12-26-07, 07:08 PM
I have a 95 Aurora that I bought about 3 months ago. When I got it the radiator had a small leak so I replaced it and flushed the system. The car runs a little warmer than it should. Driving around town and on rural backroads the car runs around 220. The highest it ever got was 229-230 according to my scan tool, that was sitting in traffic. On the highway at 70+ mph the car runs at 210-212. There are no leaks anywhere and the level is perfect. I checked the water pump belt and the tension is good. The system builds pressure and the hoses get hard like they should. Both fans work. I put in a new thermostat which changed nothing. I also made sure the purge lines were clear (aurora has two). Just for the heck of it I drilled two small holes in the old thermostat and the car ran at 183-190 on the scanner but naturally it took longer to warm up. The car would still get up to 220 if it sat long enough but that is normal. I also noticed that the lower radiator hose never really got hot, just warm. This lead me to believe that the coolant temp sensor was bad so I changed that too but it made no difference. So now I'm thinking it's the water pump. Maybe the impeller is corroded? I think it's the original with 119k on it. Any other ideas? I am fairly confident that its not a head gasket. No bubbles in the tank, no coolant loss, no sudden spikes in temp. The faster I go the cooler the car will run, which seems to be the opposite of a northstar with a bad hg. Also, if I floor the car the temperature will go down then slowly rise back up. Anybody have any ideas?