just installed koyo radiator, question now.

[niSm095]

I just installed a koyo radiator on my sr, now I'm wondering one thing, should the car (temperature wise) be running cooler, or will the needle pretty much sit where it was before on the temp gauge and just provide greater cooling efficiency?

[niSm095]

also, I've been told to check the coolant temp sensor, so I'll go ahead and change that, can anyone show me a picture of where it is? on the SR?

[chlatboy]

if you installed a Koyo and you are using hte stock gauge, I would say that the needle will stay in teh same area. Since the stock guage is pretty inaccurate, you wont be able to see it from there. However, it will provide better cooling. If you are using an aftermarket guage, you will be able to tell.

[g6civcx]

I just installed a koyo radiator on my sr, should the car (temperature wise) be running cooler, or will the needle pretty much sit where it was before on the temp gauge and just provide greater cooling efficiency?

The car should be able to at least maintain a steady temperature. The engine operates best at a certain temperature. Above or below that and the engine isn't efficient. Overcooling or overheating isn't good.

Should it be running cooler? I don't know. Cooler than what? Stock? Other brands of radiator?

What temp gauge, OEM or aftermarket? The OEM gauge is very inaccurate, and is only a 3 step sensor, i.e. it will only show low, medium, and high. Anything in between won't show up. So at the medium mark there is a lot of temperature variation.

can anyone show me a picture of where it is? on the SR?

The SR has 2 engine temperature sensors: one for the gauge and one for the ECU. Which one are you asking about?

They're both clustered around the water inlet on the lower radiator hose and thermostat area. The gauge sensor has 1 wire while the ECU sensor has 2 wires.


This one shows the ECU sensor. The gauge sensor is next to it.
http://www.frsport.com/DIF_Dual_Fan_Controller_Install_on_S13_S14_240SX_t _22.html

[Chernobyl]

Your thermostat should control the engine temperature. Installing a more efficient radiator shouldn't change that.

Once you're doing laps on the track and your thermostat is open all the time, your new radiator will cool better and not allow the engine to overheat.

[ctm_motortrends]

Needle stays the same but the car should be running a little cooler. Also I used a nismo thermostat and that seem to be working to keep the car cooler.

[Bryants95240sx]

You most likely wont notice a diffrence driving around on the street, but if you track the car you after some laps the heatsoak wont be near as bad if you were to have a stock rad.

[kognition]

Yup if you do track your car, you should pick up an aftermarket water temp gauge so you will have a better idea of the temp fluctuations. I don't use a sensor in my setup (track car) so i use a toggle switch. Also consider getting an oil cooler if you are concerned about engine temps, then the larger capacity oil pan.

[gotta240]

cognition-please explain why you dont use a temp sensor and what a toggle is for? Or did you mean you only use an aftermarket temp sensor/guage with a toggle for the fan?

[g6civcx]

please explain why you dont use a temp sensor and what a toggle is for? Or did you mean you only use an aftermarket temp sensor/guage with a toggle for the fan?

The temperature sensor turns on the fan when coolant temperature exceeds a certain threshold. Kognition prefers to have the fan running all the time regardless of coolant temperature when he trigers the toggle switch.

This setup is not suited for street driving because at steady highway cruising, some fans cannot turn quickly enough. This creates a high pressure area behind the radiator, and air will go around instead of through the radiator.

A slow-moving fan can act like a wall that blocks air from coming through the radiator. What you need is for the fan to freewheel so there is a low pressure area behind the radiator to encourage air to go through instead of around the radiator.

It depends on the fan and the aero setup. Most high quality parts don't have this problem.

[niSm095]

thanks for the help everyone. To clarify a couple things, I'm talking about using the stock gauge, and "normal" temperature as compared to the stock radiator.

thanks for the info on the coolant temp sensor. Just to give you guys some more background as to why I changed out the radiator now. About a month ago, I had driven the car to work, which is about 8 miles away, 6 or so of it on the interstate. I got to work fine, then on the way home that evening (ambient temperature outside about 68) on the interstate, the temp needle on the dash starts going up. I pulled off the interstate, checked to make sure nothing was blocking the radiator, etc etc. Started the car back up after about 10 minutes, and only got about half a mile before it started overheating again, this time faster.

