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oh sweet, is it a big job? cost much if a mechanic does it? Do I have to pull the whole engine out, etc...?That's the water pump underneath that wheel could be the gasket leaking but if it were my car I'd go buy a new water pump (new gasket should come with it) and be done
It's most likely the water pump seal failing and it's leaking from the small hole under the pump. If so, change water pump pronto.
It's not a big job but it can be a bit of a pain, best to ring around a few mechanics and get some quotes.
I would suggest a new thermostat at the same time if it hasn't already been changed recently.