sr20det cooling

[mynismo]

i have a problem with my s13 redtop cooling (im sure im the millionth person by now).

i have a koyo aluminum radiator with 220 twin flex-a-lites, wired to a painless performance thermostat fan relay drilled into the radiator right next to the lower radiator hose which is supposed to come on at 200F and off at 185F. my water temp gauge is a techtom cmx-100 which reads off the stock sensor, which i know is reading the correct temp.

it was running PERFECT after i flushed the cooling system with derex flush fluid. as read by the techtom, the fans would come on at 195F and off at 180F. it was running just fine and dandy for two weeks.

i had to get rid of the derex fluid and the fact that it was all water, so i drained it out, flushed it with water and filled it up with 50/50 and water wetter using the correct bleeding procedure for this motor. temp goes up to 177F, which i believe is when the thermostat opens, stays there for a little bit, then starts to move upwards slowly. im keeping heater on H on level 4 to let the heat out. if i let it idle with heater on full blast it goes to 195F and stays there (for a good 1.5 hours) with radiator cap on or off. if i turn the heater off, the temp slowly rises and keeps going up (the fans don't come on). turn it back on, temp slowly goes back down to 195F.

the problem is that the fans just aren't coming on at idle. they were coming on before at 195F and it was all perfect until i had to change it to 50/50. during driving, the fans come on erraticly at different temps, inbetween 195F and 220F. if i idle they don't come on.

any clues? im losing my mind. i bled the system a good 10 times and this has taken up the last two full 8 hour days and its just not running like it was two days ago. im tempted to change the location of the thermostat for the fan into the upper radiator hose because for some reason the temperature before the car thermostat in the bottom radiator hose is not going up to 200F. the thermostat is brand new and has been working before just fine, and the car is not overheating with radiator cap off and heater on full blast. if it was a bad thermostat the temp would just completely rise and wouldn't stop.

what are your thermostat controlled fan setups? where do you put the thermostat for your fans? lower radiator hose? i would really like to know because i've just about had enough.

what i don't get... is that it was running PERFECT with the derex in there. i might just put it back in and call it a day.
Modified by mynismo at 6:30 PM 9/8/2004

[mynismo]

no one here has an sr20 with an e-fan setup?

[SmithSR]

Have you posted this in the RWD SR sub-forum?

If I don't see your thread there, I'll move this one, so the people viewing the SR section only will view it, fair enough?

[Def]

You need to mount the temp gauge in the upper radiator hose or somewhere near it. I had my Defi Link Water Temp gauge mounted in the lower hose and it would take a while to get up to temp due to free-standing convection(cools water down some). The upper radiator hose provides MUCH more reliable and stable temps.

[S13240]

I just have mine running constant.

[creophus]

I feel your pain on this. I just replaced my water pump, fans and thermostat. I have my fans wired to run constantly. I recommend doing that. I also have an SR(duh!) and Flex-A-Lite 220s.

[mynismo]

Quote »You need to mount the temp gauge in the upper radiator hose or somewhere near it. I had my Defi Link Water Temp gauge mounted in the lower hose and it would take a while to get up to temp due to free-standing convection(cools water down some). The upper radiator hose provides MUCH more reliable and stable temps. [/quote]actually, this isn't a water temp gauge. this is the thermostat for the fans. is it still ok to mount the thermostat for the fans in the upper radiator hose? if so i believe i need the blitz upper radiator hose.

my mechanic told me that thermostat for the fans needs to be in the lower radiator hose and that the water temp gauge needs to be tapped into the upper radiator hose.

any truth to this? isn't all that matters is the temp in the block?

running the fans all the time keeps the car below normal operating temp which is supposed to be not good for the car, and it also creates a turbulence so that the airflow cannot leave the bay. this is all what ive heard and read in many numerous places.

does anyone have their fans wired to a thermostat? is it possible to tap into the stock temp sensor (where is it located??)?

edit: i've researched and i think im going to get a blitz upper radiator hose with pivot water temp and fan controller. seems the best of both worlds. as of now temps aren't going above 208F which is fine but i think im still going to make the switch in a week or two.
Modified by mynismo at 5:37 PM 9/9/2004

[S13240]

running the fans all the time keeps the car below normal operating temp which is supposed to be not good for the car, and it also creates a turbulence so that the airflow cannot leave the bay. this is all what ive heard and read in many numerous places.Modified by mynismo at 5:37 PM 9/9/2004

How would you know it's keeping the car below normal operating temp? I've had my fan like that for 3 yrs and my engine still hasn't gone out on me yet. Experience over reading is better!

[mynismo]

yes, but you might not get optimal power. im sure you can do it, but it would never reach "peak" operating temperature.
Modified by mynismo at 2:20 PM 9/14/2004

[mynismo]

well, i got the pivot super temp controller.

IT SUCKS. don't get it.

just wire it to the ignition like s13240 says.. temps are great (177-188F).

i guess my mechanic was just full of a load of crap.

[240SXer]

My SR seems to cool fine. I'm running the stock radiator, stock clutch fan with no shroud. Except one time it was racing a mustang from 70-145 and it started creeping to around 1/2 way on the gauge. I assume it's because the pump sux after 6k, but it went down after a few minutes. I here there is some sort of mod you can do to the water pump to make it work better. But you guys have pretty awsome cooling setups to have any cooling problems. I don't get it.

[mynismo]

it was just a problem with the fan controller.... my mechanic is on crack. i wired them to the ignition now and cooling is PERFECT. i romp everywhere and temps never go above 188F.

as long as you bleed the system correctly and always have your fans on, you shouldn't have any cooling problems.

[Nismo_Freak]

it was just a problem with the fan controller.... my mechanic is on crack. i wired them to the ignition now and cooling is PERFECT. i romp everywhere and temps never go above 188F.

as long as you bleed the system correctly and always have your fans on, you shouldn't have any cooling problems.

FYI the idea of the fans is to click on once the coolant reaches a certain temp so that they can cool it. It does no good to wait till the radiator is filled with 200 deg. coolant to click on the fans, by then a good volume of the hot coolant will be going back into the motor to be heated further.

Thats why you run the thermocouple on the upper pipe because that is were coolant first enters the radiator, and that allows the fans to cool the warmer coolant.

[mynismo]

thats what i thought... but whoever did the swap said you're supposed to put it in the bottom hose. i thought he was wrong.

anyways, i did a test and it takes the same exact time to reach 177F if the fans are on or if they are off. its because the thermostat doesn't open until 170F and there is a few degrees difference between the coolant in the thermostat and coolant in the block. it doesn't matter if you have fans run all the time because 177F is already correct operating temp, you just need to cool everything off before it gets much hotter than that.

there's only a 6-7F degree difference between running the fans all the time or having them controlled by a fan controller. its not worth the extra work, money or effort for that little of a difference.

[creophus]