Pros and Cons of the Fiesta's Radiators

[SrsBsns]

I did a write up on the Mountune install. It's very straightforward. Here it is: https://www.fiestastforum.com/threads/thoughts-from-mountune-radiator-install.23121/#post-408890

I got the Mountune on sale and I have to say that it's one of the best purchases I've made for the FiST.

Temps are always consistent now even when doing some spirited driving, uphill, with AC, etc... I rarely see temps climb over 200'. I am running about 60/40 with a couple bottles of water wetter.

 

[FiestaSTdude]

I did a write up on the Mountune install. It's very straightforward. Here it is: https://www.fiestastforum.com/threads/thoughts-from-mountune-radiator-install.23121/#post-408890

I got the Mountune on sale and I have to say that it's one of the best purchases I've made for the FiST.

Temps are always consistent now even when doing some spirited driving, uphill, with AC, etc... I rarely see temps climb over 200'. I am running about 60/40 with a couple bottles of water wetter.

Awesome, I will definitely be referencing that write up in the future.
Potentially stupid question: what is water wetter? I keep hearing people referring to adding it. What does it do?

 

[XR650R]

Potentially stupid question: what is water wetter? I keep hearing people referring to adding it. What does it do?

Genuine questions are not stupid. I used it in my water-cooled dirt bike. SoCal gets pretty hot.
Never used it in a car. My cars don't overheat.
This is Redline, but everybody sells it. https://www.redlineoil.com/waterwetter

 

[M-Sport fan]

There are about 30+ different variations on that stuff from other companies as well.

My personal fave being this one; ttps://www.napaonline.com/en/p/BK_7652972?cid=paidsearch_shopping_dcoe_google&campaign=GSC-Chemicals

 

[SrsBsns]

Awesome, I will definitely be referencing that write up in the future.
Potentially stupid question: what is water wetter? I keep hearing people referring to adding it. What does it do?

I'm not sure how effective it really is, but I figured it wouldn't hurt. It's supposed to help maximize the cooling ability of the water/coolant mix.

 

[dhminer]

Just bought the Mountune radiator from whoosh! Now I need to flush my coolant and swap in the new radiator and hopefully say bye bye to all my cooling isssues.

Just a word of advice, it takes way longer but is easier to take off the crash bar and replace the radiator that way. Getting the radiator in from the underside was a curse word filled activity.

 

[SteveS]

Potentially stupid question: what is water wetter? I keep hearing people referring to adding it. What does it do?

Water wetter is supposed to decrease the surface tension of water, making it better able to make contact with the interior surfaces of the radiator and engine, thereby making it easier to transfer heat out of the engine and to the air. This is supposed to work by reducing bubbling of the water around the hot metal.

It is claimed to reduce water temperature by as much as 10 degrees. There are some wilder claims made, but the temperature is the main one.

It does not work in the presence of glycols, so if you are going to use it you have to fully flush all antifreeze out of the system, and fill with only distilled water and water wetter. In fact many of the manufacturers of water wetter say that it will not improve temperatures if mixed with antifreeze. It is not as slippery as glycols when spilled on the ground which is why some racing associations require it or just plain water and outlaw antifreeze.

Water wetter does not change the freezing point of water, so if the car is subject to sub-freezing temperatures it will not protect your engine block from freezing.

There are reports that using water wetter did not prevent corrosion (rust) in the engine, but most of the products say they have corrosion inhibitors.

 

[Alkoran]

Just a word of advice, it takes way longer but is easier to take off the crash bar and replace the radiator that way. Getting the radiator in from the underside was a curse word filled activity.

From the underside? When I did mine, I took took off the old and installed the new all from above. And I didn't took much of anything else off, not even the bumper. Didn't had any problem either, it went well.

 

[esp_martin]

I have the Mountune radiator and have family in Charlotte, NC. In mid August while pulling the steepest hills on I-81 the engine temperature never waivers from showing 4 bars. I will also note that after installing the Mountune 3 pass radiator my fuel economy increased by 4 mpg in the city and on the highway. Turns out that the 195 degree radiator supplied with the car is the IDEAL operating temperature for this engine. BTW, winter mileage in the city is not as good, these cars drink gasoline when the engine is cold and that larger radiator slows down the engine getting up to optimum temperature. As a result winter mileage is off by about 5 mpg versus summer city driving.

