QuestionThis was the question I asked earlier and I was hoping I could get a different opinion. (I am going down the highway on a trip and the temp gauge is just rising but the engine has plenty of coolant. I was wondering how to replace the thermostat in a 74 plymouth scamp) I dont know if the thermostat is the problem but it doesnt raise in temp most times I ride around town.
AnswerI don't recall this question - I think it must have gone to someone else. The thermostat is not too likely a culprit here - because if it were stuck shut, you would have overheating very quickly even on a short drive.
More likely, the lower radiator hose is collapsing, if your symptom is that it only overheats at high speeds. Since you didn't tell me what engine is in the car, and what maintenance has been done on the cooling system, I'd be shooting in the dark if I made any other suggestions here. If you want to try to fix it yourself, first step is to make sure the lower radiator hose has the internal spring in it (many modern folks don't realize what it is for, and leave it out), and if it doesn't, replace the hose with a new one with the internal spring, so it cannot collapse at high speeds. (The water pump actually pulls a vacuum on that hose as high speeds).
If that doesn't cure your problem, take the car to a radiator shop and have them check out the whole cooling system. There are many, many possible causes - most of which are expensive to fix!
Dick
