The fuel pump can put a lot of gas into the oil and still supply enough to run the engine. Is the oil very thin, with a strong smell of gasoline? About the only thing that can make the crankcase level rise that fast without turning the oil a milky brown color (coolant) would be the fuel pump leaking gas.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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