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What are your temp readings?

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Old 06-19-08, 10:07 AM
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Question What are your temp readings?

i,ve been reading about alot of coolant problems & still not really sure of what temp is proper operating temp, recently added aftermarket guage & would like to know what temp everyone is running, just normal everyday driving, minor upgrades, thanks
Old 06-19-08, 11:30 AM
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180-220
Old 06-19-08, 11:53 AM
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In 112 degree weather here in AZ normal street driving/minor boosting, mine doesn't go above 205.
Old 06-19-08, 01:34 PM
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I agree with BillM's range of temps, but what is "normal" within that range is dependent on the car's condition, state of tune and what (if any) modifications you've done such as FC Thermoswitch, larger radiator, coolant to water ratio, ambient temps, number of oil coolers, etc.
Old 06-19-08, 03:28 PM
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Originally Posted by baggedoutmazda
i,ve been reading about alot of coolant problems & still not really sure of what temp is proper operating temp, recently added aftermarket guage & would like to know what temp everyone is running, just normal everyday driving, minor upgrades, thanks
I assume you have read this from the Big Fat FD Cooling Thread.

"Optimum Temps
65C (150F): too cold. According to service manual, EGR valve is non-operational below 150F, "to improve drivability when cold."
82C (180F): getting warm. Thermostat begins to open, circulating coolant through the radiator. Some coolant is still bypassing the radiator.
95C (203F): fully warm. Thermostat is fully open, not bypassing the radiator at all.
100C (212F): boiling point of pure water at atmospheric pressure.
105C (221F): getting hot. Stock ECU will activate fans to cool the car down. Fan speed will be low, or medium (if A/C is already on).
108C (226F): hot. Stock 93-95 coolant thermoswitch activates, changing fan speeds from low>> medium (or med>>high if A/C is already on) (switching to an FC thermoswitch will change this temp to 203F)
115C (240F): getting dangerous. OEM temp gauge begins to rise.
117C (243F): dangerous. boiling point of pure water with 13psi pressure cap.
121C (250F): too hot. OEM temp gauge will point to white line. Boiling point of pure water with 16psi pressure cap.
124C (256F): way too hot. Boiling point of pure water with 19psi pressure cap. Boiling point of 50/50 coolant mix with 13psi pressure cap.
127C (260F): way too hot. OEM temp gauge will point to red line."

During regular driving around the suburbs, I actually have to work to get my water temps up to 180. During cruise, it is usually is just under 180. If I am driving hard on the freeway with lots of boost, then I'll see the temps to up to 220F, but it drops right back down as soon as I drive sanely for a minute (ie 85 mph in 5th gear).
Old 06-19-08, 06:06 PM
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i guess i was too busy reading peoples cooling problems to find that, thanks for the info, i have an aluminum rad [godspeed from e-bay], exhaust, cold air intake, no other mods, seeing 190f. on highway, as high as 220f. stop & go traffic, thanks again.
Old 06-20-08, 12:15 AM
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my car is usually around 83-85C just cruising around, havent really ran the car hard yet. This is with a fluidine radiator, fan mods, front mount intercooler, single turbo and all the basics
Old 06-20-08, 12:20 AM
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mine stays betweek 85-90c most of the time.

I forgot to mention, this is with a FMIC and a Koyo 3-core N Flow rad and no undertray.

Last edited by SLOASFK; 06-20-08 at 12:29 AM.
Old 06-20-08, 12:25 AM
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With the PFC and Datalogit I have set the fans to come on at 85C. Temperatures rarely go more than a few degrees beyond that even after multiple high boost runs. Shutdown heatsoak temperatures can be up to 110C but they drop quickly to the mid 80s after startup. Cooling system is stock.
Old 06-20-08, 12:44 AM
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stock except for aftermarket radiator. I'm seeing 90-100c in city driving on the PFC. I really think this thing is being inaccurate and will install another gauge in the block itself.
Old 06-20-08, 12:51 AM
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81-84c here
Old 06-20-08, 03:57 AM
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between 95 - 102 celcius here. texas gets too damn hot this time of year, this is average range i get at night time.
Old 06-20-08, 04:38 AM
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Originally Posted by moconnor
With the PFC and Datalogit I have set the fans to come on at 85C. Temperatures rarely go more than a few degrees beyond that even after multiple high boost runs. Shutdown heatsoak temperatures can be up to 110C but they drop quickly to the mid 80s after startup. Cooling system is stock.
I wonder why you have the fans come on at such a low temp. The thermostat doesn't open until about 82C. It isn't fully open until 95C. If you are adding more cooling to the rad with the fans at 85C, all you are really doing is keeping the thermostat from opening completely. Less coolant flow through the engine means less heat transfer and higher possibility of local hot spots in the engine. Seems to me that the range between 83C and 95C would be considered normal operating temps and the "best" temperature to operate at would be 95C. That would be the lowest temp possible with maximal coolant flow (at least with the stock thermostat).

