I Just bought a 99' 323i two weeks ago and I love the car, but out of nowhere the car overheated. I thought it might be the water pump or the thermostat so I replaced them both. When I took the water pump out it was shredded, the plastic impellers didn't make it. I figured that would be the cause of the overheat. I also replaced the upper and lower hoses, the auxiliary fan, and the coolant temp sensor. Oh I also drained the old coolant out and put new coolant in and bled the system as well. It's still doing the same thing as before only it doesn't overheat quite as fast. It doesn't blow out any hot air when I have the heat on full blast and if i put the A/C on cold it only blows out the driver's side and then the car overheats real fast. I don't know where to look next and was hoping someone could point me in the right direction before I'm forced to take it to the dealer and get back doored from them. Any help would be greatly appreciated. Thanks again.