Engine oil sump

At the bottom of the engine.

The sump stores oil around a pickup; baffles and system layout manage oil during vehicle motion.

The reservoir below a recirculating fountain.

External leaks, impact damage or pickup problems can affect oil supply.

Fluids use vehicle-specific schedules. Seals, pumps and heat exchangers depend on age, condition and operating history.

Simple seals and filters can be accessible; an integrated pump, buried housing or overheating damage can make repairs more involved.

BMW combustion models; additional coolant circuits also appear in hybrids and electric BMWs.