Pros and Cons of the Fiesta's Radiators

[Capri to ST]

While I'm sharing radiator part numbers, I have seen it said on here that our car uses the same radiator as the non ST Fiesta, but that doesn't seem to be the case, we do have a different part number for our radiator.
When I search on Tasca parts, the part number for a non-ST Fiesta radiator is listed as follows-
Radiator
AE8Z-8005-B
Without turbo. Fiesta.

When I search on there for a radiator for our ST Fiestas, it is listed this way-
Radiator
C1BZ-8005-A
Fiesta. With turbo.

Note that the two parts listings distinguish that one is without a turbo, and one is with a turbo.

https://www.tascaparts.com/v-2016-f...4-gas/cooling-system--radiator-and-components
https://www.tascaparts.com/v-2016-f...4-gas/cooling-system--radiator-and-components

 

[FiestaSTdude]

So the mountune radiator is in, trimming the bottom tabs on the fan shroud was a pain and I bent a few fins sliding it in but other than that it was pretty straightforward. I’m refilling the coolant per this video. The coolant refill part is at the very end

View: https://youtu.be/0RfkBhmwfNo


My coolant temperature is sitting at 185 while idling but I don’t get any hot air. Is there something I’m missing in the refill process?

Also, does this count as a coolant change? I’m not sure if it all comes out, but since I’m replacing so much of it, it should be much better than if I didn’t do the radiator swap.

 

[scooter123]

You are not getting any heat because you didn't vacuum fill the cooling system. As a result you have a giant air bubble in your heater core. The best way to fill these systems is with a Vacuum filler powered by an air compressor. Note, you will need a 5 gallon bucket to put the fresh coolant in. Because once you have pulled a full vacuum into the cooling system and open the valve to the bucket it will mostly empty in about 10 seconds. BTW, two gallons of coolant will provide a good fill but I suggest having an extra gallon of reserve in that 5 gallon bucket because you do NOT want to suck air into the cooling system. Also be aware that there is an overflow vent on the bottom of the reservoir that needs to be blocked off with a bit of electrical tape or you won't pull a vacuum on the cooling system. That tank is mounted with friction tabs so a firm pull straight up will release it and allow you to flip the tank over to tape up that vent. Note, it's about a 3/16 inch hole so the tape will NOT get sucked into the hole.

 

[FiestaSTdude]

You are not getting any heat because you didn't vacuum fill the cooling system. As a result you have a giant air bubble in your heater core. The best way to fill these systems is with a Vacuum filler powered by an air compressor. Note, you will need a 5 gallon bucket to put the fresh coolant in. Because once you have pulled a full vacuum into the cooling system and open the valve to the bucket it will mostly empty in about 10 seconds. BTW, two gallons of coolant will provide a good fill but I suggest having an extra gallon of reserve in that 5 gallon bucket because you do NOT want to suck air into the cooling system. Also be aware that there is an overflow vent on the bottom of the reservoir that needs to be blocked off with a bit of electrical tape or you won't pull a vacuum on the cooling system. That tank is mounted with friction tabs so a firm pull straight up will release it and allow you to flip the tank over to tape up that vent. Note, it's about a 3/16 inch hole so the tape will NOT get sucked into the hole.

Thanks, I actually ended up doing it without a vacuum filler because I didn’t have one. Somehow coolant made its way into the heater core because I’m now getting hot air.

 

[Geebs]

You are not getting any heat because you didn't vacuum fill the cooling system. As a result you have a giant air bubble in your heater core. The best way to fill these systems is with a Vacuum filler powered by an air compressor. Note, you will need a 5 gallon bucket to put the fresh coolant in. Because once you have pulled a full vacuum into the cooling system and open the valve to the bucket it will mostly empty in about 10 seconds. BTW, two gallons of coolant will provide a good fill but I suggest having an extra gallon of reserve in that 5 gallon bucket because you do NOT want to suck air into the cooling system. Also be aware that there is an overflow vent on the bottom of the reservoir that needs to be blocked off with a bit of electrical tape or you won't pull a vacuum on the cooling system. That tank is mounted with friction tabs so a firm pull straight up will release it and allow you to flip the tank over to tape up that vent. Note, it's about a 3/16 inch hole so the tape will NOT get sucked into the hole.

No offense but this is way more complicated than it needs to be! I replaced my rad last year with a mountune unit. I simply filled the reservoir until it stopped taking fluid, ran the car up to operating temperature and burped the system! Added more fluid as needed and repeated the procedure. Took maybe 4 burps until it stopped spitting air....DONE. No issues at all.

 

[FiestaSTdude]

New radiator is in, I haven’t driven it too much but I’m already noticing lower temps. The mountune radiator looks significantly better and more durable than the oem one.

 

[FiestaSTdude]

Now that I’ve had the mountune radiator for several months, I’m very glad I upgraded. NC is pretty hot right now (90s) and even with that coolant temps have been great, normally between 185 and 200 depending on how hard I’m driving. The temperature also drops off very quickly after doing a pull, which the stock radiator didn’t do. Also, I’m always running the ac and this radiator has no issues handling that even with aggressive driving.