In very round figures, about $400 parts and labor. Put your own zip code in the estimator below for a closer figure. The water pump is driven by the timing belt, so you should add another $100 - $200 for the pump. Replacing it is optional, but you are running the risks of having the pump start leaking and having to spend another $400 labor to replace it or of it seizing and destroying your engine by ruining the timing belt.
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