Water Temp question

[70YSR]

hey guys sorry if this is already somewhere else but i couldn't find it, i just wired up my gauges today and after working out that using the same supply for the lights affects the readings i disconnected the lights and it was more accurate. However i just want to check that the readings i'm getting is what i should be. so with stock radiator and fan can anyone tell me what temperature it should be reading on idle at running temp.. and whats the highest temp it should reach before requiring immediate cooling down.. also what should oil pressure be reading at running temp on idle?

p.s. its the upper radiator hose coolant temp i'm after if anyone knows.

cheers, pm or reply greatly appreciated

 

[spoonman]

This is not the official S15 stats this what my gauges read.
My water temp gauge is installed just after the thermostat in the main pipe. (upper rad hose) running a stock rad

if the air temp is about 16C - 18C, guage will read about 60C to 65C, and today being a hot day 28C the gauge read 80C, then after giving it a bit of a blat it got up to 85C, put the clutch in and coasted for about half a mile and temp dropped to 60C, if you are idling with everything at running temp the water temp will prob go up to about 80C, fan will cut in after that maybe about 90C. Water temp will fluctuate as you drive through different conditions. normal motorway cruising with air temp about 23 will prob sit at 70C - 80C.
Drive in -5 and you water temp gauge will prob not even get past 40C

 

[70YSR]

cool... mine is probably running slightly higher then that but could be the difference in gauges and send senders and what not.... but i guess i'll have to just observe what conditions makes it run at what temps for now and make sure it doesn't start spiking

 

[craig8585]

This is not the official S15 stats this what my gauges read.
My water temp gauge is installed just after the thermostat in the main pipe. (upper rad hose) running a stock rad

if the air temp is about 16C - 18C, guage will read about 60C to 65C, and today being a hot day 28C the gauge read 80C, then after giving it a bit of a blat it got up to 85C, put the clutch in and coasted for about half a mile and temp dropped to 60C, if you are idling with everything at running temp the water temp will prob go up to about 80C, fan will cut in after that maybe about 90C. Water temp will fluctuate as you drive through different conditions. normal motorway cruising with air temp about 23 will prob sit at 70C - 80C.
Drive in -5 and you water temp gauge will prob not even get past 40C

No, 60C is definatly too low for normal driving, and the outside air temp shouldnt have an impact on the running temp unless you are sitting at idle with your heaters on full blast. Have you got a low temp thermostat? Or it may be stuck partially open with temp fluctuations like that. Where do you have your temp sender?

The standard thermostat opens at 82C. Normal running temp is 82-90C and the electric fan that everybody thinks is just for the AC also kicks in at 95C and off at 90C as a last resort type thing to aid cooling. Once your up and running the outside air temp should not impact on the coolant temp. That is why we have thermostats.

 

[spoonman]

No, 60C is defiantly too low for normal driving, and the outside air temp shouldnt have an impact on the running temp unless you are sitting at idle with your heaters on full blast. Have you got a low temp thermostat? Or it may be stuck partially open with temp fluctuations like that. Where do you have your temp sender?

The standard thermostat opens at 82C. Normal running temp is 82-90C and the electric fan that everybody thinks is just for the AC also kicks in at 95C and off at 90C as a last resort type thing to aid cooling. Once your up and running the outside air temp should not impact on the coolant temp. That is why we have thermostats.

normal running temp for me is about 80C i have just noticed that on colder days if just driving the car sanely colder days cause the temp to drop to 60C - 65C,
test it out once your car is a proper running temp ( water 80-90C ) push the clutch in and coast untill the car gets down to about 30mph (50kph) and see if you water temp drops.

my sender is on the lower rad hose (i said upper before opps :rotfl this could have a lot to do with the fluctuations, is it better to install the sender on the other hose?

as pic shows sender is just below plenum

 

[spoonman]

just went for a blat to test something else, and the water temp ( under enthusiastic driving ) got to 85C air temp is 26C on way back (2 min) driving normally temp dropped back to approx 78C

 

[70YSR]

yeah mine is running at about 80, but after a few thrashes it gets up to about 85-87... i just wanted to pretty much know at what temperature i should be backing off and let it cool down... my sender is installed in the upper radiator hose.. just getting curious before i go give it a thrash around the drift track

 

[GUEST_JDM]

if it gets to 99c then start to worry, on the track ive seen up to 98 with the standard radiator which is why i through it out and now run a 50mm saber radiator

 

[spoonman]

yeah mine is running at about 80, but after a few thrashes it gets up to about 85-87... i just wanted to pretty much know at what temperature i should be backing off and let it cool down... my sender is installed in the upper radiator hose.. just getting curious before i go give it a thrash around the drift track

if you have a FMIC that might reduce the cooling ability a bit, but thats where a good alloy rad comes in

 

[craig8585]

normal running temp for me is about 80C i have just noticed that on colder days if just driving the car sanely colder days cause the temp to drop to 60C - 65C,
test it out once your car is a proper running temp ( water 80-90C ) push the clutch in and coast untill the car gets down to about 30mph (50kph) and see if you water temp drops.

my sender is on the lower rad hose (i said upper before opps :rotfl this could have a lot to do with the fluctuations, is it better to install the sender on the other hose?

