On my 1994 F150 the dash gauge that shows the temperature has always bothered me when I drive down the road. One second when i look at it, it is reading around N and O then it will jump up to around the R and M range and stay there for a bit and fluctuate back and forth. I have gotten a new radiator, temp sensor, and new heater plug installed recently and it still has had this problem. I don't know if there is anything that I can do to remedy this issue or not but it is really annoying to be driving down the road and not knowing if the engine is running fine or if it is over heating. Below is a picture of the Temp gauge so you know what I am talking about when I list off the letters.



Thanks in advance for your feedback

 

I have a 95 f150 with a 302 and mine used to do the same thing until I found out there was two sensors for the water temp. One on the thermostat housing which tells the pcm what temp the motor is running at and the other one is on the intake manifold to the right side of the distributor. Its kinda down in there, you have to look for it. It has a single wire that just pulls off.
The replacement of the one by the distributor fixed my problem.

 

Do you know what that part is called. I dont thing that the guy that did the work on my truck replaced that one when he replaced the radiator. how dificult is it to replace, like can I do it in my driveway? Can you include what it should look like so i dont buy the wrong thing?

Thank you so much for the feedback!!!!

 

I think it is called the temp sender.

 

This looks like the one I put in.You may be able to find it cheaper if you do a search.

http://www.ebay.com/itm/BRAND-NEW-OE...tVToDM&vxp=mtr


It is very easy to replace, just make sure the engine is cold or you will get a face full of hot coolant. Just pull the wire off, put a deep well socket on the sensor and unscrew it, put the new one in, tighten and put wire back on. Simple
P.S. You may lose a small amount of coolant unless you work fast.

 

The one in that picture is mislabeled ( it is the temp sender) - it is the one you want to replace though. It runs your dash gauge. It is located on the driver's side of the intake manifold between the 1st and 2nd bolts.
The one that sends a signal to the PCM is called a temp sensor - it's located above the thermostat housing on the standpipe that comes up from the intake. That's not the one you want to replace.

 

Is there a way to test if the temp sensor (in thermostats housing) is functioning properly?

 

Change the thermostat.

 

Probably, but if you really suspect it they're not particularly expensive and not hard to change. If you're going to bother, buy Motorcraft.