Stock radiator is just awful.

[Fiestig]

Also I see one of you posted the fan doesn't come on unless the AC is running, once I get a tune with that change meaning with custom tunes from Dizzy, Strat, Tune+ etc. do they turn the fan on sooner ?

Hmmm.. If I recall my fan kicks in at 212.6 or so without AC on and no tune.

I went driving in central CA. Drove pretty aggressive to max out my temp and I think the outside max temp I saw was 109. Even stop/go for about 40min with the stock rad I maxed out at 213.8. I couldn't get it to go higher no matter how hard I pushed it with ac on or off.

This is not in anyway to sway someone from getting a mountune rad. It is clearly far superior. I just wanted to do a good test on my super special rainbow kissed unicorn stock radiator.

 

[DAW]

He’s going to need a 2nd bleeder tube as ford calls it. The factory plastic one tends to break when taking the rad off to swap. I’d consider it a must have item for this swap as that piece alone can make the car dead in the water if it’s brokenz

 

[Dpro]

Hmmm.. If I recall my fan kicks in at 212.6 or so without AC on and no tune.

I went driving in central CA. Drove pretty aggressive to max out my temp and I think the outside max temp I saw was 109. Even stop/go for about 40min with the stock rad I maxed out at 213.8. I couldn't get it to go higher no matter how hard I pushed it with ac on or off.

This is not in anyway to sway someone from getting a mountune rad. It is clearly far superior. I just wanted to do a good test on my super special rainbow kissed unicorn stock radiator.

the ECU is programmed from the factory I believe to turn on the AC fan when the temp hits a certain high temp point under normal operation.
Thats how my BMW works as well.

 

[jeff]

One more perspective...I do agree the stock radiator just like the stock FMIC is like a toy. Like toy quality I mean. However unless you live in extreme temps and/or track the car and beat on it for hours at a time, I think the stock radiator is fine. Here in GA it's often over 100 degrees with 90%+ humidity. I've had the OEM radiator for nearly 5 years owning this car with over 300whp and never once seen the coolant temp get into the danger zone. And I'm constantly watching, I monitor it probably more than every 42 seconds. And I'm constantly redlining the car. And it's never come close to overheating.

Again not saying it's great or anything, but this isn't a "must have" mod imho for most of us.

 

[haste]

Let us know how the install goes and what extra parts are needed that didn't come in the box

Everything went smooth, no extra parts needed other than coolant. I already had about 1 1/2 gallons yellow coolant from helping a friend with his install and it was enough. Still about 1/4 gallon left.

Some pics!

On the stands. I was two notches away from the highest setting on my pit bull stands and the rad had plenty of room to come out the bottom. Car is stock ride height.



Intake removed. I took the headlights out too just for extra elbow room. Definitely not necessary but it's so easy to take them out and reinstall.



Cold side charge pipe removed, fan/hood sensor wiring and hood latch cable moved aside. The mountune instructions say to remove the sound symposer from the piping but I didn't find it necessary. It was TIGHT coming out from the bottom but definitely doable. I reinstalled the pipe from the top with the symposer still attached. I wish I had thought ahead about a symposer delete kit...oh well.





Old rad removed. I took it out with the fan shroud attached. Once I figured out the tilt the top out then lift from the bottom to remove it from the mounting holes, it was easy peasy.




All the parts removed during install.





The only part I had to transfer over was the bleed valve. I removed the top two brackets for the fan shroud from the mountune radiator and loosened the bottom brackets for the condenser. I installed the radiator by itself then added the fan shroud to it once I had the radiator secure. Everything went smooooooooth.

Also just got an accessport from mountune at the same time with stage 3 93 tune loaded on it. I still have the stock intercooler but it's good enough for now. This is my wife's car at the moment so it doesn't get pushed hard. Car feels good.

 

[M-Sport fan]

Does anyone make an upgraded, higher CFM fan/motor which fits into the factory shroud mounting points, and fully integrates/interfaces with the fan module?

 

[Capri to ST]

[QUOTE="Intuit, post: 420730, member: 4881"
I wonder whether engineers *purposefully* made these car engines run on the hotter side, just to cleanup the cylinders? ...
...
Unless it's actually or nearly overheating, consider the possibility that maybe the engineers wanted to run these on the hotter side; and changing that may have unintended consequences, way down the road.[/QUOTE]
I wondered about that too. Taking that a step further I remember reading an article about modern engine temperatures written by the tech writer for the BMW magazine. He said that engineers manipulate engine temperatures for a variety of reasons, and because of that modern temperature gauges often aren't too sensitive, and just tend to read in the middle as long as the temperature is within an acceptable range so people don't worry when seeing the fluctuations.
Many of the owners on here have AP's and thus are seeing more exact temperatures, and I wonder if that is making people worry about something that doesn't need to be worried about? Of course some people have actual overheating, but some people are getting worried by high temperatures, which as Intuit said, may be by design. I'm not saying this is definitely the case, just that it's something to think about.

