General information about the lubrication system (VW Passat B3)

Despite all the efforts aimed at further improvement and increase in service life, operational safety and economy of VW Passat vehicles through design and production-technical measures, regular lubrication and maintenance of the vehicle in accordance with the system developed by the company remains necessary.

Operating conditions of motor oil

Depending on the operating conditions, completely different requirements are imposed on motor oils. At the same time, it is quite difficult to accurately determine the effect of different operating conditions on lubrication. In engines that operate for a long time at high crankshaft speed or at full load, the oil temperature reaches high values. Under the influence of high temperatures and atmospheric oxygen, the oil begins to oxidize. Oxidation products thicken the oil and can be deposited as varnish films on the upper parts of the pistons, in the grooves under the piston rings and on the valve stems. The latter can lead to coking of the valve plates.

Dilution of oil in gasoline engines

If the cylinders receive an over-rich fuel-air mixture, if the engine rarely or never operates at maximum power, if the engine temperature is below operating temperature (city driving), then incomplete combustion occurs as a result. Soot, oil carbon and other products, unburned fuel itself and moisture condensation lead to the formation of sludge, acids and asphalt. Unburned fuel settles on the cylinder walls and flows into the crankcase, while the oil film is washed off the surface of the cylinders and pistons. The result is a decrease in the lubrication of the working surfaces of the pistons and cylinders and dilution of the oil, which worsens the lubricating ability of the oil depending on the fuel content in it.



If the dilution is too strong, it is necessary, if possible, to carry out an early oil change. Since during extreme trips (when the engine is hot) since some of the gasoline evaporates from the oil, it is necessary to monitor the condition of the oil more often, especially in winter (more cold starts - higher proportion of gasoline in the oil).

Viscosity of motor oil

Oil viscosity refers to its fluidity. Under the influence of temperature, oil tends to change its fluidity. When heat is supplied, oil becomes liquid. As a result, the load-bearing capacity and strength of the oil film decrease. In the cold, oil becomes thick and less fluid, and its viscosity and internal friction increase. This property requires the use of oil with a viscosity that changes as little as possible with temperature changes. When the engine is cold, the oil should still be so liquid that it does not excessively hinder the operation of the starter and, after starting the engine, reaches all rubbing surfaces as quickly as possible.

The original text is available on the portal (vwmanual.ru)

The fluidity or viscosity of oil is equivalent to its internal friction and is designated according to the SAE classification (Society of Automotive Engineers), for example, SAE 30, SAE 10, etc. The higher the number in the oil designation, the more viscous it is. However, the viscosity of the oil does not allow us to draw a conclusion about its lubricating properties.

All-season oil

All-season oils are provided for VW PASSAT engines. This has the advantage that the oil does not have to be changed with the onset of a new season (summer/winter). All-season oils are produced on the basis of low-viscosity seasonal oil (for example, 15 W). Thanks to the so-called thickener, the oil is stabilized in a hot state, so that the required lubricating capacity is achieved in each operating mode. If an all-season oil is used, modern oils should be used, which have a wide viscosity range (for example, 15W-40,15W-50). The "W" designation in the SAE classification indicates the suitability of the oil for use in winter.

Low friction oil

Low friction oils are all-season oils that, among other additives, contain friction modifier additives, due to which friction in engine components is reduced and fuel savings of up to two percent can be achieved. Low friction oils have low viscosity (for example, 10W-30). The base oil for them is synthetic oil. When buying low-friction oil, you need to pay attention to the fact that it is approved for use by VW/AUDI.

Applications/Viscosity Classes

A - Heavy-duty and low-friction motor oils. In accordance with VW 500 00 and 505 00 standards.
B - all-season oils. According to VW standard 501 01, 5 W oils are only for petrol engines.
C - seasonal oils.

Since the application areas of adjacent SAE classes overlap, short-term fluctuations in ambient temperature can be ignored. It is permissible to mix oils of different viscosity classes with each other if the oil level needs to be topped up and the ambient temperature no longer corresponds to the viscosity class of the oil in the engine.

Additives, no matter what kind, must not be mixed with either fuel or lubricating oil.

Motor oil specification

For modern engines, only heavy-duty motor oils HD-Oil are permitted for use in principle (Heavy-Duty-Oil). These oils contain chemical additives that significantly improve their lubricating properties. The additives improve corrosion protection, have antioxidant properties, prevent the formation of sludge in the engine crankcase, improve the viscosity, cleaning and dissolving properties of the oil. Cleaning and dissolving additives not only reduce the formation of deposits in the engine, but also have the ability to dissolve deposits and hold them and other oil contaminants in a finely dispersed form in a suspended state, which allows all contaminants to be drained along with the oil when changing it.

, The quality of motor oil is designated by the American API system (American Petroleum Institute). The oil characteristic is given, depending on the circumstances, by two letters. The first letter indicates the area of application: S (Service) — the oil is used in gasoline engines; WITH (Commercial) — oil is used in diesel engines. The second letter indicates the quality in alphabetical order. According to the API specification, the highest quality is SG oil for gasoline engines and CD oil for diesel engines. Note: Motor oils with the CD designation, which are designated by the oil manufacturer as oils for diesel engines, are not suitable for gasoline engines. However, there are oils that are suitable for both gasoline and diesel engines. In this case, both specifications are indicated on the oil packaging (eg SF/CD).

VW has set its own oil standards. Only oils that meet these standards should be used. The VW standard is indicated on the oil packaging. If in doubt, you can ask the seller about approved oils.

All-season oils that meet the VW 501 01 standard are required for gasoline engines. Low-friction oils that meet the VW 500 00 standard can also be used. All-season oils (VW 501 01) are generally inexpensive. If oil of this specification is not available, API-SF or SG specification oil can be used temporarily.

Specification of oil for naturally aspirated diesel engines (65/68 hp): VW 501 01, VW 505 00, API-CD or heavy-duty engine oils that simultaneously meet VW 500 00 and 505 00 standards. If an oil that meets the specified VW standards is not available, an API-CF multigrade oil can be used to top up the level.

Oil consumption

In relation to an internal combustion engine, oil consumption is understood as the amount of oil that is consumed as a result of the combustion process. In no case should oil consumption be equated with oil loss that occurs due to leaks in the oil pan, cylinder head cover, etc.

Normal oil consumption occurs due to its combustion in the cylinder, as well as due to the removal of combustion products and wear particles. In addition, the oil ages under the influence of high temperatures and pressures to which it is constantly exposed in the engine.

In addition, oil consumption is affected by external operating conditions, driving mode, and manufacturing tolerances. The highest oil consumption should not exceed 1.5 l/1000 km.

Of course, the oil level should be topped up if it has dropped to the "Nachfull" mark (then a maximum of 1 l is required for refilling).