2004 Chevrolet Impala Thermostat Reads Car Overheating Fans Constantly Running

you need a shop with a scan tool to look at the actual temp being sent to the pcm. driving it may damage the head gaskets, if they arnt already damaged.

get it checked asap.

Roy

Hello. First, I would check the coolant level to make sure you didn't lose any coolant. Another problem could have appeared after you put a new cap on the bottle and it pressurized the system. One thing to look for is the 3100, 3400, and 3800 have problems with their intake gasket leaking. This is very common. It usually leaks on the driver's side under the intake and is very noticeable. If this is the case, you have to change the intake gasket. If not, it is another issue. Next, plug in an O B D 2 scanner to see if there are any codes. The scanner will tell you if it overheated by setting a code. It will also tell you the actual temperature that the car is running (so you can tell if the gauge has failed), and can help you determine if you need to check the head gasket for leakage. Finally, always remember to check fuses in case one is blown.