Questions and Answers
Dodge Intrepid Keeps Overheating
Q. Vince, My name is Rich, I have 1996 Dodge Intrepid with 118,000 miles on it. The car has started to overheat. The first time it happened was in the winter. I took it to a repair shop and they said they could not find any leaks. They did tell me I had oil in the Spark Plug chambers and the antifreeze is going into the oil. There is no water/antifreeze in the oil.
I did not have any problems for the rest of the winter.
Last week the car overheated again and it is continuously overheating now. I have replaced the thermostat and that did not resolve the issue. The car does not over heat while driving at highway speeds but it when you slow down to in-town driving it starts to overheat. Do you have any suggestions?
A. It sounds like the radiator cooling fans are not coming on. At highway speeds there is enough air flow through the radiator to keep the engine cool. But when you slow down, like city driving, there is not enough incoming air to do the job.
Run power to the tan and yellow wires at the fan motor connector. If the fan(s) come on, then we know the fans work. If not, then check the black ground wire. If the ground is good, replace the fan(s).
The Powertrain Control Module controls when the fan comes on and off. It uses the engine coolant temperature sensor to measure coolant temperature and turn the fans on. Since neither the high low speed fan or the high speed fan comes on, it's a safe assumption the low and high speed fan relays are good since it is not likely they both went bad at the same time. So this leaves the coolant temperature sensor, the PCM or the wiring as the problem.
A scan tool will be needed to accurately test these components.