2015 ST overheating

[Fg2Civic]

Hey guys I have a 2015 Ford Fiesta st I am working on. Has 64k on it and vehicle is bone stock. It will over heat after normal operating temperature is reached with the a/c on. It gets up to 224 degrees and then goes up higher on acceleration until it reaches 240. I can then turn the heater on and it will slowly decline in temp. So I replaced the thermostat when removing the thermostat I found the spring retainer piece just laying there and the spring detached, replaced thermostat bled system. Went out to test drive and still same condition I have read things about radiator blockages and cyc 4 problems I am going to do a block test tomorrow and hopefully that gives me some insight. Any ideas or problems/fixes you guys have had for yours? Thanks

 

[re-rx7]

Check ac fan?

 

[Fg2Civic]

Yes fan is working correctly.

 

[Thirty-Two]

Just for some clarity.

Is it just with the a/c on, what about no a/c but hard driving and then a/c, what the increase/decrease in temp?
Highway speeds with light traffic? Heavy City Traffic?

Radiator blockages aren't that common but they will be apparent quickly and without necessarily having the a/c on. After running the car for just a short while hop out and check the heat (carefully) on all inlet/outlet hoses. If you have access to an infrared heat gun it would make it alot easier as you can track along the lines for any sudden drops/elevations.

Another thing interesting about the computer system in the car is that if I drive hard with the a/c at full blast after a while the a/c will decrease in power. Drive easy and the a/c blows arctic cold. Perhaps the defective thermo was wildly affecting the computer and all the car needs is a reset. I'm not entirely sure but I believe that pulling the battery for at least 10 min should reset these settings as it does reset much of everything else.

Other than that leakage, from cap or raditator, a/c system, hoses. Low fluid, bad fluid. Radiator fan not kicking in. Water pump...etc etc.

 

[Fg2Civic]

It happens with a/c on or off but more quickly with a/c on. I would say I was driving about 40-60 3.5k shifts so moderate driving replicates it. temp across the top of the radiator is 200 on both sides, 189 inside of coolant reservoir while the car is "reading" 230. Also I am not sure if the system is reset by having the battery unplugged but it was unplugged for a substantial amount of time due to replacing the thermostat and having to remove the alternator.

No signs of external leakage
Fluid is all new with the correct type, mixture and levels
Radiator fan is working with varrying speed

 

[grnmachine02]

What is the normal operating temp of these cars anyhow? Is 240 considered overheating? I know some cars operating temp is 220, and from what I understand the Fiesta fan doesn't even turn high speed on until 230.

 

[Fg2Civic]

I can guarantee that 240 is overheating that's when it starts to jump and to the warning

 

[grnmachine02]

I wasn't trying to say you were wrong, I was just wondering. How are you monitoring coolant temps? Through an Accessport, or did you install an actual temp gauge?

 

[2Cool]

Possible air in the system after the thermostat replacement. May want to pressure bleed it if you have the tools or a shop nearby that does.

 

[Fg2Civic]

I wasn't trying to say you were wrong, I was just wondering. How are you monitoring coolant temps? Through an Accessport, or did you install an actual temp gauge?

my bad XD I am using my matco maximus scanner to monitor

Possible air in the system after the thermostat replacement. May want to pressure bleed it if you have the tools or a shop nearby that does.

I was thinking that I tried following the procedure on alldata of holding it at 3500 rpm for 30 sec then off for 1 minute and repeat 5 times I will try to pressure bleed

 

[KentRatke]

I had serious overheating issues. Once I changed over to a larger intercooler and airbox, it seems to have helped.