Low speed cooling fan not coming on when car comes up to temp

[Rc1919]

I drove for 10 hours on an 80 degree day, when I got home I had lost some coolant, it was below the minimum line. I topped it off and drove it the next day and drove around at 45 speeds, coolant temperature readout on the secret menu would get up to 95+c. I had a blown fuse, unsure if the fan relay also on the outside box was bad but I got new ones. I replaced the fan assembly and "resistor block" in the interior, it did not look bad or the pins on the connector. I test drove the car and it would run fine around 84-86c on the highway but then I parked at a store after driving about 8 miles, the temperature continued to rise until I shut it off. The fan has come on before and after I replaced it when I would turn on the defroster or the ac and when the car would be started if the temperature was somewhat warm it would come on for a bit at first and bring the temperature down then shut off. . I have had intermittent cold ac but it started working again and better it seemed for now after the repair. I tried to burp the cooling system as well by squeezing the upper hose. Computer at AutoZone showed a code for the O2 sensor, with 3 secondaries: lower than expected coolant temperature, map/maf sensor and another one I lose the paper, which led me to believe the O2 sensor got hot that's why it threw the code and it had low coolant, perhaps it had gotten hot then sprayed off on the over spray valve and there was loss of power because the car was running harder hence map and maf codes. I have not been able to find anything else except for possibly coolant temp sensor, thermostat, or a wiring issue. I had the problem about 8 months ago where my car actually gave a warning light for overheating and I took it to shop and it was fixed with a fuse. Its ran fine since then , 3 months prior to that it got a new water pump and timing belt etc.

 

[Handy Andy]

You have to figure out why that thing is losing coolant.

The thing may have a blown gasket - leaking combustibles into the coolant with the coolant boiling off, in-foam out the tank.

Look for white residue where the hoses are connected.

The initial overheat signal may be the tell-tale of more work in the cooling system has to be done.

Did they do a flush of the cooling system too?

 

[Rc1919]

I don't remember if they did a flush of the cooling system when the water pump was replaced but they did service the cooling system and put all new coolant in them system and I flushed it about 6months after that. About 3 months ago I did an exhaust fumes test on the coolant reservoir with a kit and dye from harbor freight and did not find anything abnormal. Why won't the fan come on then ? You think that could be related to the coolant system not hitting some kind of sensor or something ?

 

[Handy Andy]

IF the relays are fine - then it's possible, a long shot, but possible the "override" switch in the sensor burned up from the trigger to set off the relay - which can burn out i time because it forces the Fan relay on - it does have current thru it - the wire is small gauge designed for intermittent use, not all the time - else it too, can blow open - it depends on if you have single wire or dual wire or triple wire - even four wire (with temp sensor included)

Be careful with this.

There are several "Variants" of the Cooling Fan.

If you have a 1.0L Ecoboost motor - 3-cylinder - it uses a Fan/Resistor/Relay-to-Resistor(LO)/Relay-to-Fan-bypass(HI) speed system - so you have TWO relays in the engine compartment. It also has Shutter and cooling pump in the engine bay.

​

IF you have the SE with the 1.6L TiVCT you have 1 relay and the PCM controls the relay no variable speed...

​

If you have the GTDI (Direct Inject no fuel rail just line to top of motor with a big thingy on the side of the motor that pumps the fuel in there) it has injectors in the cylinder head directly inside the chambers spraying fuel. It uses a MODULE on the Radiator shroud housing that determines the temp at the radiator - and the PCM controls it directly.

​

You'll have to choose your poison...

There is only one ECT in 2013 (the new Nose Job ones and later) - goes to the PCM

I don't know of the ECT wiring in the 2011....

I hope the above gets you started...

 

[Rc1919]

I really appreciate

IF the relays are fine - then it's possible, a long shot, but possible the "override" switch in the sensor burned up from the trigger to set off the relay - which can burn out i time because it forces the Fan relay on - it does have current thru it - the wire is small gauge designed for intermittent use, not all the time - else it too, can blow open - it depends on if you have single wire or dual wire or triple wire - even four wire (with temp sensor included)

Be careful with this.

There are several "Variants" of the Cooling Fan.

