Engine Overheating

[Dpro]

Is the Mountune radiator actually functional at reducing temps, or is just mod bling. I'm moving to Arizona next week, and I don't care about aftermarket bling. I need to fix this overheating issue or replace the car. I love my little ST, but this overheating issue is inexcusable.

No its not mod blind I was driving around in 100 degree heat today here in LA with my air rocking 60 degrees with some boosting and my temp was 191. Thats with a Mountune Rad and the later Bar and Plate Mountune intercooler.

Now I would say about the Mountune rad, buy it now while its on sale and in stock for $475.
On ther intercooler front there are a fair amount of choices I have a Mountune because I got it for $365 new when there were not as many choices for less. Now I would say go Whoosh.

 

[vmaxbaby]

So Mountune is the recommend Radiator of choice over Mishimoto. The price difference is nothing but I want one that fits like OEM, I don't have to rig anything to get it to work, and I don't have to tear the front of the car apart to install? So which model is that ?

 

[Dpro]

So Mountune is the recommend Radiator of choice over Mishimoto. The price difference is nothing but I want one that fits like OEM, I don't have to rig anything to get it to work, and I don't have to tear the front of the car apart to install? So which model is that ?

Go with the Mountune.

 

[powermatt]

So Mountune is the recommend Radiator of choice over Mishimoto. The price difference is nothing but I want one that fits like OEM, I don't have to rig anything to get it to work, and I don't have to tear the front of the car apart to install? So which model is that ?

The Mishimoto does fit, but barely. And you do have to remove the crash beam to install it.

 

[CaptainCheesy]

I saw temps that high almost daily while commuting and getting stuck in traffic.
Mountune radiator has me running under 190 all day now. Can't recommend it enough.

That's the triple pass one, right?

 

[SrsBsns]

That's the triple pass one, right?

That's right. The Mountune is a triple pass.

 

[BillSchm]

I've had a Mountune radiator since mid-summer. Car is a 2019 ST.

The stock radiator is likely fine for all other models of Fiesta, but not up to the ST version.

I started overheating one day coming north out of Phoenix, climbing from 1500 ft to 5000 ft at 106 degree temp outside. "Ding, ding, ding" it was saying. I limped off and on, pulling over to drop the temp gauge, then drive another 500 ft. till I got off the hill. Ordered the Mountune the next day and have NEVER had a problem since. It's been over 110 many days and the hill climb would have been a killer without the Mountune radiator. Love it!!

 

[CaptainCheesy]

I would highly recommend not going to a 160°f thermostat. Folks on here will bite your head off over the 160°f vs 180°f vs stock thermostat. I did the mountune radiator install and was going to do the motorcraft 180°f thermostat next. The mountune radiator completely solved the overheating issue on my end. Even with the days hot as hell, I rarely if ever see anything above 199.9 (with stock thermostat) after the mountune radiator upgrade. The thermostat is a step further than what would normally be needed but that is my $0.02. Hope you're able to sort this out, that is a pain to deal with, concerning, and frustrating.

So I've swapped my radiator from factory to the Mountune, and had a big issue of overheating. I did some bleeding, fixed that right away. I have not paid attention to temps in the hot summer, but I don't think I've seen above 215F at most. This upcoming summer I will be committing to a full coolant flush and swap though. Possible thermostat swap as well. I'll keep you guys posted as it all develops.

 

[Bull Run]

So I've swapped my radiator from factory to the Mountune, and had a big issue of overheating. I did some bleeding, fixed that right away. I have not paid attention to temps in the hot summer, but I don't think I've seen above 215F at most. This upcoming summer I will be committing to a full coolant flush and swap though. Possible thermostat swap as well. I'll keep you guys posted as it all develops.

Thanks for the update. I bought my car in last August and didn't have any overheating issues during near 120F ambient temp days, but I mostly drive on flat roads.

 

[iammacey]

Thanks for the update. I bought my car in last August and didn't have any overheating issues during near 120F ambient temp days, but I mostly drive on flat roads.

It's definitely heat generated by the turbo. Prior to upgrading my radiator I could do one or two hit laps at the track and push it to near limp mode. I could back off, stay out of the boost, and it would cool back down.

I did have it overheat on 100 degree day sitting in stop/go traffic with OE radiator. But flat roads, not getting the brakes up to high temps, staying out of boost you should be good.

 

[XR650R]

It's definitely heat generated by the turbo. Prior to upgrading my radiator I could do one or two hit laps at the track and push it to near limp mode. I could back off, stay out of the boost, and it would cool back down.

I did have it overheat on 100 degree day sitting in stop/go traffic with OE radiator. But flat roads, not getting the brakes up to high temps, staying out of boost you should be good.

I live in the NE corner of the US. We don't see 100 degree days very often (yet!). I've never gone over 4 bars on the dash in the summer, regardless of how I'm driving.

