side effects for the engine? Indeed, as you may have thought, if we put less fresh air and the combustion is less powerful, so to speak, in a certain way the EGR valve limits the performance. True. In fact, something similar to what happens with particle filters, which need a series of additional injections of fuel to raise the temperature and regenerate the filter by burning the accumulated ashes when it is full.
Intake And ExhaustÂ
The intake valve fulfills the function of connecting the intake manifold with the cylinder depending on the distribution time, they are generally made of single metal steel with chromium and silicon alloy that allows a good resistance to heat and work. It is usually tempered the metal of some areas to reduce wear such as the seat, stem and head. The exhaust valve is in constant contact with the exhaust gases that are at very high temperatures, so they must have a stronger structure than the intake. The heat accumulated in the valve is transferred through its seat.Â
Saucer And Shank
Besides, the valve, due to its singular function, must be constructed of different materials, its saucer and shank are generally constructed of steel with chromium and manganese alloy that has the great quality of resisting oxidation and high temperatures. In the high section of the shank, they are usually constructed of chromium-silicon. For the thermal conductivity, saucers and hollow rods are made that are filled with sodium, which has the function of transferring the rapid heat to the refrigeration zone, reducing the temperature in the dish. Before pay the used Audi q5 TDI price, it will be better to know that, the intake valve allows the air and fuel mixture to enter, in the case of engines with a carburetor, or the air only in a small number of injection engines. On the other hand, the exhaust valve allows all combustion gases to escape. The intake valve is larger diameter to favor the easy entry of elements for combustion. On the other hand, the exhaust is smaller diameter so that the gases are forced by the pressure exerted by the piston.