I have a 1989 Cultlass Calais 2.5 with 83k original miles. I bought the car in Feb. from an old man's daughter after he died. I have had no problems until recently. Saturday I had the oil changed and the guy said I really needed to get my radiator flushed and the water was a nasty brown color. I had planned to have that done on Tuesday anyways so I waited. I took a 3 hour trip (each way) on Monday and it was about 95 degrees that day. I drove all the way with the AC on and had no problems. On the way back, after 2 hours I stopped for food. There were no lights on the instrument panel on to let me know that there was a problem. As soon as I parked and turned the car off, a huge amount of the dirty water came gushing out. OVERHEATED. I waited until thecar cooled off and filled the radiator full of water and put on a new radiator cap (there was a hole in the old one) and drove the rest of the way home with no problems. I drove 55 MPH, no AC, and it was considerably cooler. Then, I got a new thermostat installed and got the radiator flushed and filled. Today, I am driving to work, it's hot, I have the AC on and after about 10 minutes of driving, I'm stilling at a red light and the idiot light comes on. I immediately turn the AC off and turn the heater on and the idiot light instantly goes off. I thought maybe it could be the fan but the fan is working. It does NOT (and has never since I have had the car) stay on constantly..just when it needs to. I'm thinking it might be the waterpump. But I have been dribing the car a week since the first overheat...would I be able to drive for a week with a bad waterpump??? What else could be the problem? I just feel that even if it's hot, I should be able to have the AC on and NOT overheat. Please help!! Thank you in advance.
Amy