I installed the new thermostat into the thermostat housing.
HOWEVER: I’ve filled the truck up with coolant at the radiator with the cap off and started the truck, then turned on the heat (it’s only blowing cool air...?). After about 5 minutes my temp gauge is still at C and the level at the radiator is still at the brim. No heat coming out of the vents in truck. I tried my best to instal the thermostat like videos and instructions say...what could be my issue?
Thanks

 

you need to give the engine time to warm up, usually it takes about 10 mins or so for a stat to open especially on an old cast iron engine

 

If engine has cooled down
Remove 1 heater hose at the firewall, either one
Then refill via radiator until coolant comes out that hose and the port in firewall(heater core)
This releases the air that is TRAPPED behind the CLOSED thermostat

Air will be trapped in upper engine area, where the thermostat is, and thermostat can't react to Air Temp, just coolant temp

The air in the heater hoses also forms an air dam, the water pump can only pump fluid, and air will not be pumped thru so no circulation thru heater hoses

 

Okay, I removed one of the hoses from the firewall, radiator cap off and full to the brim. Some fluid came out at the firewall but I started the truck to make sure coolant was actually coming out. Plenty shot out at the firewall and the hose there lol...not sure if I did that right but eh. While coolant was coming out I reattached the hose to the firewall. Temp gauge is still at C and after about 10 minutes of trying to let the engine warm up, the air blowing out of the AC is still cold even though put to hot on the control ****...no coolant is going down at radiator, still full to the brim. Could this be an issue with the heater, or perhaps an issue with the installation of the thermostat. Perhaps I need to take the truck for a drive, and let the engine REALLY warm up? It has been maybe 40 degrees here the last few days.

 

Feel the heater hoses, both should be hot after 4min
The TEMP selection in the cab just opens and closes a door in the cab, doesn't control anything in the engine bay

You should have shut off the engine, before putting hose back on, you just sucked more air in on the open ended hose

What year and what engine in your Ranger?

 

I’ve got a 1989 2.3l 4 cylinder ranger

So I disconnected one of the two hoses at the firewall, started the truck, let fluid run out both the hose as well as at the firewall. Then I turned the truck back off, and reconnected the line. Is this correct?
I filled the radiator back to top, and then took the truck for about a 15 minute drive. Temp sensor in truck is still on C and I’m not feeling any warm air come out of the vents. However it does seem that those two lines at the firewall are beginning to warm up to the touch.

 

????

No, you don't start the engine with a heater hose disconnected
You just disconnect either hose and fill the system via radiator, when coolant start to come out the hose and heater core put hose back on, all the air is out

 

Radiator cap is off and filled to the top. One heater hose is removed at firewall and no fluid drains out. Radiator fluid level stays the same during all of this. I think this is where my confusion begins, maybe my lines are set up wrong, or thermostats in the water pump is not functioning correctly? Just all my thoughts based on what I sort of understand...this is all being done while the truck is off and stays off.
When I got this truck, one of the two heater hoses from the firewall was cut very close to the wall and a huge section of the hose was missing...therefore I took a piece from another ranger at the salvage yard and made the connections where needed.

 

Well the hose that's off needs to be at the same level or lower than rad cap opening for coolant to flow out
So if you are parked facing down hill then coolant couldn't flow "uphill" to come out the hose or heater core

You are just trying to get "most" of the air out, the rest will come out when engine is running

Thermostat blocks UPPER rad hose(on most engines), so coolant will flow into the engine thru lower rad hose pushing any air out of the unhooked heater hose
If heater hose is not unhooked the air can't get out, so its trapped in upper part of engine and heater hoses

 

The first two photos are how my coolant hoses are set up currently.
The third photo is how the hose was cut when I got the truck.
The fourth photo is of a truck I found online and has me questioning if I connected my hoses correctly.
Not sure if it is clear enough but I’m wondering if I’ve got it right or not?
Also wonder if I need to mess with my temp sensor?
I’m not experiencing any bad sounds, just no heat blowing in truck when turned on, and temp gauge is ALWAYS on C, never moving with prolonged running of the truck.

