How high has your coolant temp reached?

[fabrizzio71]

Hi All,

I’m looking for some feedback here about coolant temps from those of you that monitor your data while driving. It’s been in the 90’s here, and since I live up a mountain, I have about 1200 feet elevation change of continuous climbing for several miles to get home. Monitoring coolant temps recently, and they are climbing well above 200 degrees. Today I saw 212. I was also being extremely gentle, was barely in boost etc. Is 212 cause for concern? I am looking into changing the grill, but should I also look into upgrading the radiator?

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[Yaminashi]

Highest temperature I've seen on my car is 182.

 

[das borgen]

I've seen up to 213deg while autocrossing. Even at 90deg ambient temps, the coolant temp easily falls back down to under 180deg even while idling at a standstill

 

[kimtyson]

Maybe your coolant to water mix isn't correct?

 

[alxgravel]

212-213 on traffic fan with tsp stage 1 starting at 203. The warm temp its 176-177. When pulling on map 3 seeing some time 185-190 but I have a 27won intake. It realy droped the motor temp down to 10 degree on warm day.

 

[fabrizzio71]

I've seen up to 213deg while autocrossing. Even at 90deg ambient temps, the coolant temp easily falls back down to under 180deg even while idling at a standstill

Thanks, when I pulled in my driveway, it came down some from 212 while idling but the cooling fan was not on. Do you know what temperature the fan comes on?

 

[das borgen]

Thanks, when I pulled in my driveway, it came down some from 212 while idling but the cooling fan was not on. Do you know what temperature the fan comes on?

Good question. I know the coolant temp sensor in the radiator outputs to the ECU and the ECU sends out a signal to the relay that powers the fan once the ECU sees that temp from the coolant temp sensor. I haven't yet been able to find that value, but I imagine it's well before 212.

If the fan is also a PWM (pulse width modulation) it may even come on at relatively low temps (as low as 180 to 185?) and the ECU adjust its fan speed according to coolant temp

How was your temp going down while idling if your cooling fan wasn't on? That doesn't make any sense without any airflow.

Also, is your fan coming on with the A/C? At least that should be happening.

 

[fabrizzio71]

Good question. I know the coolant temp sensor in the radiator outputs to the ECU and the ECU sends out a signal to the relay that powers the fan once the ECU sees that temp from the coolant temp sensor. I haven't yet been able to find that value, but I imagine it's well before 212.

If the fan is also a PWM (pulse width modulation) it may even come on at relatively low temps (as low as 180 to 185?) and the ECU adjust its fan speed according to coolant temp

How was your temp going down while idling if your cooling fan wasn't on? That doesn't make any sense without any airflow.

Also, is your fan coming on with the A/C? At least that should be happening.

Those are all good questions. The temp came back down some but then started to rise again. I don’t remember the exact temp. I always had it in my head that honda thermostats generally open around 175, and I expected 195 to be the temp when the cooling fan comes on. However, while driving, if the temp continues rising, cooling fan isn’t going to do more than the rushing air, it’s more for when idling. That’s why I ordered a new grill with the honeycomb opening-should be here end of August.

I will do a test today and see if I can get the fan to come on just idling. Will check on if fan comes on with the A/C also. I’ll report back.

 

[@thatblu_si]

Those are all good questions. The temp came back down some but then started to rise again. I don’t remember the exact temp. I always had it in my head that honda thermostats generally open around 175, and I expected 195 to be the temp when the cooling fan comes on. However, while driving, if the temp continues rising, cooling fan isn’t going to do more than the rushing air, it’s more for when idling. That’s why I ordered a new grill with the honeycomb opening-should be here end of August.

I will do a test today and see if I can get the fan to come on just idling. Will check on if fan comes on with the A/C also. I’ll report back.

I was eating some ice-cream in my car yesterday in a parking lot and decided to watch my coolant temps on the hondata app. I watched my coolant temps go up to 215, my fans kicked on and it dropped back down to 185-190. Honestly i wouldn't be to concerned unless it gets passed the 220-230 range. I also noticed my coolant temps rise just a bit when i get off the gas and the car leans out as it slows down, when the car is under light load and its receiving the proper AFR, the fuel in the cylinder actually helps keep cylinder temps in the right range. If you start running lean your cylinder temps will go up which is why my coolant temps increased just a bit when i let off the gas and let it slow down on its own. Running lean is also why alot of cars blow up, cylinder temps get to high, coolant temps get hot, and then you start dropping valve seats and blowing head gaskets. Just keep an eye on your coolant temps, AFR and knock, those are the three key readings you wana always be looking at.

 

[fabrizzio71]

Thanks. Well I just tested it. Cooling fan came on the second it hit 213 degrees F-brought it down to about 194 F very quickly and then cycled off. I’m glad I know this now. Also, for those interested, the thermostat opened at 177.8 degrees F. I’m glad I don’t have a problem.

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