Overheating Issues for Fiesta ST

[one.slow.fist]

Haven't tried another dealer yet but my experience from this dealer has really strayed me away from bringing it to another dealer.

 

[one.slow.fist]

Thanks for the post. I'm satisfied with my intercooler. It shows really good charge temps compared to the stock one but I'm sure anything other than stock will do that. I'm looking into other alternatives to radiators as I think that's my problem. The techs at ford didn't even want to pressure test the cooling system because they "couldn't get it to overheat" but when I checked the mileage, It didn't show them driving the car around at all.

 

[jwolfe]

Thanks for the post. I'm satisfied with my intercooler. It shows really good charge temps compared to the stock one but I'm sure anything other than stock will do that. I'm looking into other alternatives to radiators as I think that's my problem. The techs at ford didn't even want to pressure test the cooling system because they "couldn't get it to overheat" but when I checked the mileage, It didn't show them driving the car around at all.

This is why I am going to just upgrade. I was told that it's not abnormal for newer cars to have engines that run over 200C .

 

[M-Sport fan]

This is why I am going to just upgrade. I was told that it's not abnormal for newer cars to have engines that run over 200C .

You mean 200* F coolant temps (actually they run up to 220*F for emissions/CAFE reasons, with higher pressure cooling systems), NOT 200* C, which is close to 400* F!!

 

[jwolfe]

You mean 200* F coolant temps (actually they run up to 220*F for emissions/CAFE reasons, with higher pressure cooling systems), NOT 200* C, which is close to 400* F!!

Yes sorry, 200F 200C and you can grill on it.

 

[alexrex20]

Just get the Mountune. In 100F weather and stop and go traffic, my 2017 can get up to 219F. I am saving up for the Mountune radiator.

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[one.slow.fist]

Would you happen to know if the mountune radiator uses the stock fan shroud or would I have to order a seperate one? I know mishimoto needs you to order their fan shroud as well. I'm hoping to hear some news on people that has the radiator on their cars and if its worth it for me.

 

[one.slow.fist]

Disregard my last post about the fan shroud... I read the full description on mountunes site... lol but I may save up and do the same

 

[DeadDred]

Yesterday it was 34C (93F) and was driving in town and came up to a hill that is about a 1KM long. Was driving up at about 100km/h and temps climbed up to last bar (no over heat warning signs). Luckily got to the top and on a flat spot at a stop sign as was in heavy traffic and couldn't pull over. So this is about the 6+ time since I've had it for two months. Most times it up going up hill but twice was on flat with AC running on a 28-30C day.

I got next week off so will take it in and report back.

 

[KentRatke]

The Mountune rad has solved all my issues. Cannot recommend enough

 

[KentRatke]

Yesterday it was 34C (93F) and was driving in town and came up to a hill that is about a 1KM long. Was driving up at about 100km/h and temps climbed up to last bar (no over heat warning signs). Luckily got to the top and on a flat spot at a stop sign as was in heavy traffic and couldn't pull over. So this is about the 6+ time since I've had it for two months. Most times it up going up hill but twice was on flat with AC running on a 28-30C day.

I got next week off so will take it in and report back.

Mine was almost always on hills. If you're interested, get the Mountune Rad upgrade, it makes such a stunning difference in cooling. Are you fully stock?

 

[DeadDred]

The Mountune rad has solved all my issues. Cannot recommend enough

I'd consider that only an option if the warranty was out. Still got 40K on warranty plus 160K with extra warranty. Will see what the dealer says next week plus the in dash display is fucked on most warm days. I plan on keeping the car for at least 5 years so will be getting as much warranty stuff done as I can.

 

[DeadDred]

Mine was almost always on hills. If you're interested, get the Mountune Rad upgrade, it makes such a stunning difference in cooling. Are you fully stock?

Yes fully stock atm but have a Whoosh IC coming, hopefully in next week. I was planning on COBB/Stratified tune but will wait till I some of the issues looked at, don't want to be arguing with the deal for possible warranty voids because I got a tune.

 

[shawn36]

Thermostat replacement and/or hood louvers?

Has anyone tried replacing the thermostat on an overheating FiST? It's only a $47 part (Part Number: 8575(RH-223)), though installation looks a bit involved.

My 2016 FiST with 20,000 miles has come close to overheating on three occasions, each time requiring that I turn on the heater to get temps back down. Each time the ambient air temps were 95 or higher and I had the A/C on. Twice I was going uphill on winding roads and once I was in stop-and-go traffic after hours of 80 mph highway driving. The general problem seems to be that once coolant temps get above 220 or so, the car can't keep itself cool without lots of airflow, no matter how how much the radiator fan runs.

