If your vehicle is showing oil level on the dipstick is inexplicably rising, here are the most likely causes and the parts you'll need to fix each one.
The engine was simply overfilled with oil during a recent service, or oil was checked/added while the vehicle was parked on a steep incline.
On direct-injected engines, the internal seal of the high-pressure fuel pump can fail. This allows raw gasoline to leak directly into the camshaft area and drain into the oil pan, raising the level.
A fuel injector is stuck open and leaking fuel into the cylinder after the engine is shut off. This fuel washes past the piston rings and accumulates in the oil pan.
Frequent short trips prevent the engine from getting hot enough to burn off normal condensation and fuel blow-by. A clogged PCV valve traps these vapors in the crankcase, causing the fluid level to rise.
A failed head gasket allows engine coolant to leak into the oil passages. This raises the fluid level and usually turns the oil into a milky, frothy substance.
On certain engine designs (especially older V6 and V8 engines), a failing lower intake manifold gasket can allow coolant to pour directly into the engine valley and down into the oil pan.