No, all 2.5Ghz G5 PowerMac's are Liquid Cooled, AFAIK. There was a dual CPU model and a later dual core plus dual CPU's, known as the quad core G5 PowerMac.

I would wager that most liquid cooled G5 PowerMac's have leaks that look just like the picture posted in the link in this thread. I also rebuilt my dual 2.7GHz G5 PowerMac's liquid cooling system seals to insure that it would not leak again and cleaned all of the corrosion from the heatsink.

I also strongly suggest that anyone who has purchased a liquid cooled G5 do the same.