 

Not following the routing

In all engines there would be a "heater" hose from near thermostat housing on the engine to Firewall heater core(sends heated coolant to heater core)
Then another "heater" hose from Water pump to firewall heater core(water pump PULLS in heated coolant from heater core)
Doesn't matter which hose is which at the heater core, and these should actually be reversed every 2 years when you change coolant, that keeps the heater core cleaner by "back flushing it" while driving

Then some engines have "T's" on the heater hose that go to the intake manifold and/or PCV Valve pre-heaters

Also 1995 and up Rangers often have 4 hose By-Pass Valve on the heater hoses, this is activated only when AC MAX is selected in the cab, it cuts off hot coolant flow thru the heater core for max cab cooling
It's a vacuum operated valve
2 hose IN, 2 hose OUT

 

Okay, seems my hoses should be set up correctly.
My big concern, the dash Cold/Hot meter does not move at all, it stays on C even after an entire 20 mile trip. I know this cannot be right. Could the thermostat be stuck open, or perhaps closed? When putting the truck back together I used the original and very dinged up thermostat housing and I'm wondering if the thermostat is not able to move open and closed as it is supposed to. Should I replace the thermostat housing for safe measure?

 

Was the top radiator hose hot?
Did you have heat in the cab?

If so then temp sender may just be unplugged or bad

 

I would be very conscious of the testing you’re doing. I know these engines are tanks but it makes my stomach turn thinking of you driving around and the head of the engine isn’t getting any circulation of coolant.

The only thing I could think of is if your thermostat is placed in correctly. I once had a nightmare of a time getting an engine back together(Ford 300) because once I had the thermostat housing in, the t-state would fall oh so slightly to the point where it was enough to throw off the whole thing.

Im more surprised that your radiator isnt spewing hot uncirculated coolant. Like someone mentioned before, check the sensor for the temp and maybe bang on that dash a couple times.

 

So from what I remember, the top radiator hose was hot, and the cab was getting warmer air for sure, I wouldn’t call it heat. I replaced the thermostat temp sensor very recently so I’m surprised I might be having an issue there? I checked and it’s connected...could I have installed poorly (though that seems impossible) or perhaps the part is bad?
I really haven’t been doing any other “tests” as I too am extremely uncomfortable driving the truck and causing serious damage.
I’m going to just go ahead and replace the thermostat housing and double check that the thermostat is in correctly.

 

There are two temp units on most engines now

Temp sensor is only used by the engine computer, 5volt, always 2 wires, added when engine computers were first used, in the 1980's

Temp SENDER is only used by dash board temp gauge, 12volt, can be 1 or 2 wires, this is what all vehicles had since the start of dash board temp gauges, 1930's???

 

Did you use a Ford thermostat or and after market one? I had trouble with a number of after market thermostats in my 98 with 2.5 engine. I finally broke down and bought the expensive Ford thermostat and haven't had a problem with engine temperature since. Just a thought.

 

Just replaced the second temp sensor, still no change on the dash. Still at "C". Tomorrow i'll replace the thermostat housing and the thermostat in hopes that something new happens...
I don't know, running out of ideas and would hate to destroy the engine! The top radiator hose was hot today after installing the new sensor and running the truck for 5 minutes.

 

Upper rad hose shouldn't get hot that fast, it means thermostat is open

The heater hoses should warm up with the engine, they have coolant flowing thru when ever water pump is working
The upper(and lower) rad hoses only have coolant flow AFTER thermostat opens a bit when coolant gets above 185deg or so
So upper rad hose should remain cold for 5-8minutes of idling, under a load the coolant may warm up faster but at idle engine doesn't generate the extra heat

Radiator is there for EXTRA heat, in extreme cold climates it may not even be used, the thermostat is there to decide when there is EXTRA heat, it controls the flow thru radiator, upper hose hot coolant IN, lower hose 15-20deg cooler coolant OUT, to water pump

Remember to pull off one of the heater hoses at the firewall when refilling the system, that lets the air out of the engine side of thermostat
When coolant starts to come out of heater hose, and heater core, put hose back on, the air is OUT

 