Yeah, that will be why you get the fluctuating readings. If you install it in the bottom hose like you have, you will be reading the temp. of the water after it has passed through the rad. If it is in the top hose you will be reading the temp. of the water coming out of the engine. This is the one you should be concerned about as the bottom hose temp. is not much use.

The reason it reads so low when you are coasting is because when coasting the engine is doing verry little work and producing little heat. This means your thermostat will only be slightly open and the water will sit in the rad for much longer, cooling it a lot more. This will give you your low readings, especially on a cold day. When I coast my temp goes down to around 80C and stays there constantly whatever the outside temp.

 

[LuPix_S15]

I don't know what peoples' opinions are but that's why with gauges and sender units I buy Defi to ensure quality and precision etc.

Ok someone's gonna tell me it's the same cheap **** from a Chinese factory and I'm paying brand prices lol *waits in dejective state*

...

 

[craig8585]

I think Defi gauges are ace. You can do so much with them they are more than just gauges. Almost like data logging.

 

[spoonman]

my gauges are cheap, i just cant afford to buy things like Defi at the moment, for now a new rad hose so i can move the sensor.......

 

[_Wing_]

normal running temp for me is about 80C i have just noticed that on colder days if just driving the car sanely colder days cause the temp to drop to 60C - 65C,
test it out once your car is a proper running temp ( water 80-90C ) push the clutch in and coast untill the car gets down to about 30mph (50kph) and see if you water temp drops.

my sender is on the lower rad hose (i said upper before opps :rotfl this could have a lot to do with the fluctuations, is it better to install the sender on the other hose?

as pic shows sender is just below plenum

that's the problem - you're measuring water temps AFTER the radiator has done it's job. Move it to the top hose, closer to the block the better.

 

[spoonman]

for some stupid reason when i installed it i thought the flow was the other way, SPECIAL SPOONMAN:wave:

 

[spoonman]

Yeah, that will be why you get the fluctuating readings. If you install it in the bottom hose like you have, you will be reading the temp. of the water after it has passed through the rad. If it is in the top hose you will be reading the temp. of the water coming out of the engine. This is the one you should be concerned about as the bottom hose temp. is not much use.

The reason it reads so low when you are coasting is because when coasting the engine is doing verry little work and producing little heat. This means your thermostat will only be slightly open and the water will sit in the rad for much longer, cooling it a lot more. This will give you your low readings, especially on a cold day. When I coast my temp goes down to around 80C and stays there constantly whatever the outside temp.

In the process of putting the sensor in the wrong place i found out some info about how effective the standard RAD is. this in under normal driving with stock thermostat.
The temps are approx readings. this rad had done 110000ks and looks in really good cond

This is just basic info i noticed since i installed the sensor in wrong place.
this morning was the fist cold morning in a while 3C so i went for a blat and noticed that the temp lowest reading being 40C did not move past 50 even when giving in hell.
Oil temp for my car is 70-75C on frosty day 95-105 on hot day when driving hard

Air temp______ Water temp fed back to engine
24C +________ 80C (would not go past that)
18-24C_______ 70-80C
10-17C _______ 60-70C
5-9C _________ 40-60C
-0-4C_________ 10-40C (40 being the lowest reading on the gauge)

Under Fun driving rad effectiveness is

24C+ _________80-85C (never saw gauge get above that even on hottest day)
18-24C _______75-80C
10-17C _______65-75C
5-9C _________55-60C
-0-4C ________10-50C

 

[_Wing_]

Thanks for posting that data up!
There isn't all that much wrong with the OEM radiator, it's great actually... as you can see above.


Problems start popping up when you drive it hard (obviously) and when you start pushing lots more power (again... obviously). But in the hunt for more power you decrease it's efficiency by adding a huge FMIC, removing the undertray to fit the FMIC, maybe an oil cooler (don't put it here BTW), and maybe switching to thermo fans/removing the clutch fan and shrouding. I also noticed that some Australian-based s15's (don't know about other countries) have been cheated on air guides. Little bit here and little bit there and off goes the radiator's efficiency.