Water Pump Problems??
So your water pump is bad.. My best advice for you who are attempting a water pump on the 2.5 liter engine is get yourself the haynes manual. Also make sure to do this in a place where you can do some hardcore working on your vehicle!
Ok lets say you have all that done. Now it is time to fill up the cooling system. Recently, I did this. I replaced the water pump as well as the thermostat with OEM parts. no biggie. The problem that I ran into was AIR BUBBLES. I am not sure if the 2.5 engine didn't come with a good venting system or what. But this is the first time that I have ever had a problem like this. No matter how many times I filled it up, it would keep overflowing, and overheating.. Not to worry, you did the job right, but those air bubbles need to work themselves out. If you have air trapped in the cooling system just fill it up. Put all the caps back on, then let it run for a couple of minutes. Shut it off, and take off caps, CAREFULLY. Let sit for up to a couple of hours to allow the bubbles to work themselves up to the vent. Just keep repeating. I had to do this about three times before I had a good and air free cooling system.
Hope this helps someone..