2016 1.6 overheating w/ a/c on and long interstate trips

[BlueMidnightst]

Hello all, i have a 2016 st in central IL, I've been having overheating issues and wanted to see if its a common issue and where to start. When i have the a/c on in about 80-90 degree weather the cars coolant temp shoots up quickly between 220-230 degrees driving in town or on the interstate and gets significantly worse if i idle long periods of time especially with ac on.I first noticed the over heating issue when i was sitting at work with the a/c on for about 20 mins and coolant light went on and it was at 250. Temps only reach 195-202 driving without a/c on if im driving on small 55 mph roads. Car is full on coolant no leaks what so ever and is not losing any. Radiator is not plugged on the outside nor the intercooler if it has any relation. Anyone have some tips or similar issues? Thanks yall. -Blue Midnight ST

 

[Dialcaliper]

Step one: burp the system with a vacuum pump or vacuum fill kit. Someone might have changed the coolant and not gotten all the air out, and this car tends to trap air if you just pour the coolant in, run the engine and call it good.

Step 2: Look for anything else funky with the cooling system, any codes, leaves and plant matter clogging the radiator, etc

Step 3: Aftermarket radiator. The FiST has a pretty mediocre stock radiator that was designed for a 120hp Fiesta and it’s not really adequate once you add a turbocharged engine with an intercooler in front of it. Lots of FiSTs have had overheating problems, even completely stock.

 

[FiestaSTdude]

I will also add another thing to look out for since it’s currently happening to me. I have a mountune radiator and rarely see temps over 200 even with the ac on. However recently my car overheated idling in traffic. I pulled over and found nothing wrong with the coolant level but my fan wasn’t running. It appears that my fan module on motor is having intermittent failures. Im planning on replacing the whole assembly tomorrow to see if that fixes it. I doubt this is your issue though and like dialcaliper say’s making sure that you don’t have an air bubble and upgrading your radiator are where I would start.

 

[Magnetic]

My car was overheating here in AZ with the insanely hot weather over the summer. I would def recommened getting a radiator upgrade. (mine is a 2016 as well)

I've had almost no overheating issues since then. Only time I got high temps was after 10 mins of hauling a$$ on my way to San Diego from AZ going up these *massive mountains in 100+ degree weather during the summer. I was basically in the 5K RPM range or higher the whole time. As soon as I let off it it dropped temps super fast.

But for city and canyon runs 0 issues. I'm thinking an oil cooler will be on order soon just to give a bit more cool. I'm thinking after that it should be enough to not worry about it anymore.

Here's the place to grab one. Take your pick or call Ron for a recommendation.

https://whoosh-motorsports.myshopify.com/collections/ford-fiesta-st-cooling