Reader QuestionDear Austin
I am from Muscat Oman where summers are really hot. I have a problem of overheating in my 1995 Ford Mercury Mystique.
The temperature stays just below the middle mark while running and after driving for a bit when I need to stop at a signal or a turn I can hear the ac fan switch on however if I have to go slow in nose to nose traffic the temp rises and I have to switch off the ac but the temp does not come down. Aditionally if I have a straight drive for around 15 miles without any stops and have to return back home then when I reach home and switch off the car the water in the reservoir starts overflowing.
I have got my mechanic to clean the radiator and he says the water pump too seems to be working, his suggestion now is to put a swithc so that both fans work continuously and if this does not work the engine gasket will have to be changed as that is why the water is backing/boiling up into the reservoir.
I do not have any problem if I drive around 10 miles with the ac on minimum.
Will appreciate your opinion on what step to take
First, make sure there is plenty of coolant inside the radiator itself, not just in the overflow bottle, but open the radiator and look inside….with the engine cold of course.
Second, make sure the electric cooling fan is coming on when you have the a/c on. You might have two electric fans out by the radiator…or maybe just one. This electric fan should cycle on and off as the temperature gets hot, but it should also come on when the a/c is on.
If the fans are working, I would test the radiator to see if there is a restriction there. With the engine HOT, carefully run your hand on the top center portion of the radiator moving down towards the bottom of the radiator. There should not be a huge temperature variation between the top and the bottom of the radiator. If there is, there could be a restriction in the radiator, and a new radiator would be needed
Austin C. Davis