KA24DE Cooling System Operating Temperatures

[StuckeyOG]

I have a KA24DE in my S14 with OEM thermo, Mishimoto rad/cap, and Mishimoto e-fans wired to the stock cooling relays.

My coolant temps are usually between 200 degrees and 220 degrees Fahrenheit during city driving (even late last night when it cooled off it was at 205). Went to the track about a month ago and it wound up being 115 degrees out, the day of. Car was idling at 220 degrees and would slowly climb over a couple laps (I would pull off at 235 degrees but it would've kept climbing). I'm not sure if this is to be expected at those kinds of temperatures or if I need a better cooling system, an aftermarket fan controller, or something along those lines.

Basically, I'm just wondering what kind of temperatures you guys are seeing in your KAs, and under what circumstances? From what I've been able to find, I think most people see around 200 degrees Fahrenheit tops. My buddy is telling me not to worry as 200-220 degrees "isn't that hot", his reasoning stemming from the Corvette's high operating temps. He could very well be right, but I'm boosting the KA soon and want my cooling system to be up to spec. Especially since I already toasted my first KA with a slow leaking headgasket.

Thanks in advance for the help.

[corkscrew]

According to my obd2 adapter and scan tool mine is around 200-210 as well. Not sure if that's ok either so I'm posting as well for other members input lol

[KAT-PWR]

I run no thermostat in mine and I don't think I ever hit higher than 195 at the last drift even. KA-t

[StuckeyOG]

I run no thermostat in mine and I don't think I ever hit higher than 195 at the last drift even. KA-t

Thanks KAT-PWR and Corkscrew for the input.

The car is street driven quite a bit so I'd prefer to retain a thermostat if I can. The original engine that came with the car had no thermostat (although it was bc the head gasket was going) and I wasn't a fan of the long warm up times.

What kind of fans/rad are you running, if you don't mind me asking?

[pacotaco345]

When I had the KA in my car it would run around 185* cruising in Texas, that was stock radiator, thermostat and altima fans.. Cruising down the freeway it would heat up a little over 190* but I never saw 200 unless I was beating on the car. Whenever I put a Koyo in it with a 165* tstat and the same fans I distinctly remember cruising through Blythe in 112* heat with the A/C on and my car sat at 165* and the fans off. Never drifted the car with that setup but I assume it wouldn't have seen over 180*.

Not sure why your car is running so hot, have you bled the system properly? Anything obstructing the intake of the radiator? Do you know what temps your fans kick on at?

[andisan]

I would get an aftermarket fan switch and set it up to what temperature you want them on too, best thing I did and it stays at a good 190 and that's only using one fan on my Altima fans, I had problems before but it was because I had air in my system because I removed the intake to clean it.

***You might want to check what the stock cooling relay runs at what temperature. I can't remember and don't want to give you false info***

Since our cars "KA" engines run on the clutch fans and not on relays, I think the relay is for the AC unit and turns on at a high temperature if I remember correctly, Someone can correct me if I'm wrong, I don't mind ;)

[StuckeyOG]

When I had the KA in my car it would run around 185* cruising in Texas, that was stock radiator, thermostat and altima fans.. Cruising down the freeway it would heat up a little over 190* but I never saw 200 unless I was beating on the car. Whenever I put a Koyo in it with a 165* tstat and the same fans I distinctly remember cruising through Blythe in 112* heat with the A/C on and my car sat at 165* and the fans off. Never drifted the car with that setup but I assume it wouldn't have seen over 180*.

Not sure why your car is running so hot, have you bled the system properly? Anything obstructing the intake of the radiator? Do you know what temps your fans kick on at?

Honestly, I worded my concern incorrectly. Let me try again:

Cruising around the city is 195-210 degrees. With the A/C on it can climb to 220 on a hot day. If I'm driving up a steep canyon with the A/C on on a hot day, it will generally run between 220 and 230 degrees. And on the freeway, its usually between 180-190.


Since its hooked up to the OEM relays, when I have the A/C on both fans are running. I would assume they turn on at the OEM temps because they're wired to OEM relays. Upon doing some more searching, I found they turn on at 203 degrees and 212 degrees Farenheit. Which I suppose explains the temperatures that I'm seeing.

No offense intended, but I almost feel like 165 degrees is too cool. If it was strictly a track car I would consider getting a colder thermostat, but it is primarily street driven.

The system is bled properly. The radiator has a clear path, only OEM stuff in front of it such as the A/C condenser and the OEM Zenki bumper.