I parked it on the side of the interstate, came back the next day, quickly got the car home after it had time to cool completely, and decided to change the thermostat. I replaced the thermostat with a generic one I found at oreilley's, sealed everything up, refilled the fluid and bled the system. For the next week or so everything ran fine, I noticed that the needle on the temp gauge read slightly higher than it used to and attributed that to the thermostat having a higher temperature at which it opened. So, last saturday afternoon the car began overheating again. I got on the interstate about the same place I get off to go to work, cut the heater on full blast and managed to get home. At that point I found a new radiator and put it in this weekend. Anybody have any idea if there may be an underlying problem here?

[420sx]

have to bleed the cooling system. its a bitch. getting all the air out. u can install an expasion tank and it will self bleed.

your next investment should be aftermarket water temp gauge. its a must for anyone doing anything to their car

[g6civcx]

have to bleed the cooling system. its a bitch. getting all the air out. u can install an expasion tank and it will self bleed.

your next investment should be aftermarket water temp gauge. its a must for anyone doing anything to their car

+1. it takes a while to bleed so you have to be patient.

[gotta240]

An "underlying" problem could be the h20 pump or radiator...thats about it. Is there ANY leakage from the pinhole on the bottom of the h20 pump?

[kognition]

That's right, my car is only set up for running laps as fast as i can. So what i have learned from this is that the only thing i can really pay attention to
when i am driving is the tach light. I only run in the Redline events right now, so you do 5 laps consecutively. 1 warm up, 3 hot laps, and a cool down lap. I am not very confident in water temp sensors response to cool my water on the track. When you need your water as cool as possible and as fast as possible. For the street, a toggle would really draw unwanted load on the battery. But alot of drivers run a toggle setup on the track.
But back to your question, yes the Koyo will dissipate heat better than stock, and a good dual fan setup will really make an improvement.

[niSm095]

+1. it takes a while to bleed so you have to be patient.

I tried to bleed the coolant, I opened the screw for the valve and let the car idle for about 4 minutes and nothing started burbling out, so I loosened the screw a bit more with the car running, and some liquid bubbled, so I considered it good to go, should I bleed it again but wait until fluid is running out of the valve?

[babowc]

hm
i installed my koyo and now its running way too cool.
keep in mind, this is on a stock ka.

on the freeway, the temps go dowwwnn.
if i run long enough, it'll go down to the bottom.

[kevtrinh]

yeah ur guage sucks.

[projectRDM]

I tried to bleed the coolant, I opened the screw for the valve and let the car idle for about 4 minutes and nothing started burbling out, so I loosened the screw a bit more with the car running, and some liquid bubbled, so I considered it good to go, should I bleed it again but wait until fluid is running out of the valve?

Unless you're God, you didn't get it. Bleeding a KA takes a good 20 minutes at least.

[s13_gearhead]

Unless you're God, you didn't get it. Bleeding a KA takes a good 20 minutes at least.

Usually takes me about 20 minutes as well to fully bleed a KA, though I've never actually seen a 'proper procedure' for performing this. Usually I warm up the engine, adding coolant as the water pump cycles it into the engine, and then turn the heater on to full blast hot so it'll travel thoroughly into the heater core.

I know you (R240NA) probably know the proper way to do it, would you mind giving a quick step by step on what to do to fully bleed a KA, or link to a post that does?

[niSm095]

not a KA, its an SR. I mentioned that up there. Should it still take about as long?

[projectRDM]

SRs don't have the air pocket issue as bad, but they still can take a while. For either car I just jack the front end up as high as I can and keep pouring coolant in as it's displaced with air.

[slideways2004]

sr is not as bad as ka. on the ka it should take about 20-30 min. if its not taking that long, you are not doing it complete. in the ka, you have to go back and forth on hot and cold so coolant can circulate through everything. first time i did an sr, i was shocked at how much easier it was than a ka

[niSm095]

well, it ended up still taking about 20 minutes all in all. I bled it, then took it out on the interstate. Interestingly enough, when I got up to 70+ for a sustained period of time, the temp needle fell all the way down to cold.

[ranger240]

Anybody have any idea if there may be an underlying problem here?

you replaced your radiator cap before tearing out the oem rad right?