If you have a 1.0L Ecoboost motor - 3-cylinder - it uses a Fan/Resistor/Relay-to-Resistor(LO)/Relay-to-Fan-bypass(HI) speed system - so you have TWO relays in the engine compartment. It also has Shutter and cooling pump in the engine bay.

View attachment 8186
​

IF you have the SE with the 1.6L TiVCT you have 1 relay and the PCM controls the relay no variable speed...

View attachment 8187
​

If you have the GTDI (Direct Inject no fuel rail just line to top of motor with a big thingy on the side of the motor that pumps the fuel in there) it has injectors in the cylinder head directly inside the chambers spraying fuel. It uses a MODULE on the Radiator shroud housing that determines the temp at the radiator - and the PCM controls it directly.

View attachment 8188​

You'll have to choose your poison...

There is only one ECT in 2013 (the new Nose Job ones and later) - goes to the PCM

I don't know of the ECT wiring in the 2011....

I hope the above gets you started...

Thank you for your help and expertise I really appreciate it. I also added a bit of uv dye to the coolant before I flushed it on my own and I could not find a leak with the uv glasses/light

 

[Handy Andy]

As you can tell in the above, the "Color Code" for the wires used, each "system" is colored differently so you could recognize it by the colors in the wiring harness to it - they made it specific for the various engines used, specifically for this reason - to help identify the cooling systems' just by the color of the wiring used.

 

[dinozosfed]

IF the relays are fine - then it's possible, a long shot, but possible the "override" switch in the sensor burned up from the trigger to set off the relay - which can burn out i time because it forces the Fan relay on - it does have current thru it - the wire is small gauge designed for intermittent use, not all the time - else it too, can blow open - it depends on if you have single wire or dual wire or triple wire - even four wire (with temp sensor included)

Be careful with this.

There are several "Variants" of the Cooling Fan.

If you have a 1.0L Ecoboost motor - 3-cylinder - it uses a Fan/Resistor/Relay-to-Resistor(LO)/Relay-to-Fan-bypass(HI) speed system - so you have TWO relays in the engine compartment. It also has Shutter and cooling pump in the engine bay.

View attachment 8186
​

IF you have the SE with the 1.6L TiVCT you have 1 relay and the PCM controls the relay no variable speed...

View attachment 8187
​

If you have the GTDI (Direct Inject no fuel rail just line to top of motor with a big thingy on the side of the motor that pumps the fuel in there) it has injectors in the cylinder head directly inside the chambers spraying fuel. It uses a MODULE on the Radiator shroud housing that determines the temp at the radiator - and the PCM controls it directly.

View attachment 8188​

You'll have to choose your poison...

There is only one ECT in 2013 (the new Nose Job ones and later) - goes to the PCM

I don't know of the ECT wiring in the 2011....

I hope the above gets you started...

Hello guys...
my fiesta is seems like having this kind of problem. which is, after drive the car about 10 to 15km n then the car park, engine idling about 10 minutes the engine temp started rise quickly to the max. For info coolant not loss. the engine temp is ok when the car is moving.. suspect the fan motor, but the fan still running when engine idling. tried changed fan resistor but still the problem occur.. wondering if there is any possibilities my relay or any fuse is the culprit?

 

[Handy Andy]

How long since you've done a coolant flush?

There are several "directions" we can take with this but to keep it simple...

How many miles on the car? Why? Well, over 80,000 miles and several years - the Water pump can fail - or become worn - you own a turbo so cooling the system down after each run is (can't stress this enough) extremely important. If the water pumps' impeller is worm or the bearings drag, it can even affect the ability of the serpentine belt to keep everything else spinning and doing their job.

• Don't always presume the Electrical part of the system is the culprit.
  • Yes - Fans require electrical power to operate and the make the sensors do their job - but the issue of no fan - but you can engage it using the AC side - then the Relay might not be the problem.
  • When you have a "hot motor" that coolant can also boil and form pockets where air - as steam - can get trapped or worse the sensor can become inoperative.
  • To test the sensor, pull the wire to it, does the fan now click on? Then the issue is at the sensor - the sending unit itself is not working or providing "Range" of profile for the system to determine there is too much heat sooner than later.