Okay, back again after taking time to troubleshoot and let things sink in.
Ugh I cannot figure this out.
ISSUE: Dash board temp gauge stays on "C" no matter what I try.
With engine off, reading is C. With engine on and running for 10, 20, or 30 minutes...still C.
I replaced both the temp SENDER and the SENSOR. SENSOR has a clip connector and the SENDER has a single wire metal head type connector.
Temp SENDER is back of engine bellow oil pressure sensor. Temp SENSOR is nearer to the front of engine under the driver side exhaust manifold.
I went ahead and removed and replaced the NEW thermostat as well, to ensure I had installed it correctly. The new thermostat was covered in gunk as this truck sat for five years prior to me getting it.
So with NEW NEW thermostat installed in the correct direction, and the two new sensor/sendors installed and connected...and with the coolant system bled correctly to the best of my knowledge in reference to the above directions...I am left scratching my head.
When I bleed the system by removing one of the hoses from the firewall, coolant will run out of the hose and the radiator level lowers. HOWEVER coolant does not run out of the firewall. It isn't supposed to drain out of the firewall am I right? Because it is higher than the radiator and air would not travel in that direction?
One last thing...I believe that I may have installed one or both of the temp sensors/sendors with some of that white threading tape. I believe I read on one of your other posts RonD that this is not a good idea and keeps from getting an accurate reading?
MY QUESTIONS: Is my coolant system bled correctly and running as it should to cool the engine/how can I know for sure. Is my dash gauge related to the system not cooling correctly? Is my thermostat stuck open, even if it is brand new? The top hose from radiator to the thermostat is usually warm or hot in the first 5 minutes...
I feel that if I could get my dash gauge working, then I would be able to use that as a tool to tell if my system is cooling like it should...
Long post, thanks in advance.
Should I just take this to a mechanic at this point? I am determined, but perhaps there is a quick way for a mechanic to determine my issue? What would I tell them, how would THEY check??

 

1989 2.3l 4 cylinder ranger

The coolant SENDER will have just one wire attached, its on drivers side toward rear of engine
You do NOT want to tape the threads on this sender as it uses its threads as a GROUND point so it can work with just 1 wire

The ECT sensor has 2 wires so you can tape the threads if you want

To test the wire and temp gauge you will need a separate wire(jumper) that's long enough to reach Battery Negative terminal, a good ground
COLD ENGINE and Key OFF
Hook the "jumper" wire to Battery Negative, or any good ground point
Unplug the temp sender wire
Hook jumper wire to sender's wire so it makes good contact to the metal end of sender wire
Turn the key on, engine OFF, and watch the temp gauge, it should go to HOT, all the way up, this means wire and temp gauge are OK
If needle does NOT go to HOT then wire or gauge is the problem not the sender on engine

If temp gauge does go to HOT then wire and gauge are OK, sender is either not grounded or its bad


Coolant may or may not come out of disconnected heater core port when refilling with heater hose off
That depends on how the truck is parked, uphill or downhill angle, if heater core port is higher than rad cap then no coolant would come out, but air in the core would be pushed out so coolant was at rad cap level inside the core, so very little air would be trapped inside, and a little air is OK, cooling system can flush that out when in operation
What you want to avoid is alot of air trapped in heater core and its hoses, so removing 1 hose at the firewall releases most of the air while refilling

 

Right on, very helpful! I checked the coolant SENDER by using a wire connecting the metal end of sender wire and the negative battery terminal. The temp gauge on the dash went right up all the way to HOT like you said it would if wire and gauge are good.
I removed the current sender and it had white tape on the threads. I went back to the store and got a new sender, this new one also came with white tape on the threads. So I removed the white tape, and installed the new sender. However, dash is still showing C and not moving at all even after about 5 minutes of letting the engine run. Previous to replacing the sender, I started the engine and let it run for a bit, then I removed the old sender. I could feel that the coolant had gotten warm, as it ran out of the hole. Should I try letting the truck run longer, or take it for a drive? If the test showed wire and gauge are good, and if the sensor is new, what is left? No ground? Something other internal issue? Top hose to radiator and thermostat was hot again after about 5 minutes running.

 

I did a full flush of the hoses and radiator yesterday, hooked everything back up, and filled with coolant. Started the truck and although it is showing the SMALLEST sign of life on the dash gauge, something is still not working. The top radiator hose is getting very hot very quickly. I am led to believe that this has to do with the thermostat malfunctioning and or not allowing coolant to flow correctly. This could also effect the temp gauge on the dash, from what I was reading? The thermostat is brand new out of the box, and I installed it in the correct direction with the spring facing the engine, however perhaps It is the wrong thermostat or it has fallen back into the engine, allowing coolant to flow freely as the engine runs? Does this ring any bells? Could it not be snug as it should be, and therefore allow coolant to flow past it as the engine runs? I cannot find any photos online of my engine. A 1989 ranger 2.3 liter 4 cylinder. Some other year rangers show that the thermostat fits perfectly into the cylinder head hole, however on MY cylinder head, the thermostat doesn't line up perfectly. The thermostat fits in my stock ford thermostat housing, but something is wrong with the other end connection, between cylinder head, and back side of thermostat?

 

Also, could my heater core be the/A problem? Could it be bad?