If this is a garage then clearly it's a very ameturish setup, even an idiot knows to fill with anti freeze remember it's not just there for to prevent freezing it also has a anti corrosion inhibitor. If it was me personally I would wrap the engine with a blanket etc and let it thaw naturally as one extreme of temperature to another is never a good thing, I certainly would not start or drive.

The pump runs off the aux belt the same as it does on most cars not the timing belt.


Martin