The symptoms may also be from a radiator that has debris or is plugged from oil that can seep past the head gasket at the same time the seal the gasket has let the combustion chamber gasses leak into the coolant in the engine jacket.

The process is simply from too much pressure - when you engage the turbo - especially for long or hard runs, might also leak past the cylinder head gasket from the combustion chamber - into the coolant - pressurizing the fluid and also forcing oil to mix in with it - forming a type of foam that when it gets into the core fin tubes of the radiator can slow down the circulation or even plug the tube - requiring replacement of the radiator or at least a good flush and refill.

There is a "burp tube" located from the rear exhaust header side - towards the Brake master cylinder - the tube bleeds off air that collects from the boiling - and routes thru this tube to the coolant tank. Some Ecoboost engines do this up differently so look for your coolant tank and locate all those hoses - and find the one that has the highest elevation in your engine compartment - that heads to the coolant tank from some remote spot on the motor - that one burps the system.

The easier way to check for built up pressure - is to simply watch for bubbled fluid and foam to rise up from the main hose to the coolant tank from the the connector tee - while unscrewing the cap when the engine has idled down and you've run the AC to kick the fan on to cool down the fluid so you can check for that pressure.

If you've run it hot and used the turbo often - this should also change the fluid level quite a bit when you release that pressure after such a run. It would "deflate" the coolant tank, but also let the pressure equalize, displacing fluid back into the motor

 

[dinozosfed]

How long since you've done a coolant flush?

There are several "directions" we can take with this but to keep it simple...

How many miles on the car? Why? Well, over 80,000 miles and several years - the Water pump can fail - or become worn - you own a turbo so cooling the system down after each run is (can't stress this enough) extremely important. If the water pumps' impeller is worm or the bearings drag, it can even affect the ability of the serpentine belt to keep everything else spinning and doing their job.

• Don't always presume the Electrical part of the system is the culprit.
  • Yes - Fans require electrical power to operate and the make the sensors do their job - but the issue of no fan - but you can engage it using the AC side - then the Relay might not be the problem.
  • When you have a "hot motor" that coolant can also boil and form pockets where air - as steam - can get trapped or worse the sensor can become inoperative.
  • To test the sensor, pull the wire to it, does the fan now click on? Then the issue is at the sensor - the sending unit itself is not working or providing "Range" of profile for the system to determine there is too much heat sooner than later.

The symptoms may also be from a radiator that has debris or is plugged from oil that can seep past the head gasket at the same time the seal the gasket has let the combustion chamber gasses leak into the coolant in the engine jacket.

The process is simply from too much pressure - when you engage the turbo - especially for long or hard runs, might also leak past the cylinder head gasket from the combustion chamber - into the coolant - pressurizing the fluid and also forcing oil to mix in with it - forming a type of foam that when it gets into the core fin tubes of the radiator can slow down the circulation or even plug the tube - requiring replacement of the radiator or at least a good flush and refill.

There is a "burp tube" located from the rear exhaust header side - towards the Brake master cylinder - the tube bleeds off air that collects from the boiling - and routes thru this tube to the coolant tank. Some Ecoboost engines do this up differently so look for your coolant tank and locate all those hoses - and find the one that has the highest elevation in your engine compartment - that heads to the coolant tank from some remote spot on the motor - that one burps the system.

The easier way to check for built up pressure - is to simply watch for bubbled fluid and foam to rise up from the main hose to the coolant tank from the the connector tee - while unscrewing the cap when the engine has idled down and you've run the AC to kick the fan on to cool down the fluid so you can check for that pressure.

If you've run it hot and used the turbo often - this should also change the fluid level quite a bit when you release that pressure after such a run. It would "deflate" the coolant tank, but also let the pressure equalize, displacing fluid back into the motor

Hi there.. really appreciate ur reply

 

[dinozosfed]

How long since you've done a coolant flush?

There are several "directions" we can take with this but to keep it simple...

How many miles on the car? Why? Well, over 80,000 miles and several years - the Water pump can fail - or become worn - you own a turbo so cooling the system down after each run is (can't stress this enough) extremely important. If the water pumps' impeller is worm or the bearings drag, it can even affect the ability of the serpentine belt to keep everything else spinning and doing their job.