 

[Dpro]

[QUOTE="Intuit, post: 420730, member: 4881"
I wonder whether engineers *purposefully* made these car engines run on the hotter side, just to cleanup the cylinders? ...
...
Unless it's actually or nearly overheating, consider the possibility that maybe the engineers wanted to run these on the hotter side; and changing that may have unintended consequences, way down the road.

This may be true be honestly doing a canyon run at 2 in the afternoon with AC, ( forgot it was on, it was high 90’s at the bottom of the canyon) on my car hit the flashing dash temp warning freakout mode in 85-90 degree weather near the top of Canyon here in SoCal . After that experience I realized if one wants to drive the car spiritedly in dry hot air they can expect it to freakout and go limp. I installed my Mountune rad shortly after that and have not looked back.
Depending on where one lives MMV.

 

[jayrod1980]

I recall Adam from Tune Plus telling me he optimizes cooling, so I’m guessing that means he somehow programs the fans to come on more aggressively.

I will say, moving from the DHM plus crash bar to the Bravo Alpha, my average coolant temps are higher. With the DHM and Mountune the car was almost always stuck at 184-187F when warmed up (thermostat seemed to kick on when warming up between 192-200F). With the BA I almost always hover between 191-197F unless I’m going up a steep grade or get into extended time at positive boost pressure. I think it’s mostly because the IC is literally jammed against the Plastic radiator bracket and just inside the stock crash bar. The DHM tubular crash bar sticks out farther and there’s more space between the radiator and IC due to the mounting straps on the crash bar. I actually got up to 222F with the BA doing a long incline up a mountain at 100F+ outside temps. I’m seriously considering reinstalling the DHM if I can find a welder here for the crack in my intercooler. If I do, I’ll do a much better job at making sure I have a gap between my hard pipes and the end tanks, as I’m sure constant contact between the two on my cold side IC pipe caused the crack in my IC. How does one go about finding a skilled aluminum welder?

 

[jmrtsus]

One more perspective...I do agree the stock radiator just like the stock FMIC is like a toy. Like toy quality I mean. However unless you live in extreme temps and/or track the car and beat on it for hours at a time, I think the stock radiator is fine. Here in GA it's often over 100 degrees with 90%+ humidity. I've had the OEM radiator for nearly 5 years owning this car with over 300whp and never once seen the coolant temp get into the danger zone. And I'm constantly watching, I monitor it probably more than every 42 seconds. And I'm constantly redlining the car. And it's never come close to overheating.

Again not saying it's great or anything, but this isn't a "must have" mod imho for most of us.

I agree, for 4 years mine was fine in the South East. But a trip to record high temp South Western states showed they have a situation where improvements are needed. Since I have family there and will be returning I have a Mountune radiator coming tomorrow. My daughters ST in Indiana has also never had a problem with overheating. Location matters, mods matter,usage matters. If you have a need to upgrade do it. If not save the money, it has always been that way. The day my FiST was pulled over to cool down on I 70 W so was 3 other cars and one truck on a day of record heat in the area.....none were FiSTs.

 

[bombo107]

He’s going to need a 2nd bleeder tube as ford calls it. The factory plastic one tends to break when taking the rad off to swap. I’d consider it a must have item for this swap as that piece alone can make the car dead in the water if it’s brokenz

You don't happen to know this part number by any chance do you? I'm going to be installing my radiator within the next week or so and want to be prepared as possible.

 

[haste]

You don't happen to know this part number by any chance do you? I'm going to be installing my radiator within the next week or so and want to be prepared as possible.

Just push on the release at the bottom to spread out the locking tabs then gently wiggle it out. I've done three so far without a problem. One car was five years old and has 80k miles on it.

 

[haste]

Double post...ignore.

 

[bombo107]

Just push on the release at the bottom to spread out the locking tabs then gently wiggle it out. I've done three so far without a problem. One car was five years old and has 80k miles on it.

Okay will do and thank you for the advice.

 

[Philld_with_donuts]

[QUOTE="Intuit, post: 420730, member: 4881"
I wonder whether engineers *purposefully* made these car engines run on the hotter side, just to cleanup the cylinders? ...
...
Unless it's actually or nearly overheating, consider the possibility that maybe the engineers wanted to run these on the hotter side; and changing that may have unintended consequences, way down the road.

I think these coolant temps were 100% by design. And the reality is, not all cars are designed with an overwhelming "fudge factor" to allow for modifications after the point of sale. Cooling a direct injected 4-cylinder turbo engine is one of the most difficult engines to cool. The heat rejection requirements are generally higher than larger displacement V8's, or even large displacement forced induction engines. High power / displacement ratios lead to crazy high heat rejection requirements, and small blocks lead to small coolant passages the waterpump has to fight through.

But a couple reasons that Engineers at Ford may have decided to run a bit hotter could be:

- higher coolant temp results in higher oil temp. Hotter oil results in less viscous drag, leading to better fuel economy, better emissions, and higher rated power.

