Hello everyone, Ok some of you know I was tackling the job of changing out changing out my lower thermostat housing. I have completed the job. I bought the part from amazon it was the lower and upper thermostat housing with a thermostat already in it. I got it replaced. Took me about 7 hours total taking my time. However, I have everything back together flushed the system twice and now have replaced with coolant and distilled water. NOTE I did replace both temp sensors also. Now I drove it for about 30 min and them temp never gets above the bottom line of C. I dont know why. Its either a issue with the thermostat or the sensors. Has anyone else come across this issue before? I know the vehicle is not over heating but it should be half way between the C and H lines. Any help or ideas would be appreciated. Thanks

 

Did you go OEM or aftermarket? Was one sensor a "sender" (one wire or two)? Did you burp the system?

When I replaced the heads on my '95 Aerostar, I thought I would do a good thing and replace the temperature sender (the sensor for the gauge that has one wire) even though the old one hadn't failed. When I fired it up and let it run long enough to get warm, I nearly had a heart attack when I looked at the temperature gauge. The temperature was way over what I was used to seeing, but not in the overheat zone. I had replaced the temp sender with an aftermarket unit. I put the Ford sender back in and the temperature went back to where it always had been.

I haven't had a thermostat be bad right out of the box or cause a noticeable change on the gauge. And, I'm sure the sender I used was "within spec", but it was different enough to cause the gauge to read higher than what I was used to seeing. If the sender can be off in a manner to cause the gauge to read high, I'm willing to bet a different one could be off such that the gauge reads low, especially if you go aftermarket.

You might be able to find a resistance vs. temperature chart online and compare that to what you're seeing. That might help, but you'd also need an independent means of measuring temperature.

 

Yes they are aftermarket, there are two sensors in there. They were both two wire and seemed to plug in just fine. One of the sensors I could not get out of the old housing because the nut in the housing that held it in stripped and would just spin when I tried to take it out. I just really don't want to have to dig all the way back in there to replace with Ford sensors. I do understand what you are saying though. Thanks for the reply

 

The sensor doesnt unscrew. It is held in with a wire clip. The sensor has an oring.
Do you get any heat from the heater? Are the upper and lower radiator hoses hot? If yes to both, try swaping with the old sensor.

 

Mine has the type that screw in they are threaded. Yes the upper hose is hot to the touch. I was squeezing it to make sure there were no air bubbles in it. I just found out that I now have a small radiator leak from the plastic tank. Yay if its not one thing its another. I cant put the ones that were in there back in because I can't get it out of the old housing. I may end up just buying new ones from the dealer OEM ones. Its just a B!tch to get access too them looks like another 6 hr project. I am getting ready to get rid of these to get a car that gets better gas mileage. However I dont want to try and sell it with it the way it is. I have a F250 and need a car for the family because the truck only gets about 9mpgs and I am just trying to make this sale able. I do love the explorer but it only averages about 15 mpgs between hwy and city driving. Arrrggg.

 

Is the lower radiator hose and heater hoses getting hot? You may have an air pocket in the system.

 

Ok so I have found out that the little hose the goes into the
top of the thermostat housing is leaking looks like the hose clamp has broke off and is now leaking. So I am going to fix that. I have not checked the lower radiator hose. The heater hoses will get hot but not as hot has the top radiator hose.