General provisions
The engine oil must meet specification VW501 01. There are also no restrictions when using multigrade oil of specification VW 500 00. However, light oils of these specifications are not allowed for use in diesel engines.
For gasoline engines, in the absence of oil of the above specifications, all-weather or single-season oil of API SF or API SG specification can be used. As for diesel engines, if necessary, it is allowed to fill with all-season oil of API CD specification or single-season oil of the same specification.
Mineral all-weather oil specification VW505 00 can be used without restrictions for AUDI 80 vehicles with a diesel engine.
The main requirement for engine oil is its viscosity. It should not be too viscous, otherwise the starter will have difficulty starting the engine, but it should not be too fluid either. In this case, at high engine temperatures, «gap» oil film.
American Society of Automotive Engineers (Society of Automotive Engineers — SAE) divided motor oils into classes depending on viscosity. Thus, palitramasel includes easy-flowing winter oils SAE 5 W, 10 W, 15 W, intermediate SAE 20W / 20 and viscous summer oils SAE 30, 40 and 50 (see illustration 19.0).
The cheapest is one-season oil. Subject to the requirements regarding viscosity and with timely seasonal changes, AUDI does not prohibit the use of such an oil. Currently, one-season oil has practically disappeared from the market. It was replaced by multigrade oil, which has a viscosity improver in its composition, the molecules of which swell when heated and shrink to their original state when cooled. Thus, this oil easily adapts to temperature changes. Oil SAE 15W-50 at -15°C corresponds to a viscosity class of 15W, and at a temperature of 100°C - class 50.
Some problems arise with multigrade mineral oil. In this case, over time «cutting» chains of molecules and the oil loses its universal properties. For this reason, SAE 10W-30 and 10W-40 oils are excluded from the list approved for use in AUDI vehicles.
Attention! AUDI expressly prohibits the use of any additives in engine oil. Their use is considered a violation of the vehicle operating instructions and, accordingly, excludes the validity of the corresponding warranties.
Oil circulation
The oil pump sucks engine oil from the oil pan through the intake pipe and pumps it into the oil filter on the oil line (see illustration 19.0a). From the filter, engine oil through the injection channels in the cylinder block enters the lubricated parts of the crankshaft, intermediate shaft, cylinder head and camshaft. The oil then flows back through the holes into the oil pan and is re-taken from there by the oil pump.
The turbocharger parts are lubricated with engine oil supplied through a separate oil pipeline.
There is a relief valve on the oil pump. It is designed to supply engine oil to the main oil pipeline in case of clogging of the replaceable filter element. In this case, the bypass valve opens and oil is supplied bypassing the oil filter.
An oil pressure relief valve is located on the pressure side of the oil pump. This valve opens when the oil pressure is too high and some of the oil may drain back into the oil pan.
In one minute, the oil pump pumps about 30-35 liters of oil at full engine load. The drive of the oil pump of four-cylinder gasoline and diesel engines is carried out from the intermediate shaft. The oil pump of the five- and six-cylinder engines is driven by the crankshaft.
AUDI installs two types of oil pumps on its vehicles. Four-cylinder gasoline and diesel engines are equipped with a gear oil pump, in which engine oil is sucked into chamber 1, and from it is supplied to pressure chamber 2, from which it is directed under pressure to the oil filter and then to the oil pipeline (see illustration 19.0b).
Five- and six-cylinder engines are equipped with a rotary-type Eaton oil pump with pressure reducing valve (see illustration 19.0v).
Oil temperature is essential to engine performance. The installation of an engine oil temperature gauge is an optional feature of the vehicle. AUDI considers an engine oil temperature in the oil pan of 145°C to be the maximum allowable.
Too low engine oil temperature adversely affects the condition of the engine. For this reason, it is recommended not to exceed 3500 rpm after starting a cold engine. until the oil temperature exceeds 60°C. For gasoline engines, there is an unwritten rule that engine oil takes twice as long to warm up to operating temperature as coolant. With regard to diesel engines, in winter the oil reaches a temperature of 60°C after about 10 minutes after starting the engine, and in summer after about 6 minutes.
Diesel engines are equipped with an oil cooler that cools the engine oil. On TD engines, the oil cooler is located to the left of the engine. The use of an oil cooler also has a negative meaning, the meaning of which is that in such cases the oil will slowly reach the operating temperature. To avoid this situation, an oil temperature regulator is installed on the oil filter flange. This regulator allows engine oil to pass through the oil cooler only at temperatures above 110°C. At lower temperatures, oil access to the radiator is closed. This means that the engine oil temperature regulator itself must heat up to 110°C, which will allow engine oil to enter the radiator (see illustration 19.0g).
On AUDI 80 TDI cars, an oil cooler is installed, which works on a different principle. This oil cooler is constantly «washed by» coolant. When starting a cold engine, the engine oil is heated by the heated coolant.
Visitor comments