- higher coolant temp results in a higher temperature engine block, leading to higher temperatures on the cylinder walls. A cylinder wall with more thermal inertia will be more resilient to LSPI (Low-speed pre-ignition), which is a phenomenon that is markedly worse in 4-cylinder, turbo, DI engines and no one has a complete grasp on why or how to solve it yet in the industry.

Aside:
An unpopular opinion I have is the radiator is not the problem with the stock cooling systems design, it's actually the thermostat.
The thermostat start-to-open temperature controls the book ends for how hot the vehicle will run. The radiator controls the runaway once the thermostat opens. Our cars coolant temp (stock) doesn't seem to run away, they just run hot. That's the thermostats fault.

...but I run a Mishimoto radiator, so what do I know. lol

 

[powermatt]

Aside:
An unpopular opinion I have is the radiator is not the problem with the stock cooling systems design, it's actually the thermostat.
The thermostat start-to-open temperature controls the book ends for how hot the vehicle will run. The radiator controls the runaway once the thermostat opens. Our cars coolant temp (stock) doesn't seem to run away, they just run hot. That's the thermostats fault.

...but I run a Mishimoto radiator, so what do I know. lol

I don't think thermal runaway has ever really been the issue. When my '15 tried to overheat going up an incline, it wasn't running away, it just was unable to cope with 85+ F ambient temps, relatively low speeds (~30-40 mph) and being constantly spooled. Within 15 minutes of pulling over and letting it idle, it was back down in normal temperatures. It was just simply that the heat being generated in that specific scenario exceeded the cooling system's capacity to shed heat.

 

[New_Daily]

Figure I'll add my experience thus far to add to the collective (anecdotal) data.

I got my car in Feb so I only daily drove it 3-4 weeks before covid and switching to work from home. Also, I didn't have my AP right away so don't know what the actual temp was for the first bit of driving it.

It wasn't really hot here in the time that I had my AP and before my Mountune rad, but the highest I generally saw was 197 or so. After installing, its about the same at highway speeds. When I have a downhill it will get down into the 180's, then back to 195-197 freeway cruising speed on flat.

Monday was the hottest I have driven it in at about 100 ambient, then sat it idling in the heat with the AC on. It stayed nice and true at 197-198 even as I saw the post IC intake temp get to 136 which I'd never seen before.

The one thing I have seen (which I posted about in another thread) was a 35-40mph uphill leading to the freeway, then getting on the frewway it was still uphill for a mile or so. It was about 85-90 that day and climbing the freeway at freeway speeds it got to 208. That bothered me since it wasn't all that hot out and I was at freeway speed. I have since purged at the purge valve again (didn't see any more air come out, just a steady coolant stream) and lowered the coolant level a little as I was above the max shown on the expansion tank.

I have not repeated that same driving scenario yet, but it seems to be good temp wise.

So for me, it seems any hot day standstill traffic I sit in I will be fine, but those inclines jump the temp up.

 

[Poofies]

I picked up an 18 two days and on the first day of driving in socal (110) I got to 6/8 bars and rising on stock car with stock tune with the ac at full blast. I turned of the air and turned on the heater and the temp went back to 4/8 bars quickly. I researched the car before so went home and ordered a mountune radiator. Kind of disappointing but I’ve already ordered a lot of parts so upgrading the rad was probably inevitable. At least it was on sale.

 

[Dpro]

I don't think thermal runaway has ever really been the issue. When my '15 tried to overheat going up an incline, it wasn't running away, it just was unable to cope with 85+ F ambient temps, relatively low speeds (~30-40 mph) and being constantly spooled. Within 15 minutes of pulling over and letting it idle, it was back down in normal temperatures. It was just simply that the heat being generated in that specific scenario exceeded the cooling system's capacity to shed heat.

Exactly. This cooling system was not designed to pushed in those kinds of temps. Remember car was designed off a base economy car in Germany which is basically Northern Europe and on a much higher latitude than most of the continental United States.

Temps in parts of the U.S, are drastically different and the funny thing is no ordinary Fiestas do not overheat. You know why cause there is plenty of from air coming in because no one blocked off the lower portion with a fricken intercooler lol. How do you cut down cool airflow to a radiator put an obstruction that take the air and heats it up before passing it on lol.

Not only that but I have not looked but I would not be a bit surprised if our stock radiator is the same damn thing on a Standard Fiesta.

So basically that leads back to the fact that the car was never engineered to have a intercooler up front with a stock radiator.

Now given the temps in Northern Europe most of the time and the UK its not a bit surprising that they did not stop to think about it. It worked over there quite possibly.
So ya I call BS on the concept of the high temps by design theory.
No design theory just cause and effect . lol

 

[Capri to ST]

I checked a while back because reading this thread got me curious and our radiator did have a different part number than the radiator for a base Fiesta.