• Don't always presume the Electrical part of the system is the culprit.
  • Yes - Fans require electrical power to operate and the make the sensors do their job - but the issue of no fan - but you can engage it using the AC side - then the Relay might not be the problem.
  • When you have a "hot motor" that coolant can also boil and form pockets where air - as steam - can get trapped or worse the sensor can become inoperative.
  • To test the sensor, pull the wire to it, does the fan now click on? Then the issue is at the sensor - the sending unit itself is not working or providing "Range" of profile for the system to determine there is too much heat sooner than later.

The symptoms may also be from a radiator that has debris or is plugged from oil that can seep past the head gasket at the same time the seal the gasket has let the combustion chamber gasses leak into the coolant in the engine jacket.

The process is simply from too much pressure - when you engage the turbo - especially for long or hard runs, might also leak past the cylinder head gasket from the combustion chamber - into the coolant - pressurizing the fluid and also forcing oil to mix in with it - forming a type of foam that when it gets into the core fin tubes of the radiator can slow down the circulation or even plug the tube - requiring replacement of the radiator or at least a good flush and refill.

There is a "burp tube" located from the rear exhaust header side - towards the Brake master cylinder - the tube bleeds off air that collects from the boiling - and routes thru this tube to the coolant tank. Some Ecoboost engines do this up differently so look for your coolant tank and locate all those hoses - and find the one that has the highest elevation in your engine compartment - that heads to the coolant tank from some remote spot on the motor - that one burps the system.

The easier way to check for built up pressure - is to simply watch for bubbled fluid and foam to rise up from the main hose to the coolant tank from the the connector tee - while unscrewing the cap when the engine has idled down and you've run the AC to kick the fan on to cool down the fluid so you can check for that pressure.

If you've run it hot and used the turbo often - this should also change the fluid level quite a bit when you release that pressure after such a run. It would "deflate" the coolant tank, but also let the pressure equalize, displacing fluid back into the motor

Hi there.. really appreciate ur reply. Last coolant flush is the same time i did changed the fan resistor when overheat prob occur. But its just a normal flushing, drain the old coolant n change with fresh one. For your info the car mileage is about 150k .. 3 month ago i just did the major service which is the wet timing belt including oil pump belt, water pump (oem), a few water hoses, 2 pieces thermostat (with the casing including temp sensor), fresh oil. everything seems fine after the major service. but after a few month later about 2 month .. this overheat prob is rise. The weird things about this prob is, when on rainy days the car is totally fine, no temp rise when idling. but when its come hot sunny day, the overheat issue will come again. (my country is asia so sunny day can reach about 35 to 40 degrees celcius.

 

[Handy Andy]

35 to 40 degrees C? (Coverts to 95F to 104F)

This 150K and turbo - do you know of condition of the turbo - any noises while using it versus more along the lines of the Normally aspirated less throttle action? This leads back to the coolant recovery tank inflation and deflation check for extra pressure from a leaking seal in the cylinder head.

The reasons are many including the Knock sensor(s) if they are working. A lot of spark advance gets engines into trouble - so if the knock is not getting detected at a reasonable level of time - engine damage is the result.

Other factors are the Cylinder head to engine block - possibly take a day to cool down that motor - while at a shop and torque the cylinder head bolts to make sure they are sealing the gasket.

Otherwise - the swapping out of the older hardware has me wondering if you got issues with the water pump and if it's quality is poor or it has failed.

You mention - the "rain" issue of the cooling - ok, that means water is on the radiator fins and coil - so it's cooling off the engine thru evaporation - which only helps as a conversion of temperature to humidity and dewpoint. (Evaporative cooling) Dry air doesn't condense any moisture on the coils and fins to cool them off - so the plugged tubes suggest (only a suggestion) can still apply because there is not enough air passing thru to cool those coils and fins that still circulate the coolant.

Which them tends to lead me back to the newly installed parts - one being the water pump is not pushing fluid as effectively as it first did - so I'd start with what was changed as the suspected parts affecting/causing this condition.