Coolant Temps

[2Noob4U]

So it appears that the radiator isn't keeping things cool. Has anyone changed out the thermostat to a 180* or lower to see if the radiator keeps up? I know with past vehicles that are driven in colder climates having anything colder than 180 make defrosting the windows kinda crappy.

 

[Erick_V]

So it appears that the radiator isn't keeping things cool. Has anyone changed out the thermostat to a 180* or lower to see if the radiator keeps up? I know with past vehicles that are driven in colder climates having anything colder than 180 make defrosting the windows kinda crappy.

Ron at whoosh motorsports just came out with a radiator that's $375 shipped, sold out super fast but it says on his website he's resuming orders next month. Between that and the 180 degree thermostat you (likely) won't overheat on the street ever again. I live in South Texas and we get days where its over 100 degrees outside. I don't think I've cracked over 200 degrees street driving on my Mountune Radiator and on the OEM thermostat. If this was an option when I was in the market for one I would have given him a shot:

https://whoosh-motorsports.myshopif...ce-radiator-2014-2019-fiesta-st-free-shipping

 

[M-Sport fan]

Just how cold does it get there in the winter (average daytime lows, and cold snaps)?
I would NOT go lower than a 180* stat regardless, for more reasons than just no heat/defrost.
In fact, I would not even do a 180* thermostat in any place cooler than the south/desert southwest, especially if you change out to an aftermarket radiator, which is actually easier/quicker a job to do than the thermostat is, anyway.

(Due to the oil NEVER getting warm enough to 'boil off' all of the moisture/diluted fuel/crap in it, and the chance of carboning up the combustion chambers/valves/plugs, especially if you do a lot of 'short tripping' in the winter, and not a bunch of long, extended highway drives.)

 

[SrsBsns]

There's a wealth of information on this topic if you search. Basically, the stock rad is garbage and the only fix is to upgrade the radiator. The thermostat or things like an oil cooler are nice to have but are secondary to the radiator itself.

Mountune and Mishimoto have been the go-to standards with the Mountune being more $$ but also much easier to install. Now Whoosh has one that seems like it could really run away with the market for the design/price combo.

 

[SteveS]

Of course you could also run through the normal things before yanking your radiator for a $500 replacement or putting in a cooler thermostat. Like checking coolant levels, looking for air in the system, looking for coolant leaks, flushing the cooling system and refilling, checking hoses, consider the water pump which uses plastic blades.

 

[M-Sport fan]

Of course you could also run through the normal things before yanking your radiator for a $500 replacement or putting in a cooler thermostat. Like checking coolant levels, looking for air in the system, looking for coolant leaks, flushing the cooling system and refilling, checking hoses, consider the water pump which uses plastic blades.

That all should be done anyway, even if you are swapping radiators.

 

[scooter123]

Go with the Mountune radiator and stick with the OEM thermostat. The reasons for these recommendations are simple, the Mountune radiator has enogh reserve capacity to keep the engine operating at the ideal operating temperature in ANY in ambient temps of 20 F to 98 F. Actually it will likely do even higher temps but those have not happened in the past 2 years where I live.

So, why does maintaining the ideal temp matter? It matters because that is where the engine is most efficient. As a result you get better fuel mileage and very consistent peak power output. As far as tunes go my 2019 is on the factory tune but is equipped with the Montume intake and Intercooler. Using all season street 205-16/60R50 tires a second gear pull has the traction control at it's limit at full throttle. If I switch the TC off then 1st and a good portion of 2nd are smokers. BTW, my city mileage has been averaging 34.6 mpg for the past 6 months and highway mileage at 70 mph is running at 40.8 mpg on a level highway. To be honest I expected the larger radiator would keep the engine at the ideal thermostat setting and produce more consistent power results but I did not expect to see a 3 mpg mileage improvement in the city cycle. Now when I fill up it's usually at about 400-410 miles on a tank of city driving.

To sum it up you do spend a bit more for the Mountune radiator but you also get what you pay for. It fits well with the OEM fan assembly and it keeps the engine right at the perfect temp. From what I've seen here the Mishimoto requires a lot of gyrations and perhaps a new fan shroud (one post was using a Focus SVT assembly). As for the Whoosh unit, it's too new for me to comment on.

 

[haste]

/snip

I understand what you are saying, BUT there is no way we are all going to drive like grandpa and get that kind of MPG.

 

[Erick_V]

I understand what you are saying, BUT there is no way we are all going to drive like grandpa and get that kind of MPG.

On E30 I haven't seen over 300 out of a tank in FOREVER. I babied a whole tank just to see what I could do and I only got to 340 lol

I suggest running less coolant, more water and water wetter if you can get away with it and run the OEM thermostat. I run about 70/30 w/ water wetter and my coolant temps are great. If you still overheat I would get the rad and never look back. Super easy to install and you can do it on jacks in the garage

 

[M-Sport fan]

I suggest running less coolant, more water and water wetter if you can get away with it and run the OEM thermostat. I run about 70/30 w/ water wetter and my coolant temps are great.

That's great, and exactly what I would do as well if I lived in a climate like yours, especially if I was limited by stupid, draconian H/Street autocross rules, and could not install an aftermarket unit.

But in 2Noob4U's case, he may NOT be able to get away with only 30% coolant in the mix, especially for a 'peak' low which could be hit in his locale, in a car sitting outside during the night (or even the day while at a job).

 

[2Noob4U]

Yeah I probably should've done this weird thing called a search in this forum. Feel free to close the thread