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RolfAndreassen comments on Yet more "stupid" questions - Less Wrong Discussion
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If I understood the Wiki article correctly, the assumption needed to derive Liouville's theorem is time-translation invariance; but this is the same symmetry that gives us energy conservation through Noether's theorem. So, it is not clear to me that you can have one without the other.
Liouville's theorem follows from the continuity of transport of some conserved quantity. If this quantity is not energy, then you don't need time-translation invariance. For example, forced oscillations (with explicitly time-dependent force, like first pushing a child on a swing harder and harder and then letting the swing relax to a stop) still obey the theorem.