Tip for the Mountune radiator and this was learned from real world experience. The Mountune radiator is thicker than the factory radiator and as a result the fan shroud is moved closer to the engine. After installing the Mountune radiator look very closely at that fan shroud and make sure that it's not rubbing on any hoses anywhere. If you allow hte shroud to rub on a coolant hose at about 30,000 miles you will have a coolant leak and you'll also find the hose you need is NOT stocked at a Ford dealership. BTW, I used a bicycle tire patch and electrical tape to effect an repair while I waited for the new hose to arrive.

to be fair, there are many other reasons why a vehicle gets worse gas mileage in the winter months (winter mix gasoline not as energy dense being one of them)
Fuel Economy in Cold Weather

if you live in a cold enough climate where this is a big issue there is always an engine block heater too if you're thinking of going big boy radiator and it's your daily

 

[FiestaSTdude]

Just a word of advice, it takes way longer but is easier to take off the crash bar and replace the radiator that way. Getting the radiator in from the underside was a curse word filled activity.

Thanks, I need to replace my crash bar anyway

 

[dhminer]

Thanks, I need to replace my crash bar anyway

Hit me up if you need another set of hands

 

[M-Sport fan]

Water wetter is supposed to decrease the surface tension of water, making it better able to make contact with the interior surfaces of the radiator and engine, thereby making it easier to transfer heat out of the engine and to the air. This is supposed to work by reducing bubbling of the water around the hot metal.

It is claimed to reduce water temperature by as much as 10 degrees. There are some wilder claims made, but the temperature is the main one.

It does not work in the presence of glycols, so if you are going to use it you have to fully flush all antifreeze out of the system, and fill with only distilled water and water wetter. In fact many of the manufacturers of water wetter say that it will not improve temperatures if mixed with antifreeze. It is not as slippery as glycols when spilled on the ground which is why some racing associations require it or just plain water and outlaw antifreeze.

Water wetter does not change the freezing point of water, so if the car is subject to sub-freezing temperatures it will not protect your engine block from freezing.

There are reports that using water wetter did not prevent corrosion (rust) in the engine, but most of the products say they have corrosion inhibitors.

Plus; even though some naysay that it does actually 'gum up', and form a slime like sludge substance in the presence of any Dex Cool type coolant (which our old orange Motorcraft WAS, but I am not sure about the new green-yellow compound), I actually DID experience just that happening in my Z28.

Others claim that this only happens/happened in the presence of air in the system, but my cooling system was fully bled, and totally airless.

This only happened (to me at least) when using the gasoline engine designated Red Line RED Water Wetter, when I used the BLUE diesel designated stuff, it was just fine.

It NEVER happened when using the Lube Gard stuff above.

 

[DarkFiST20]

I would grab the koyo. I think in the reviews on whooshs site it says the shroud fitting was "fiddly". A dude on youtube did a video on his and loved the results and didnt mention any fitment issues.

I have the Koyo rad. No fitment issues with the radiator itself or the shroud. Biggest issue was fitting my CPE Cold side charge pipe. It's a thicker radiator and a tighter fit.

 

[FiestaSTdude]

Does anyone know how much coolant it takes to refill the system after I drain it to change the radiator? I have two bottles of the motorcraft coolant and I’m wondering if I should get another one

 

[Alkoran]

Owner manual states 2.1 gallons or 8 liters. I'd use the 2 jugs you have and top it off with distilled water.

 

[Dpro]

Just a word of advice, it takes way longer but is easier to take off the crash bar and replace the radiator that way. Getting the radiator in from the underside was a curse word filled activity.

This is how we did mine . I documented it in my build thread it actually made the install easy. I would also say if you want to fit a cold side charge pipe this is the time to do it as well. As after the aftermarket radiator is in it becomes a pita.

 

[M-Sport fan]

Owner manual states 2.1 gallons or 8 liters. I'd use the 2 jugs you have and top it off with distilled water.

As long as the coolant he has is the 50/50 pre-diluted stuff, and NOT the 100% coolant concentrated fluid.

 

[Capri to ST]

Does anyone know how much coolant it takes to refill the system after I drain it to change the radiator? I have two bottles of the motorcraft coolant and I’m wondering if I should get another one

The owner's manual for my '16 says the capacity is 6.1 qt, so you should be fine with two gallons, although I don't know how much more capacity if any your radiator of choice will have.

 

[Alkoran]

As long as the coolant he has is the 50/50 pre-diluted stuff, and NOT the 100% coolant concentrated fluid.

Of course, I assumed he knew that!

The owner's manual for my '16 says the capacity is 6.1 qt, so you should be fine with two gallons, although I don't know how much more capacity if any your radiator of choice will have.

Weird that they changed that capacity from years to years, mine being a 2018.

 

[Capri to ST]

Weird that they changed that capacity from years to years, mine being a 2018.

There's been some debate on here about whether they did increase the capacity, or whether that larger number is just a typo in the newer owner's manual. I don't believe the radiator capacity was changed in later years, and that is backed up by the fact that the 2016 and 2018 radiators have the same part number, which I just double checked.