Questions and Answers
442 Overheats
Q. I have a problem with an Olds 442 5 speed. It's overheating only when it's stopped, it will not overheat while driving. I have changed the thermostat, water pump, radiator, checked timing and points and still overheats. The heads were taken off to see if the head gaskets were broken but they were okay. Also they checked the heads and they were fine also. Going crazy here.
Thanks
A. You didn't mention what year the car is, but I'll bet that it has a fan clutch and if it does, that's the cause of the overheating when it's standing still. The fan clutch has a temp sensor built into it and when the incoming air temp reaches a certain point, it engages and starts to pull more air through the radiator. The reason it doesn't over heat while you are driving is because there is enough air flow to cool the radiator.
You can tell if it is engaging by the sound. With the engine running, listen to the fan. When you first start it there will be little or no fan noise. As the engine warms up and the fan engages, you will hear a roaring sound from the fan as it starts to pull air. if you don't hear the roar and the engine starts to over heat, then you have a bad fan clutch and it needs to be replaced.
