Oil Level Alert on Mercedes-Benz
This bulletin applies to all Mercedes-Benz gasoline engine vehicles equipped with an oil level/pressure sensor, with no mechanical dipstick. On engines equipped with an oil level sensor, the instrument panel may indicate that the engine contains too much oil.
If the vehicle is mainly driven in the city or used for frequent short trips where engine operating temperature is not reached, with frequent cold starts and lots of short trips, fuel can enter the engine oil in non-combusted condition.
Fuel outgassing through crankcase ventilation is only possible once operating temperature is reached. If normal operating temperature is not reached, the ingressed fuel collects in the engine oil which in turn leads to an increase in monitored oil level. This obviously can reduce oil viscosity which can damage the engine.
On vehicles that are primarily used for short trips, the engine oil level should be checked on a frequent basis.
If required, drain the fuel tank, and replace the engine oil and filter.