Heating & Cooling System

[ss879237]

I am new to this forum so please help if you can I have a 2001 ford ranger xlt 4x4, my truck will not reach its operating temperature while driving, I have replaced the thermostat, fan clutch, water pump and both sensors on top of the thermostat housing. I have no clue what else could be causing this issue. When I sit at a red light it will slowly heat up until I start to drive again then it will cool down to just above the "C" on my temp gauge.

Thanks to whoever can help me out.

 

[adsm08]

Sounds like low coolant to me.

Postin' from teh Galaxy

 

[Earl43P]

I would replace the thermostat again.

 

[ss879237]

The coolant is full and I have made sure there are no air bubbles in the system,
I have changed the thermostat 3 times.

 

[robertc1024]

Sometimes getting air bubbles out of your system isn't so easy. Not trying to be a jerk, but how are you sure?

 

[ss879237]

I add coolant, then add more coolant while I have the heater on fill blast and burp the system by squeezing the upper and lower heater hoses. If there is another way thats easier im game.

 

[doorgunner]

It has taken me anywhere from 5 minutes to 45 minutes to get all the air out of the system WITH the heater on (and a partially clogged heater core makes the burping even harder to do).

What degree thermostat are you using now?

 

[RonD]

I am new to this forum so please help if you can I have a 2001 ford ranger xlt 4x4, my truck will not reach its operating temperature while driving, I have replaced the thermostat, fan clutch, water pump and both sensors on top of the thermostat housing. I have no clue what else could be causing this issue. When I sit at a red light it will slowly heat up until I start to drive again then it will cool down to just above the "C" on my temp gauge.

Thanks to whoever can help me out.

What size engine?
What is the average outside temp since this started happening?

The thermostat sits in a housing and it must be seated just right or coolant will bypass it so engine can never warm up.
I would double check the thermostat, I know it is a pain but the t-stat sets the minimum operating temp of the engine and that is what you are having a problem with.
Also Fords use 192deg or 195deg t-stat, not 160deg or 180deg, so check your receipt for what the last one is.
The t-stat should also have a "jiggle valve", it is just a hole in the t-stat plate to allow air out when refilling the system.
A 192deg t-stat means the valve will not start to open until the spring in the t-stat gets close to 190degs, so the spring side always goes towards the engine.

A simple test is to start the engine cold and feel the upper radiator hose, closer to the engine end, if it starts to get warm then t-stat is open or is being bypassed(not seated), the upper hose should have no circulation until coolant temp reaches 190deg, so hose will stay cold and then heat up quickly as t-stat opens at 190deg.
You can also remove the rad cap while engine is cold and watch the coolant as engine is running, it shouldn't be circulating.
The water pump only circulates coolant in the engine until the t-stat opens(190deg), then it starts to circulate through the rad.
If upper hose gets warm soon after starting cold engine or you see coolant circulating in the rad with cold engine, the t-stat will need to be looked at again.

Air in the system could cause cold heater air inside the cab, but in the engine an air bubble should cause overheating not underheating.

 

[ss879237]

Ok I finally figured out what was causing this problem:

It is a combination of two things 1) the heater core was/is partially clogged so I cut a short piece of pipe and disconnected it from the heater core and put the pipe in both hoses to loop the cooling system, (but your heater will not work). After doing this I discovered that my truck was getting hot like it was suppose to at idle.

2) After truck was warm during idle when I would drive down the road it would cool down my coolant and it would not reach operating temperature, so that means my fan clutch was staying engaged, and you can hear it when you start to go down the road which sounds like a big freightliner trying to accelerate, but once my fan clutch (torqflo from autozone just buy the motorcraft) disengaged the coolant reached operating temperature and gas mileage improved greatly and the fan clutch wasn't robbing any more of my horsepower.

I hope this helps anyone out there with the same issues I had.

2001 ford ranger 3.0 4x4
195 degree thermostat

 

[wildbill23c]

I had the heater core fail in my 84 Ford Bronco 2 about a month ago of course this only happens when the weather is in the negative digits and its snowing. I made it home from work with both windows rolled down to keep the steam from fogging up the windshield. It was a very cold ride home. It was dumping coolant on the floor of the cab.

Got the core replaced and it was overheating after that, got the air bubbles purged out of the system and it works just fine now, so when you replace your heater core make sure you purge all the air out or you'll still have an overheat problem until you do.