Engine Cooling problem
1997 Chevy Lumina 6 cyl Front Wheel Drive Automatic 195000 miles
When driving on the highway, the temperature is normal but when I exit and slow down, the car overheats. I pulled over and noticed antifreeze gushing from under the hood so I popped the trunk. It was coming from the reserve tank. I did notice earlier that the reserve was too full.(I just bought this car, first highway trip) Now, the excess coolant is out, it is at the right levels. The car cooled and I got back on the highway to continue, got caught in traffic and had to slow down, the car overheated again. I pulled off and heard a strange sound, once again popped the hood and found the antifreeze in the reserve tank boiling. It wasn't leaking anywhere, just boiling in the tank like a pressure cooker. Where should I start here to find the problem? My auto knowledge is pitiful but I can't afford a mechanic. Anything I can check or replace myself that doesn't require more than a Chilton manual and basic tools?
EDIT: just ran the car until it overheated. When I initially started it, the radiator fans were on. After about 5 minutes, they shut off and didn't turn back on again. I waited about 10 minutes, they never came back on and the car overheated. I turned it off, restarted it to see if the fans would turn back on, they didn't. Why would they work upon initial startup and quit when the car got hot? What should I check here?
Friday, June 27th, 2008 AT 11:18 AM