My FiST isn't stock. I installed a Mishimoto J-line intercooler, which is thicker and hangs lower than stock. I have a Mountune tune, which removes restrictions on boost in 1st and 2nd and allows boost up to 24 psi. I have a Boomba Racing CCV catch can and a Mishimoto PCV catch can, though I relocated the later to the passenger-side strut tower to eliminate the possibility that it was restricting airflow.

My oil temps (according to the Accessport) can reach 250 when highway driving in 100 degree temps. I run Mobile 1 5w-20. I added an oil pressure gauge that necessitated installing a sandwich plate between the oil filter and engine. This prevents one of the radiator shroud flaps from opening fully.

On my car, the fitment of the A/C condenser, radiator, and radiator shroud assembly is poor, i.e., there are lots of air gaps. Ford saw fit to "seal" the gap on the passenger side between the condenser and the radiator with, basically, gray foam weather stripping, which fell off. I made an aluminum bracket to re-seal it.

It's possible that my intercooler is to blame for the overheating -- I've tested the car without the tune and the overheating persists -- but, even though the intercooler is larger than stock, there are no airflow restrictions above the crashbeam. When I installed the intercooler I retained the radiator air deflectors (Part Numbers: 8310A, 8310C, 8310E, 8327A, 8327B), but airflow is a dark art, so perhaps I fouled something.

A new radiator is tempting, though it feels like that would sort of be blindly throwing money at the problem. I like that the Mishimoto does away with the stock fan/shroud assembly, given the bad fitment on my car. I would happily take a 2-inch hole saw to my car to make low-fi hood louvers, if I were confident that would help.

 

[Quisp]

I don't think a thermostat is going to cure overheating. It's wide open before that occurs. Both mountune and Mishimoto radiators have been proven effective .

 

[MoxBoost]

I went with a mountune radiator. My coolant temps used to reach 240 on an average day. I did a thermostat after 15k which helped in the beginning but temps slowly climbed back up. I replaced the radiator which got the engine temps under control. I need an oil cooler now to get the oil temp under control becuase that still hits 220+ on average.

Most of these small engine vehicles seem to have similar issues of running hot. At work most of our dyno engines run around 230 all day long.


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[shawn36]

I need an oil cooler now to get the oil temp under control becuase that still hits 220+ on average.

What would you consider to be acceptable oil temps? Obviously, synthetic oils will tolerate temperatures greatly in excess of what our engines can stand, so the worry isn't breaking down the oil. As many have noted, with coolant, once temps reach 236+, the FiST starts thinking about protecting itself. Does something similar happen with oil temps? According to the manual, "the PCM (Powertrain control module) uses an oil algorithm to infer actual temperature based on input from the engine temperature sensor." I was assuming that, once coolant temps were under control, oil temps would take care of themselves since they are cooled via the same system. (But I'm not a mechanic or engineer.)

 

[GAbOS]

220+ is where you want oil temps to be at. Water starts to boil out of it at 220. You don't want it cooler than that when pushing a car hard in track conditions. Oil is not water folks.

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[GAbOS]

'conventional' oil doesn't start breaking down until 280ish.

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[MoxBoost]

What would you consider to be acceptable oil temps? Obviously, synthetic oils will tolerate temperatures greatly in excess of what our engines can stand, so the worry isn't breaking down the oil. As many have noted, with coolant, once temps reach 236+, the FiST starts thinking about protecting itself. Does something similar happen with oil temps? According to the manual, "the PCM (Powertrain control module) uses an oil algorithm to infer actual temperature based on input from the engine temperature sensor." I was assuming that, once coolant temps were under control, oil temps would take care of themselves since they are cooled via the same system. (But I'm not a mechanic or engineer.)

Operation conditions inside the engine play a major influence in the service and severity of the lubricating oil. Engine oil plays a critical role in cooling by extracting heat from the engine, oil cooler and dissipating it through the walls by radiation dispersion into engine coolant. The importance of chemical stability here is the ability of the oil to resist break down and not form deposits and oxidize to early which will interfere with the heat transfer and cause premature wear on engine components. Some components will still wear down like the engine cylinder rings because of unavoidable metal to metal contact but those other components are in an unnecessary state because of engine oil breakdown. Now my need for oil will be different than your because I race my car most weekends. In doing so I want an oil cooler so while I'm out on my 20minute session my oil will not break down as fast.


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