It could be by the way it is running, but the check engine light would come on indicating a problem.
The light isn't on but the oil on my dipstick is getting higher up
Then you have a blown head gasket.
By chance do you live in Washington State? I knew a John Roberts out there...
If the oil smells of gasoline and the level is increasing a fuel injector that is leaking is the likely cause. This will not cause the oil in the engine to look any different. A blown head gasket that is leaking coolant into the oil will make the oil look much like chocolate milk.
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