Re: Case of My E90 (320i) Disappearing Oil - 1 liter every 2000++km!!
Should not rush into changing valves just because someone else describe
same symptom as yours
Better to get ws to trouble shoot than to self-prescribe the fix
Most likely reasons how oil consumption varies:
1.Even when new, some engines will consume more oil than others.
In passenger cars, an oil use of 0.1-0.3% of the fuel consumption is seen as normal.
Even within the same series of engines, variations are present and about 20% of
the engines have a higher or lower oil consumption than average.
2.A long list of mechanical problems may lead to oil being used up,
such as wear and damage of seals and gasket, the bearings, cylinders,
ring grooves, connecting rods, etc.
3.Driving style has a huge impact on oil consumption.
Frequent acceleration and driving at high RPM will inevitably
increase both oil and fuel consumption.
4.Failure to respect the oil drain interval will lead to oil being used up faster.
Dirty oil will block the thin oil passages and some oil will remain trapped there,
instead of flowing back to the sump.
5.Inappropriate viscosity grade: too thin oils with lower than recommended
viscosity will tend to enter the combustion chamber easier and get burnt
together with the fuel.
6.Similar to a lower-than needed oil viscosity, too high engine temperature
will also result in thinner oil and increased consumption due to burning.
