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Oil Filter, Replace (X 14 XE, Z 14 XE, X 16 XEL, Z 16 XE, Z 16 YNG, Z 18 XE and Z 18 XEL as of MY 2002) > < Oil Pressure, Check

Astra G

Oil Consumption, Measure

General

The term "oil consumption" of an internal combustion engine refers to the amount of oil which is used as a consequence of combustion. Oil consumption should under no circumstances be confused with oil loss caused by leaks in the oil pan, cylinder head cover, etc.

The task of the engine oil is to:

1. Separate surfaces that slide on one another with an oil film, i.e. prevent dry friction;
2. Conduct the heat produced by friction away;
3. Conduct combustion residue away.

These tasks require a certain oil consumption, in other words, the often-expressed hope that as the combustion engine continues to develop it will no longer require oil is totally unfounded. Oil consumption is, however, influenced by external operating conditions, driver behaviour and manufacturing tolerances. Make sure that the oil level is never below the "MIN" mark on the dipstick and never above the "MAX" mark.

As oil consumption is a technical necessity, indications that an engine is not consuming oil mean that it is reasonable to conclude that the oil is being diluted by particular operating conditions. Frequent cold starts, driving when over-cold, etc., lead to the oil returning to the oil pan conducting fuel particles and condensation, and thus becoming "diluted"; this can lead to the incorrect supposition that the engine is not consuming any oil at all.

Oil diluted in this fashion lacks lubricating power and may lead to engine damage if the specified oil change intervals are not observed. The main causes for oil dilution are driving in mainly urban traffic and frequent driving at insufficient engine rpm when the engine is cold.

The oil consumption first begins to stabilise after operating for a few thousand kilometres; therefore, measurements of the oil consumption only become realistic after about 7500 km/4000 miles. Before measuring the oil consumption, ensure that the engine is not losing oil due to leaks.

Note:   The oil dipstick can only be used for checking and not for measurement. The engine must always be switched off for at least 2 minutes before the oil level can be checked. If, after an oil change, the maximum engine oil filling does not match the maximum level mark on the dipstick, this can be attributed to manufacturing tolerances.

All information regarding the permissible engine oil consumption and filling quantities are included in the User's Manual.

Measuring Method

1. The checking procedure is carried out with the vehicle on a horizontal surface with the engine at operating temperature (engine oil temperature at least 80 °C/176 °F).
2. Drain engine oil immediately after switching off engine – draining time approx. 30 minutes (this value was determined experimentally).
3. The drained engine oil quantity is determined in a measuring container 1) and fresh oil is added up to the maximum engine oil filling quantity, minus the volume for the unchanged engine oil filter.
4. Using this amount of engine oil, the customer should drive at least 1000 km/625 miles without of course topping up the engine oil (the driver should keep to his normal routes and driving styles).
5. The procedure described above (points 1 to 2) is then repeated with exactly the same time for draining engine oil.
6. The quantity of engine oil "missing" from the measuring container is the engine oil consumption with respect to the distance travelled.
7. The oil consumption is calculated as follows:

filled oil quantity (I) – drained oil quantity (I)

x 1000 = oil consumption (I/1000 km)

distance actually driven (km)

1 ) Measuring container with min. 6 litres capacity and a graduated scale.
Related Literature Units
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Oil Filter, Replace (X 14 XE, Z 14 XE, X 16 XEL, Z 16 XE, Z 16 YNG, Z 18 XE and Z 18 XEL as of MY 2002) > < Oil Pressure, Check