so i recently bought an 01 4 cylinder 2.3 ranger and im having a bit of an issue with it... when i purchased the truck the temp gauge was not reading AT ALL and the pervious owner simply said that the coolant temperature sensor had gone bad needed to be replaced. There was no check engine light (im assuming he wiped it) and the truck ran just fine with no unusual signs of overheating. I drove it home (about a 15 mile drive) without issue. Now right away I went and tried replacing the CHT sensor because it was much easier to get to and i figured it was worth a shot as it was cheap and easy to replace. I made some progress! after replacing the cylinder head temp sensor the gauge would read but not accurately, the needle only would make it just a sliver above the bottom "C" marking before stopping and now throwing a check engine light. hmmm.. I took the truck to autozone and got it scanned. they sent me home with a new coolant temperature sensor and i figured that would be it. 1 hour of struggling and moving wires around later the new plug was installed and there was a nice pool of coolant on my driveway! However this is where my issue comes into the picture... after all that i jumped back into the truck (after topping off the coolant level of corse) and took it for a nice long drive around the neighborhood and now the temperature gauge is not reading at all? i had the code cleared for the check engine light and it has since not come back on but i really have not driven it much so im unsure if it will or not. this really confuses me and im not entirely sure what to do next, my best guess would be to go back to autozone and get another sensor? I've never been sold a faulty part from them before so I'm not entirely sure that's the issue but id like to hear some suggestions from someone with more experience than me first! anything helps! thanks...

 

Welcome to the forum

You have a 2.3l DOHC Duratec engine, so a late model 2001 Ranger, early 2001's had the 2.5l SOHC Lima engine, totally different engines, just FYI
So to not confuse auto parts guys, lol, tell them to look up 2002 Ranger 2.3l for parts, Ford use same engine that whole year and until 2011

The 2.3l Duratec used a CHT(cylinder head temp) sensor for the computer, not for the gauge, no connection to the temp gauge at all

Then it has a Coolant temp SENDER, but often wrongly called an ECT sensor
Senders is 12volts
Sensors use 5volts
So not at all the same

This SENDER is located on passenger side rear of engine on a metal coolant pipe.
It will have a Red/white wire and a Black/white wire
Red wire runs to the dash and computer, its powered by the dashes 12volt power, fuse 11 in cab panel
Black wire is a Ground

Diagram below

The 2.3l sender does use an added Resistor located in engine fuse box, this is because its located in the rear of the engine so standard Ford gauge would read low because coolant at the rear of the engine is not as hot as it would be at top front of the engine, where most temp sender are located

Temp gauge would still work if resistor was bad, it would just read low, maybe under 1/4 instead of just under 1/2

Look at lower right on diagram for SENDER, look for the 2.3l wiring its different than the 3.0l/4.0l V6 wiring
Power control module(PCM) = computer

 

thank you very much for the information! i noticed the guys at autozone were having a very hard time finding any parts for my truck and the fact that i have a late model might be the case... it makes total sense now. I will go back in and get a tempature sender instead of a sensor this time and replace it. will post my findings as soon as the job is completed. again, thank you very much for the information!!

 

And a couple of Heads ups

2.3l duratec has been a very reliable engine, similar turbo version is used in the new 2019 Ranger, 2.3l Ecoboost

2001-2003 models had an electric thermostat, a heated thermostat, and it is expensive to replace, its on lower rad hose not upper
These years also have IMRC(intake manifold runner control) it was a good idea that didn't work, it can give you problems
2004 and up didn't have either of these

All years, 2001-2011, 2.3l Duratecs have a coolant hose fitting in the back of the head, and you can not get at it if it leaks, so if for any reason the transmission is pulled back or out change this hose and fitting, just because, lol
The 2.3l Duratec is the Mazda L engine and was designed to be mounted sideways in a car, so coolant hose on the back of the head would not be hard to service
But when put in a Ranger it is very hard to get at

