[vixenlotus]

My car over heated on the highway the other day. Dealer said they could not find anything wrong. Anyone else having this problem? Car has 40k easy highway miles on it.

 

[reddog99]

I think that the ST cooling system capacity is marginal. A number of people have noted overheating under different conditions. Some have had malfunctioning parts, others have found nothing evidently wrong.

 

[Firesail]

I wonder how soon someone will make a higher capacity radiator for the ST. Mishimoto, maybe?

 

[yogerdt]

Like reddog99 said, the cooling system on the ST is marginal at best and Firesail, Mishimoto has a radiator already out for the ST. There are some youtube videos with people having it in if you want to see what they think about it.

 

[tubbyaz]

It's strange that I have not seen one hint of overheating here in Phoenix. Today I think is the 31st day this summer of 110+ degrees, and I have yet to see the temp gauge go over the normal mark. I've seen a few of these posts here, so I watch the temp pretty close.

Will keep the Mishimoto in mind if I ever experience an issue.

 

[reddog99]

My own ST does OK on level ground. But if it's 100 out while I'm climbing the mountains on the interstate, all bets are off. Yesterday, it got a good heat soak while running some errands in town in 103 temps. When I got back on the freeway going uphill, the car wouldn't go over 60 and the coolant temp was 248. It took a couple miles of right-lane travel with the semi-trucks to cool things down.

 

[FiST_To_The_Clutch]

The closest I got to overheating was sitting in traffic at about 85 degree ambient and the coolant got to 219. I got worried and had to turn on A/C as it forces the radiator fan to kick in for the condenser. After about 3 mins temp went down to about 185-188 and stayed that way no matter how long I sit in traffic (again, thanks to the radiator fan spinning).
What I have noticed (at least on my car, even though I already replaced the radiator fan relay for '16 model recall) is that if you don't have A/C on no matter how hot the coolant gets the system will NOT turn on the fan. I know our cars run hot because the coolant system is pressurized, blah-blah, but still there has to be a temperature threshold at which the system will open the thermostat AND kick the radiator fan on. So far I'm only able to force the fan on ONLY IF I turn A/C on, which is weird. 219 is as far as I pushed it, and frankly do not want to see "how far it goes" before overheating...

 

[FiST_To_The_Clutch]

As for overheating while going on the freeway, I was driving through about 103-105 degrees heat for a week, going uphill on the way home everyday against the wind in 5th at 3500 rpm pushing about 2-3.5 PSI of boost for about 5 mins straight with A/C on. Highest I've seen it climbed during that time was 197 and stayed that way until I got over the hill and shifted to 6th gear driving normally (i.e., no boost just vacuum). Typically during freeway commute whether hot or cold my coolant sits between 183-188 degrees.

 

[reddog99]

It is puzzling. Last year, I would have said that my car never overheats.
I've gone up & down these mountains literally hundreds of times, and this week is the first time I ever had heat problems. Why now & not other times? It's a mystery.

 

[DayJ]

It's strange that I have not seen one hint of overheating here in Phoenix. Today I think is the 31st day this summer of 110+ degrees, and I have yet to see the temp gauge go over the normal mark. I've seen a few of these posts here, so I watch the temp pretty close.

Will keep the Mishimoto in mind if I ever experience an issue.

I'm also in Phoenix and I have to watch it in stop and go traffic if temps are over 115 on the asphalt. What color is your FiST? Are you the white one near Melrose?

 

[Guest]

The closest I got to overheating was sitting in traffic at about 85 degree ambient and the coolant got to 219. I got worried and had to turn on A/C as it forces the radiator fan to kick in for the condenser. After about 3 mins temp went down to about 185-188 and stayed that way no matter how long I sit in traffic (again, thanks to the radiator fan spinning).
What I have noticed (at least on my car, even though I already replaced the radiator fan relay for '16 model recall) is that if you don't have A/C on no matter how hot the coolant gets the system will NOT turn on the fan. I know our cars run hot because the coolant system is pressurized, blah-blah, but still there has to be a temperature threshold at which the system will open the thermostat AND kick the radiator fan on. So far I'm only able to force the fan on ONLY IF I turn A/C on, which is weird. 219 is as far as I pushed it, and frankly do not want to see "how far it goes" before overheating...

Do you happen to have a recall number for the '16 model fan relay fix?

 

[BostonDriver]

Mishimoto has a higher capacity radiator and an oil cooler setup. Seems as though the cooling system is adequate for most everyone who hasn't modified the car or tuned their ecu. I've got a custom tune and what is now offered as the Mountune MR230 kit and during normal driving i never have overheating issues regardless of how hot or the traffic conditions, but take it to the track and I can only get about 3-4 hard laps in before the overheat light pops up. you can't really go by the stock gauge since it seems like it stays at the middle until it's in the 220 degree range and then comes on at 235 degrees. Just last weekend I put in the Mishimoto Oil Cooler Kit to see if that will help control track temps enough to not need to install the radiator. Since the sandwich plate they use isn't cooling the oil with the coolant it should separate the heating effect of the hot oil from the turbo warming the coolant during track use. Just under normal driving conditions I've noticed that the oil and coolant temps now fluctuate independent of each other rather than following each other. I've done a few pulls to see how sustained high boost affects temps and I see the oil temp rise quickly, but not the coolant so I'm hopeful that the radiator has enough cooling to keep it in the 220 (or below) range during track use. The oil cooler seems to be very effective at cooling the oil as well since I can watch the temps drop very quickly after those sustained boost runs.

 

[tubbyaz]

I'm also in Phoenix and I have to watch it in stop and go traffic if temps are over 115 on the asphalt. What color is your FiST? Are you the white one near Melrose?

Nope, Green Envy, and when I do drive it, it's mostly around N. PHX, work in N. Scottsdale. I mostly commute to work via bicycle though. Explains why I have only 19K miles three years after delivery.

 

[FiST_To_The_Clutch]

dubtactic, recall was 16B11, radiator fan relay. The whole thing took my dealer 6.5 minutes.

 

[OutOfDemo]

When I had mine I had the exact same problem. Got rid of mine after 10k. When the weather was warm enough I could get it to overheat on demand. High RPMs, low speed. So stop and go traffic. I could also feel it pull timing exiting the parking lot after work. The car would heat soak all day, and just he act of pulling away in first gear would cause big pulls in power. I got rid of it shortly after. If it would having those type of problems when new, I didn't want to deal with it in 50k miles.

 

[FiST_To_The_Clutch]

OutOfDemo, you might have gotten a lemon or either defective coolant system. Was yours 2016? Many received a radiator fan relay recall. But my FiST went through 3 months of 100+ degree summer weather in 2016 and did just fine, with A/C blasting for 1-2 hours a day every day highest coolant temps I've seen was 197. Keep in mind that when you use A/C the radiator fan is always on. To be honest I did not notice any timing being pulled this past summer since when it's that hot outside I drive like a granny. Maybe your radiator fan wasn't working?