I've just set my fans to come on at 90C. The rational is that the only time I go past 90C is when I'm under boost and then the temps will tend to jump up to close to 220. If the fans start to come on at 90C the temps should still reach 95C but not rise as quickly past that 95C mark. I'll see what it does at the autocross on Sunday.
Old 06-20-08, 05:05 AM
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freeway: 76-79*C
stop-and-go traffic: 82-87*C

my fans come on at 86*C

Pertinent mods:
Koyo radiator in slightly modified stock location with KS Auto Burnout II bumper (as well as the other 7 pieces)
stock hood
Pineapple oil sump
Efini y-pipe, downpipe, high-flow cat, RB dual
Old 06-20-08, 09:35 AM
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Originally Posted by dhays
I wonder why you have the fans come on at such a low temp. The thermostat doesn't open until about 82C. It isn't fully open until 95C. If you are adding more cooling to the rad with the fans at 85C, all you are really doing is keeping the thermostat from opening completely. Less coolant flow through the engine means less heat transfer and higher possibility of local hot spots in the engine. Seems to me that the range between 83C and 95C would be considered normal operating temps and the "best" temperature to operate at would be 95C. That would be the lowest temp possible with maximal coolant flow (at least with the stock thermostat).

I've just set my fans to come on at 90C. The rational is that the only time I go past 90C is when I'm under boost and then the temps will tend to jump up to close to 220. If the fans start to come on at 90C the temps should still reach 95C but not rise as quickly past that 95C mark. I'll see what it does at the autocross on Sunday.

I agree. Especially if you are running a SMIC or VMIC. Running my custom Vmount, my coolant temps hover between 82-88 C in highway driving. They only go higher if I get stuck in stop/go traffic. I set my fans to engage at 90C then 91 and 92 (IIRC).

Before my Vmount, I was using a Greddy FMIC with fans set to engage at 85C. I went through 2 sets of fans b/c they were constantly on at 85C. Typical coolant temps were 92+C in highway cruise and higher in stop/go traffic.
Old 06-20-08, 04:13 PM
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Originally Posted by gracer7-rx7
I agree. Especially if you are running a SMIC or VMIC. Running my custom Vmount, my coolant temps hover between 82-88 C in highway driving. They only go higher if I get stuck in stop/go traffic. I set my fans to engage at 90C then 91 and 92 (IIRC).

Before my Vmount, I was using a Greddy FMIC with fans set to engage at 85C. I went through 2 sets of fans b/c they were constantly on at 85C. Typical coolant temps were 92+C in highway cruise and higher in stop/go traffic.
The RE-medy water pump from Mazmart probably helps a bit too.
Old 06-20-08, 05:09 PM
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What temp would you need to reach to really worry about warped housings and/or blown water seals?

I ask because I managed to blow my 60A Rad Fan fuse the other day... didn't realize until after I picked up a friend and got stuck in traffic about two blocks from my house.. noticed the temp rising, but the fans not kicking on. Ended up hitting like 117-120 c before I got into the garage, popped the hood and turned her off...


Obviously I will be checking for all the tell tale signs once I replace the fuse and start the 7 again.
Old 06-20-08, 07:37 PM
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anyone know what the stock CFM is on the radiator fans? What temp drops have people seen switching to a dual oil cooler setup?
Old 06-20-08, 08:34 PM
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I am stumped --- @ if I start my car and let it idle for 15 minutes with the a/c off, it will get to about 114 C. but if I do that with the a/c on, it stays around 100c

I bought my car basically bone stock, the only mod the owner did was a straight through cat (and a new muffler).

I also believe that my OEM stock radiator is rusting from the inside; if I upgraded to a koyo / fluidine, do you think my normal operating temp's would go down?