 

today was the day that i finally got around to testing out the new installed parts. auto zone definitely sold me the wrong part, i got the oem motorcraft sensor and reinstalled it. however it still has the same problem as before (reading abnormally low on the dashbord) so basically my coolant temp sensor was never faulty in the first place. damn... check engine light continues to stay on for faulty coolant temperature reading. There is one new thing have found however. when i turn the truck off and let it sit for 5 or so minutes then turn the ignition back on, the temp gauge will read normally! ( about half way between the C and H markings where i suspect it should normally be once at operating temperature) but when i start the truck, it slowly sinks back down to below the C marking again on the gauge. could this be a lack of pressure? or maybe a blocked passage way in the coolant system? i figured there just is not enough coolant actually getting to the sensor for it to read at all... and when the truck is off the coolant isnt circulating so it bubbles up and contacts the sensor, allowing it to finally read? A friend of mine who also owns a ford ranger told me it could be a worn coolant pump as my heater is not as powerful as it should normally be also. could it be the thermostat? im unsure where to start looking haha.. again any advice will help. thanks!

 

So you changed the Sender that is on the coolant pipe at the rear of the engine?

There is also a Resistor in the engine fuse box, location #43, that makes the gauge in the cab reading higher(normal)

 

Yes, the sender was replaced with the oem motorcraft part, and i made 100% sure the part was a sender not a sensor. however as far as that resistor... i didn't remember to replace that. just a little bit ago i went down to the ford dealership and i took them that exact part. they gave me a cross reference number and basically sent me out the door with no help. i was told the part was obsolete and the best bet i had at finding a replacement was ebay??? after about 2 hours of research i found absolutely nothing on the part or even any sort of aftermarket replacement. another thing i forgot to note from before aswell was that the coolant temp gauge tends to fluctuate from below the C marking all the way to a quarter of the way up the gauge reading as i drive around. its very random and the only pattern i can notice is it seems to read hotter when im at stop lights for long periods of time... anyway, very confused at this point.

 

Not that anyone will see this, but the solution to my issue ended up being a thermostat!

 

Thanks for the update and FIX

Yes, people searching, that have similar issue, will see this and it will help them

 

Evening Gents,
I too seem to be having a issue with my ECT, every thing I'm seeing points to the ECT. The temp runs fine but then suddenly spikes that it's running way to hot, then it drops back down to normal operation. As for actually overheating, it doesn't seem to be. Everything I've checked points to the ECT, but I'm unable to find it, despite having been over, under and in between. Alas I don't have a late model 2001, but mine was manufactured in March, so I'm thinking I have one of those early engines you spoke about. Any help you could give me would be appreciated.

 

Welcome to the forum

You should always start your own thread

You have a 2001 2.3l Ranger, should always include that as well, lol

ECT sensor is for the computer and you don't have one in a 2.3l Duratec engine, its a CHT(cylinder heat temp) sensor that only the computer uses
The dash board temp gauge uses a temp sender not a sensor, yes they are different, sender is 12volt and all sensors are 5volt or less, just FYI

On the 2001, and up, Ranger 2.3l Duratec engine's the temp sender is on a hose/metal pipe behind the head next to the firewall, hard to see
It has 2 wires connected
It is only used for the temp gauge on the dash

As for the swing in temp on the gauge, that could be the temp sender, but...............it could also be the Thermostat starting to fail
2001-2003 Ranger 2.3l used a heated thermostat which are expensive to replace
And if you don't think the temp is actually going high then I would replace the temp sender just on speculation

You could have the heater on and then feel the air coming out when temp gauge spikes to HOT, if air temp is not getting hotter then its most likely a temp sender issue not actual overheating
If heater air temp gets COLDER then you are low on coolant which is why the gauge showed Hotter

 

But.. it's the EXACT same thing that starts this thread! I ripped the theromstat off and it looks fine, I even flushed it with headed water and it works perfectly allowing more water through. I still can't find that ECT Sender.

 

Doesn't matter, threads are free to start, and what happens is they can go off course if others "with the same problem" start asking about their problem
And if yours is the exact same problem then the answers in this thread would have fixed it, right?

It's not a big deal, most help forums ask members to start a new thread even if same thing has been asked repeatedly

Here is a picture of the temp sender: https://cimg6.ibsrv.net/gimg/www.ran...22cef5884e.jpg

That's spark plug #4 wire on the left and Cam sensor on the right, with temp sender connector in the center
Red/white and black/white wires
So very back of the engine by the firewall, PITA to get to

Picture is from post #21 in this thread: https://www.ranger-forums.com/dohc-2...t-sensor-8063/

This thread also shows the CHT sensor location, this sensor could act up, or fail outright, so keep its location in mind