So I've read in a thread that the water pump will begin to leak when it goes bad. Can you guys confirm this?

Over the past 3 weeks or so, I've smelt coolant but not been able to find any leaks.

The fans started to act up about 3 days ago. They would sound like they were on when they normally aren't.

Then today the car began to overheat. When I put on the heater, it blew cold air. I've purged air before, so I don't think it's air trapped inside. So I'm thinking the water pump is bad.

How involved is it to replace it? I'm pretty mechanically inclined, does it involved removing the front timing chain cover? 03 G35 btw...

 

Yes you have to remove the timing cover and the chain to get the water pump out.