First off I want to say Hi, this is my first time on the site. I am used to forums like this as I am a member of one for my Prelude and am glad I was able to find one for the Sonata. Some background, I am a Honda guy and this is my first Hyundai. I got it from my dad about a month ago and haven't had any problems up until recently. My first issue was I was sitting at a drive thru and I began to overheat. I was close enough to home that I was able to make it there and let it cool before I looked at it. It had turned out I was low on coolant so I added some and went from there. Just before that though I had replaced the upper radiator hose because it was collapsed and I replaced the radiator cap. The fluid levels looked ok. Well since this encounter it has happened a few more times, At first it only appeared to be at an idle with the ac on but last night was the first time it began to overheat while driving and I just barely made it home (only from a series of shutting the car off cooling down and making short runs). I added water again today as it was empty again and was noticing a strange noise. I can best describe it as a slurp kind of noise from the water pump area and my neighbor said the pump is probably bad. I have checked for leaks and have no visible leaks from lines or anything. If I am losing coolant it is while the car is running and in motion. The fans do come on and the thermostat has beem removed for the purpose of diagnostics (but it is good I boiled it and it has full range). Car has 136,000 miles on it and I honestly am not sure if the pump has ever been replaced. So my question is if this does sound like the pump how difficult is it to replace? Like I said I am a Honda guy and I have pulled the head off of my DOHC Prelude a couple times but it is only a 4 cylinder so this will be a new beast for me. I really don't have the money to have a shop do it which is why I am doing it myself. I also know that with the water pump I will be replacing the timing belt but is the tensioner important as well in these cars as they are hydraulic correct? I am just looking for some insight as to what I am getting in to. Any help and suggestions is appreciated.