Help me figure out why my coolant temp is so high
Thread Starter
Elite Member
iTrader: (30)
Joined: Aug 2007
Posts: 7,329
Total Cats: 12
From: Va Beach
Motor has 180 miles since being built. Coolant reroute, koyo rad and as good ducting as a street car should ever need. The only thing I can think of is the location of the temp sensor at the back of the head is getting heat soaked. Any other suggestions? I'm seeing temps in excess of 220 and ambient temp is 90.
I had a turbo 99 miata, no air guide, no undertray, no reroute, stock radiator. And it was fine too, until I turned on the air conditioner.
Joined: Oct 2011
Posts: 5,717
Total Cats: 830
From: Detroit (the part with no rules or laws)
What head @ head gasket.
I also found that getting all the air bubbles out of my system with the reroute and turbo was a pain. I have literally the worst radiator ever made and i'm not hitting 220 regularly. I have to really be forcing it to hit that temp.
And did you wire your fans to come on together, instead of just the one?
Are you built and boosted though?
What head @ head gasket.
I also found that getting all the air bubbles out of my system with the reroute and turbo was a pain. I have literally the worst radiator ever made and i'm not hitting 220 regularly. I have to really be forcing it to hit that temp.
And did you wire your fans to come on together, instead of just the one?
What head @ head gasket.
I also found that getting all the air bubbles out of my system with the reroute and turbo was a pain. I have literally the worst radiator ever made and i'm not hitting 220 regularly. I have to really be forcing it to hit that temp.
And did you wire your fans to come on together, instead of just the one?
BP05 head, OEM NA8 headgasket,
Fans are on separate outputs from MS3x, turn on temps are staggered but both will be on if necessary.
When is your water temp high? All the time? What psi is your rad cap? How did you bleed the system? Did you ever stick a wrag or plug into any cooling ports big or small? Stock temp sender location would see less heat soak due to the reroute allowing the heat back there to escape sooner. hence why you did a reroute. Is your thermostat inline and is it facing the right direction/normal warm up time?
Thread Starter
Elite Member
iTrader: (30)
Joined: Aug 2007
Posts: 7,329
Total Cats: 12
From: Va Beach
When is your water temp high? All the time? What psi is your rad cap? How did you bleed the system? Did you ever stick a wrag or plug into any cooling ports big or small? Stock temp sender location would see less heat soak due to the reroute allowing the heat back there to escape sooner. hence why you did a reroute. Is your thermostat inline and is it facing the right direction/normal warm up time?
Water temp is always high imo. i just took a 45 minute cruise, when moving steadily temps hover between 190-193. As soon as I come to a stop they shoot up over 200 and will slowly continue up. Never stuck anything in any ports (hopefully engine builder did not either). Thermostat is in correctly although now I'm doubting myself. Warm up time is normal and it will take a good 20 minutes to get up to 200 after a cold start.
Joined: Oct 2011
Posts: 5,717
Total Cats: 830
From: Detroit (the part with no rules or laws)
So i have to run both fans at once in 90+F heat when idling / in traffic. Also, i needed the shroud for the fans. That helped more than without. Again, i have the worst radiator ever made, not sure how much worse the Koyo is.
MS3 base tune doesn't turn on fans until 220F. So if you want the car to stay cooler when you come to a stop, go into the tune and adjust the turn-on point.
Thread Starter
Elite Member
iTrader: (30)
Joined: Aug 2007
Posts: 7,329
Total Cats: 12
From: Va Beach
It takes a few miles of driving to get temps into low 190s, soon as i come to a stop temps quickly rise past 200, temp will continue to rise the longer im sitting idle. Fans are set to come on at 185.
Remote thermostat or is it on the back of the head? I've had major issues with the M-tuned setup, however that's usually more of huge sways in temps, as the thermostat reacts so slowly in that location.
Take that panel off that doesn't allow airflow over the IC. the bottom pan and side panels to keep air from going around radiator is what you want. You aren't allowing enough fresh air the the radiator imo. Also anything under 200 cruise is great at 90* ambient. Remove that panel and expect a slight difference.
Yes, definitely pull that panel. If anything, you want that area more open, not less. Also, do you still have the OEM fan? The OEM fan is much better than most aftermarket fans (not sure what type you have in the picture). Worth a try, but make sure the motor on the OEM fan is fresh.
Thread Starter
Elite Member
iTrader: (30)
Joined: Aug 2007
Posts: 7,329
Total Cats: 12
From: Va Beach
Take that panel off that doesn't allow airflow over the IC. the bottom pan and side panels to keep air from going around radiator is what you want. You aren't allowing enough fresh air the the radiator imo. Also anything under 200 cruise is great at 90* ambient. Remove that panel and expect a slight difference.
Yes, definitely pull that panel. If anything, you want that area more open, not less. Also, do you still have the OEM fan? The OEM fan is much better than most aftermarket fans (not sure what type you have in the picture). Worth a try, but make sure the motor on the OEM fan is fresh.
How did you burp the system?
Put on the stock fan as a replacement. Sitting at idle you should have zero issues with temps getting up to whatever you have your fan set at to turn on at. 2 stock fans should have zero issue pulling air through IC/AC/radiator and keeping temps in line.
Put on the stock fan as a replacement. Sitting at idle you should have zero issues with temps getting up to whatever you have your fan set at to turn on at. 2 stock fans should have zero issue pulling air through IC/AC/radiator and keeping temps in line.
Thread Starter
Elite Member
iTrader: (30)
Joined: Aug 2007
Posts: 7,329
Total Cats: 12
From: Va Beach
How did you burp the system?
Put on the stock fan as a replacement. Sitting at idle you should have zero issues with temps getting up to whatever you have your fan set at to turn on at. 2 stock fans should have zero issue pulling air through IC/AC/radiator and keeping temps in line.
Put on the stock fan as a replacement. Sitting at idle you should have zero issues with temps getting up to whatever you have your fan set at to turn on at. 2 stock fans should have zero issue pulling air through IC/AC/radiator and keeping temps in line.