The vacuum is good - around 19 - 20 inches at idle & 15-17 with a/c on.
Old 06-20-08, 11:17 PM
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well the AC runs one fan. Your other fan will come on at 95C. I have mine to come on at 90C and in stop go i get up to 105. All Stock.
Old 06-20-08, 11:27 PM
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Originally Posted by Rx72Heaven
well the AC runs one fan. Your other fan will come on at 95C. I have mine to come on at 90C and in stop go i get up to 105. All Stock.
Am I completely wrong here? I swear that both fans should run at the same time. The only thing that changes is the fan speed, not the number of fans that are running.
Old 06-21-08, 01:43 AM
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Originally Posted by spoolage
I am stumped --- @ if I start my car and let it idle for 15 minutes with the a/c off, it will get to about 114 C. but if I do that with the a/c on, it stays around 100c

I bought my car basically bone stock, the only mod the owner did was a straight through cat (and a new muffler).

I also believe that my OEM stock radiator is rusting from the inside; if I upgraded to a koyo / fluidine, do you think my normal operating temp's would go down?

The vacuum is good - around 19 - 20 inches at idle & 15-17 with a/c on.
Sounds like you have a problem with your fans or thermostat. Troubleshoot that first.

The rad only helps at speed really. The stock rad does a good job of cooling a mostly stock car. Do a few searches on that. Thicker rads actually make it more difficult for air to flow through the radiator and that really is what makes a radiator cool the fluids. It radiates the heat to the air coming through the rad.

By the way, anyone with coolant system questions really should read the thread in the FAQ link. Lots of good info in there.
Old 06-21-08, 10:14 AM
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^ no, both fans are independent
Old 06-21-08, 10:15 AM
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Originally Posted by Aeka GSR
anyone know what the stock CFM is on the radiator fans? What temp drops have people seen switching to a dual oil cooler setup?
I dont know the exact CFM the fans flow, but there are 4 blade and 5 blade versions and the 4 blade supposedly flow more air.

Originally Posted by spoolage
I am stumped --- @ if I start my car and let it idle for 15 minutes with the a/c off, it will get to about 114 C. but if I do that with the a/c on, it stays around 100c

I bought my car basically bone stock, the only mod the owner did was a straight through cat (and a new muffler).

I also believe that my OEM stock radiator is rusting from the inside; if I upgraded to a koyo / fluidine, do you think my normal operating temp's would go down?

The vacuum is good - around 19 - 20 inches at idle & 15-17 with a/c on.
The reason it goes down with the a/c on is because the fans turn on as soon as you turn the a/c on. This keeps it from reaching higher temperatures because it starts cooling it sooner. it's easier to cool keep coolant lower if you start cooling it at a lower temperature. Yes if you upgrade your radiator to a fluidine or koyo your normal operating temperature will be lower. It is a highly recommended upgrade.

Originally Posted by Rx72Heaven
well the AC runs one fan. Your other fan will come on at 95C. I have mine to come on at 90C and in stop go i get up to 105. All Stock.
Close but not quite, Both fans always run, or should run. If they aren't both turning on you have a problem. There are 4 relays on the system to control speeds low med and hi. One is controlled by the a/c one by a thermo sensor and 2 by the ECU (they work together basically as 1). The more relays on the higher the fan speed. This is covered in detail somewhere else check FAQ.

Originally Posted by dhays
Am I completely wrong here? I swear that both fans should run at the same time. The only thing that changes is the fan speed, not the number of fans that are running.
Yes thats correct
Originally Posted by gracer7-rx7
Sounds like you have a problem with your fans or thermostat. Troubleshoot that first.

The rad only helps at speed really. The stock rad does a good job of cooling a mostly stock car. Do a few searches on that. Thicker rads actually make it more difficult for air to flow through the radiator and that really is what makes a radiator cool the fluids. It radiates the heat to the air coming through the rad.

By the way, anyone with coolant system questions really should read the thread in the FAQ link. Lots of good info in there.
Thicker radiators also hold more coolant which makes it easier to cool. Overall a fluidine or koyo will cool better then a stock setup. Nether one will cool enough without air passing through, which is why we either need movement or the fans to come on. But the larger capacity more then offsets the ability for air to pass through
Old 06-21-08, 10:50 AM
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Originally Posted by fendamonky
What temp would you need to reach to really worry about warped housings and/or blown water seals?
Anybody know?


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