• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!


What temperature qualifies for overheating? Whats a normal operating temp of Oil/Coolant?

Messages
367
Likes
46
Location
Huntington Beach
#1
So Sunday I was in the canyons, after some spirited driving and about a 6,000 ft climb I noticed my Oil/Coolant temps were both at about 240 ?f. So I pulled over, cranked the heat and let the car sit. What I want to know is was I right in doing that? Can I let both oil and coolant get hotter? Whats their normal operating temp, and what is the maximum I should allow?

The car never said it was overheating, I just normally don't see either temp rise above 220 ?f.
 


Messages
142
Likes
38
Location
Peoria
#2
I feel your pain right now. In everyday traffic here in Arizona summers (105-115 degrees) I regularly see 230-240 degrees without even beating on the car at all... These cars can't keep cool enough it seems, Most cars anything over 220-230 would start moving the needle past the normal "halfway" point on a coolant gauge. Fiesta seems to finally move past the "normal bars" range at 240+ Aluminium engines tend to have warped heads/head gasket failure sometimes complete engine failure around 265+ Scary that the fiesta is riding so close to that. I am waiting for another radiator option and probably at some point going to get rid of the crash bar and open up the grill all the way.
 


KKaWing

Active member
Messages
702
Likes
206
Location
Somewhere
#3
The car has a cylinder head temperature sensor. It is "trigger" based so can't read temps, just signals when it goes past a certain temperature. Basically the car will go into limp mode if that sensor is tripped, indicating overheat. I would however follow the severe schedule for oil changes as high heat "wears out" the oil quicker.
 


BRGT350

1000 Post Club
Messages
1,075
Likes
762
Location
Grand Haven
#4
My Mustang has the opposite issue, I have half of the radiator blocked off with cardboard, and can rarely get the coolant temp warm enough to open the thermostat and oil to get above 200'F. Most days in the summer it is stuck in the garage because it isn't warm enough to get the carb to kick down from high idle. I don't monitor coolant temp in my ST, only oil temp, and I have never seen it over 220ish. That is why I am so amazed by everyone saying they have overheating issues. They must drive their cars really hard or live in a much hotter climate than I do.
 


Messages
62
Likes
11
Location
Cupertino
#5
It might be better to keep driving the car while trying to cool it down. But maybe someone else can chime in about that.

And, normal operating temp should be around 200 for both coolant and oil. You should be letting it get up to that temp before spirited driving.

I was just tracking my car in 100f weather with the mishimoto radiator and oil cooler. My coolant barely went over 200 and my oil got to 230-240 before I went for cool down laps.
 


Siestarider

Senior Member
Messages
988
Likes
292
Location
Stuart
#6
At 90+ ambient I regularly see 240/255 water/oil at Fla tracks. Put heater on full blast and get 230/240. This with stock cooling but all gaps sealed so intake air is forced through heat exchangers. Car does not limp, but summertime tracking always use heater. C39 just came in today, so I will have to do something to add cooling. Will try redline water wetter and 100% water next, see how that goes.
 




Top