I kinda see it like the RMM: Ford wanted to keep the car cheap, and let the aftermarket fix the issues. The aftermarket is so good, that enthusiasts have 3 or so radiators to choose from. If I lived in Tucson, or anywhere where heat gets regularly up to 100+, a mountune radiator would be just as mandatory as a better RMM and a shift kit.

 

[Bull Run]

It's definitely heat generated by the turbo. Prior to upgrading my radiator I could do one or two hit laps at the track and push it to near limp mode. I could back off, stay out of the boost, and it would cool back down.

I did have it overheat on 100 degree day sitting in stop/go traffic with OE radiator. But flat roads, not getting the brakes up to high temps, staying out of boost you should be good.

I agree as I also have a Mustang Ecoboost. It's a Performance Pack with a slightly larger radiator than the non-PP model, but the coolant temp still creeped up during a long mountain climb under boost (above normal but nowhere close to overheating).

I haven't had any issues with stop-and-go traffic during hot days, but I'm still teleworking so I haven't been driving much recently. I'll look into getting a Mountune or Whoosh upgrade during the next sale (unless I experience overheating sooner).

 

[CaptainCheesy]

I'm FBO, minus any upgrades to fuel, engine, turbo, or tranny. I've done pulls with E30 during roughly 80-85F days with the Mountune radiator and stock thermostat, and it's done me quite well. I think I would benefit much more to install an oil cooler and perhaps a heat shroud for the hot side of the turbo, and exhaust wrap for my catless DP. I feel it would control the heat back there a lot better.

 

[jmrtsus]

My MP-215 had never overheated in the East and SE for almost 5 years. But a summer trip to the mountains and deserts in the Southwest made Fi-fi very unhappy so she has a Mountune Radiator now and was happy out there last summer. I would say in the SW quadrant of the USA it is a requirement to upgrade. I think the Mountune was a high quality part as expected, and not cheap as expected.

 

[CaptainCheesy]

My MP-215 had never overheated in the East and SE for almost 5 years. But a summer trip to the mountains and deserts in the Southwest made Fi-fi very unhappy so she has a Mountune Radiator now and was happy out there last summer. I would say in the SW quadrant of the USA it is a requirement to upgrade. I think the Mountune was a high quality part as expected, and not cheap as expected.

Eventually here soon, I want to complete a coolant flush and swap from standard coolant and go to Evan's Performance Waterless coolant. It's glycol based, eliminates all problems associated with water and whatnot. Also has a much higher boil-off temperature too, I think it's closer to 250F if I remember right.

 

[CaptainCheesy]

I live in the NE corner of the US. We don't see 100 degree days very often (yet!). I've never gone over 4 bars on the dash in the summer, regardless of how I'm driving.

I also agree, being in MD we don't get much past 95/100F.. but I've been all over the country in Sub Zero, so. Once I finish my coolant flush & swap, I'll see what temps I get out of all that. Might be worthwhile, not just for temperature management purposes and engine preservation.

For those that are curious..

What is Waterless Coolant / Waterless Coolant Benefits

 

[iammacey]

Eventually here soon, I want to complete a coolant flush and swap from standard coolant and go to Evan's Performance Waterless coolant. It's glycol based, eliminates all problems associated with water and whatnot. Also has a much higher boil-off temperature too, I think it's closer to 250F if I remember right.

I'll be very curious to hear results of this. I appreciate you sharing and also including a link in your additional post.

Higher heat at the cylinder heads and HP reduction would be my top two concerns, so I'm extremely interested in what you find if, and when, you do this.

 

[rallytaff]

Oh, I saw Mishimoto and just automatically read radiator for some reason. Reading is hard...

It's well documented that the stock cooling system on these cars are bad. The stock radiator is terrible.

Hate to disagree with you here. I had a Stage 3 tune from FSWerks for 7yrs with a stock radiator and COBB intercooler and ran in all temps with NO problems.

 

[Dpro]

Hate to disagree with you here. I had a Stage 3 tune from FSWerks for 7yrs with a stock radiator and COBB intercooler and ran in all temps with NO problems.

Have to disagree with you here all it took was one route check run in the hills with air on in 85 degree temps and it was hello flashing dashlights and limp mode.

Has nothing to do with tune either as I was running the same tune that you are when that happened. Ya it was years back now.

Now granted I forget I had my air on when I started because it was 90 plus at the bottom . Though I can honestly say stuck in Socal traffic in the summer with air on will most likely cause what I experienced.

Lots of people have reported it sure there are outliers but most people report and it is a fact the stock radiator on our cars is a wimpy plastic end tank piece of crap.

Oh and ya I think I did mention how spectacular plastic end tanks can be exploding at speed earlier. It can and does happen. Its just pure easy common sense and piece of mind. Replace stock radiator with aluminum triple pass never look back or think about to again.
Its really excellent preventive maintenance.