[niSm095]

nope. Just got rid of it. It was in garbage condition anyway. With little to no force, if I dragged my finger down a column of fins, they collapsed and turned to powder.

[Rookie84]

My sr temp needle doesn't like going up..

Do I need a new thermostat or an aftermarket gauge?

[420sx]

yea i hate bleeding this shit. i ordered an expansion tank so i dont ever have to do it. i bled it theres still air but its only jumping 2-3 c so its ok right now.

[niSm095]

i was thinking about an expansion tank to match the oil catch can i got from greddy. I haven't mounted the can yet, waiting on my front mount to get here so the SMIC piping is out of the way. what expansion tank did you get?

[Gearhead_42]

well, it ended up still taking about 20 minutes all in all. I bled it, then took it out on the interstate. Interestingly enough, when I got up to 70+ for a sustained period of time, the temp needle fell all the way down to cold.

If this is happening you either have no thermostat or a blown thermostat... replace it now, or the engine will never run efficiently. Use either OE or the Nismo if you want an "upgrade".

[niSm095]

that doesn't make any sense though...I replaced it less than a month ago

[Gearhead_42]

that doesn't make any sense though...I replaced it less than a month ago

I'd bet on this
I replaced the thermostat with a generic one I found at oreilley's, sealed everything up
being the explanation.

Old proverb, "He who buy cheap thermostat pay twice." OE replacement is what, $12? Nismo is $60-ish, drops temps pretty well in higher performance applications.

Be careful with the sealant, as with threadlock less is more... silicone sealer and coolant does funny things, and could easily stick open an otherwise functioning thermostat. A thin film is all you need to seal the housing...

Edit for fumble fingered typing

[chmercer]

do you actually have a temp gauge? or by temp gauge do you mean "stock mystery needle that shows the same value between 160 and 220 degrees"

[420sx]

i was thinking about an expansion tank to match the oil catch can i got from greddy. I haven't mounted the can yet, waiting on my front mount to get here so the SMIC piping is out of the way. what expansion tank did you get?

greddy .

[niSm095]

do you actually have a temp gauge? or by temp gauge do you mean "stock mystery needle that shows the same value between 160 and 220 degrees"

unfortunatly I mean the latter of the two.

I'm replacing the coolant temp sensors today, If that's not the root of the problem, I found someone who will get me a nismo thermostat for a good price.

[niSm095]

Okay, so here's what has happened since.

To resolve the issue of the temperature dropping on the interstate, I went to my friend who assisted me in changing the thermometer. We agree that we aren't sure if the thermometer was lined up correctly upon installation, with the floating valve at the top. So we took it apart again tonight, find that it was pointing to 9 o clock when it should have been pointing to 12 o clock. Maybe an issue, maybe it wasn't. I dropped the thermostat on accident, went ahead and bought another just to be on the safe side. Installed it. Refilled coolant, bled the system...

Then, we went to drive around, test it out. As we got on the interstate I noticed the factory needle pointing a little higher than it should have been, and as we got on the interstate it slowly rose more. About 3 exits down the interstate, I got off, and started through some stop lights. At first it cooled a little, then about 1/4 mile down the road it began overheating again.

So we pulled off and opened the hood, checking first for leaks. No leaks whatsoever. Then we notice a bubbling sound from the back of the engine. Easiest way to describe the sound: if you were trying to force air/water through a straw, then bent the straw as it was passing through, there would be a gurgling sound. (In this case, more like hot, bubbling liquid). It sounds like the noise is coming from somewhere along the heater hoses, but it's too dark to see anything.

So now what we're thinking is that perhaps a heater hose is crimped, not allowing enough coolant through at higher speeds, as the engine is working harder, but at idle and low speeds, it doesnt need as much coolant, so the stinted flow of coolant is enough. Is that bizarre? Could that actually be the problem?

Only other option in the system are the temp sensors. And I planned on changing those tonight too, but ran out of daylight to continue working. Now that we heard the bubbling though, it doesn't seem to explain the problem. Although, it did seem to explain the earlier issue of the temperature dropping to cold on the interstate.

Help? Input?

[niSm095]

anybody?



msglngth