I just switched out the coolant temperature sensor on my car. The old one had worn out and sprung a leak somehow. And after driving the car for about a minute the temp gauge rose to about halfway. I know this is normal for most cars, but this is something that the car(gauge) had never done before. I know the other sensor might have been failing so it might not have been accurate, but it never did this in the 4 years that I have been driving the car. I am wondering if there might be some sort of air block in the cooling system. Maybe air got in while I was replacing the sensor. If it is an air block how do I get rid of it?
As long as your overflow bottle is at proper level any air may work it's way out. And the new sensor may read higher.
October, 31, 2012 AT 5:07 AM
You're looking at this backward. It was not working correctly before but it is now. Why do you want to go back to reading inaccurately? If the radiator fan is working like normal and there are no signs of overheating, the little air that might have entered will burp into the reservoir and all will be fine.
October, 31, 2012 AT 5:12 AM
I guess I might be over-reacting a bit, I'd just never seen the temp gauge increase that fast. Usually for the whole time I've used the car I could drive about 5 minutes on the street before the gauge got to the middle, and drive on the highway for over half an hour before it got there. Just got me nervous that it was midway before driving a quarter mile.
October, 31, 2012 AT 10:37 AM
That does seem too soon. It shouldn't be reading a normal temperature in less than a mile or two. You might want to find a scanner you can borrow to view live data on a test drive. That will show the actual coolant temperature the Engine Computer is seeing from its coolant temperature sensor.
Someone else recently posted a reply that there are different gauge sensors for different engine sizes or years that bolt in the same but have different resistance values. These sensors don't fail very often, other than Ford's sensors for the Engine Computer, so the wrong sensor would make sense. You can also compare the resistance of the old and new sensors but that has to be done when they're at the same temperature.