Hi there!
I bought 2007 ford ranger with 4.0 SOHC engine about a month ago. The owner had a new radiator installed 2 months ago. Apparently there was a code coming up here and there saying the engine is running colder than normal operating temperature. I don't know if the code was coming up before or after the radiator replacement. Their mechanic recommended replacing the thermostat housing as well as the thermostat. So I decided to replaced both of them a couple weeks ago. I also put the original sensor into the new housing. I had driven it about 250 miles with no issues until yesterday. I was driving for a few hours and then the overheating light came on so I pulled over and let it cool down. There was no sign of it overheating other than the gauge. There was no leaks, no strange sounds, cap was fine and the coolant was full. I decided to try to drive again after cooling down but the temp gauge was increasing past middle again. I had about 1-2 minutes of driving and then would have to let it cool for 15 minutes. I did this about 8 times till was able to get to a mechanic. The mechanic had a look at it this morning but said they couldn't get it to overheat. They are recommending a new thermostat housing because they believe it's not the right housing for the truck but it's identical to the previous one. This doesn't seem like the issue to me. So I'm thinking it could be that the thermostat is faulty or sensor. Since the mechanic hasn't be able to get it to overheat, l'm thinking of driving it back home which is about 3 hours and then replacing thermostat or sensor or both. I would like your guy's input on what it could be.

Thanks!

 

Welcome to the forum

There is a metal thermostat housing now available for the 4.0l SOHC much better than the plastic Ford model, just FYI

When engines first got Fuel injection they needed a Temp Sensor for the computer, so the 5volt ECT(engine coolant temp) sensor was added
Engines already had a 12volt temp sender since the 1930's for a dash board temp gauge
So there were 2 temp devices on any fuel injected engine for 20+ years

In 2007 Rangers Ford dropped the 12v Temp sender and the computer used the 5v Temp Sensor and then sent that temp to the dash board gauge
If the engine is not actually overheating, i.e. heater blowing cold(low coolant) or blowing way too hot actual overheating, I would change the ECT sensor, easy to do, l as the first thing
If you still get overheating on the temp gauge then you can do the thermostat


New parts are no longer trustworthy, i.e. "new thermostat", if a shop installed it its most likely a good brand
You have a better chance with Motorcraft parts but they cost more because Ford still requires Quality Control on all parts, i.e. tested and works
3rd party are cheaper but also at the cost of a warranty(for them), if 25% fail, under warranty, they are still are making money, and your labor is FREE, to them
Just a heads up

 

This has been really helpful, I will start with the sensor first. My ranger is the 1 sensor housing and I am wondering if I could grab a sensor from a housing with 2 sensors at a salvage yard?

 

Yes, you can try a used one but get BOTH sensor and sender if there are two, so you will have the right one for sure

Save the old one in case you do get the metal housing in the future, it may have the two holes, and you can use the extra sensor to plug the hole

 

Okay I will give it a shot, thank you!

 

Hey so now Im thinking of just putting a new aluminum housing in since I'm already going to be replacing the thermostat.
My mechanic is saying that the housing I got is wrong because it has 2 sensors but I left the 2nd sensor as a plug like you said.
I couldn't find any aluminum housing with one port so I am assuming that I can use a 2 port housing and just plug the one with a sensor/plug without any issues?

Heres the link to the thermostat housing I am thinking of getting

 

Yes, as far as I know the metal housings all have 2 sensor ports because that can be used on any year, just use the old sensor to plug the 2nd port as before

 

I picked up my truck up from the mechanic and the engine started to overheat again.
I pulled out the thermostat and sure enough the thermostat had wax leaking out of it.
Put a new thermostat in and has not overheated since