The more I read up on this and look into it, the more I feel as though my cooling system is actually within spec, and that I'm just over-worried. However, it would be nice to have my KA sitting between 185-215 degrees once its up to temp and being beaten on.

I guess I'll get an aftermarket fan controller (recommendations?), if that doesn't do much then I'll start saving for a Griffin/Koyo radiator and a SPAL fan setup. If anyone has any other advice to contribute, let me know!

Thanks again guys.

[StuckeyOG]

***You might want to check what the stock cooling relay runs at what temperature. I can't remember and don't want to give you false info***

Since our cars "KA" engines run on the clutch fans and not on relays, I think the relay is for the AC unit and turns on at a high temperature if I remember correctly, Someone can correct me if I'm wrong, I don't mind ;)

I thought this was the case as well, and assumed that the previous owner converted to aftermarket fans, but my pops pointed out that I did indeed have OEM electric fans because of the hi-fan and lo-fan relays. I know, I'm a rookie lol.

I looked into it more and it turns out the S14s came with electric fans stock. Low fan comes on at 203 degrees and high fan on at 212 degrees or with A/C override. I think you're right about the whole fan controller deal, what kind of switch are you running?

[pacotaco345]

Don't worry haha I'm not offended. 165 was really cold but I'd rather see my temp gauge on the edge of cold rather than hot. I feel like with a big radiator your car should run a bit cooler than it is, its probably just your fan tuning though.

I have an HKS fan controller/water temp gauge. It hooks straight up to the ECU so you don't have to run a sensor into the engine bay like all the other setups, also allows control of two fans independently. Now that I have an SR my first fan kicks on at 170 and the second comes on at 185. In hot weather the water temp seems to level off around 195 which is ideal to me. I think these controllers are discontinued but if you can find one they're a great part.

I looked into it more and it turns out the S14s came with electric fans stock. Low fan comes on at 203 degrees and high fan on at 212 degrees or with A/C override. I think you're right about the whole fan controller deal, what kind of switch are you running?
Regarding this, 240s come with the stock clutch fan, then behind the clutch fan shroud there's also a small, 2 speed electric fan. That small electric fan is used to pull air for the A/C when the car is still cold and to cool the car when the clutch fan can't keep up (which is why the temps for those relays are set so high). In other words its not meant to keep the car at operating temp, its just a precautionary thing to keep you from blowing a headgasket.

[andisan]

http://uploads.tapatalk-cdn.com/20160711/ba880fc55bd3c6d2e8d9bea2fbaf8a3b.png

That's the one I have and so far I haven't had any problems with it, had it for at least 2 years

Easy to wire and set up

There are also lots of other ones, you can look up and see which one you would like

[andisan]

Regarding this, 240s come with the stock clutch fan, then behind the clutch fan shroud there's also a small, 2 speed electric fan. That small electric fan is used to pull air for the A/C when the car is still cold and to cool the car when the clutch fan can't keep up (which is why the temps for those relays are set so high). In other words its not meant to keep the car at operating temp, its just a precautionary thing to keep you from blowing a headgasket.


That's what I figured but wanted someone else to confirm

So it looks like that's why you are running so high in temperature, you're fans aren't engaging until it's hot then if you even bring the temp down"cooling the engine" the relays kick on at a high temp that it will never bring the engine temp down past 200 because it will disengage the fans, you'll run hot all day

You need a fan controller

[StuckeyOG]

Don't worry haha I'm not offended. 165 was really cold but I'd rather see my temp gauge on the edge of cold rather than hot. I feel like with a big radiator your car should run a bit cooler than it is, its probably just your fan tuning though.

I have an HKS fan controller/water temp gauge. It hooks straight up to the ECU so you don't have to run a sensor into the engine bay like all the other setups, also allows control of two fans independently. Now that I have an SR my first fan kicks on at 170 and the second comes on at 185. In hot weather the water temp seems to level off around 195 which is ideal to me. I think these controllers are discontinued but if you can find one they're a great part.


Regarding this, 240s come with the stock clutch fan, then behind the clutch fan shroud there's also a small, 2 speed electric fan. That small electric fan is used to pull air for the A/C when the car is still cold and to cool the car when the clutch fan can't keep up (which is why the temps for those relays are set so high). In other words its not meant to keep the car at operating temp, its just a precautionary thing to keep you from blowing a headgasket.

That's what I figured but wanted someone else to confirm

So it looks like that's why you are running so high in temperature, you're fans aren't engaging until it's hot then if you even bring the temp down"cooling the engine" the relays kick on at a high temp that it will never bring the engine temp down past 200 because it will disengage the fans, you'll run hot all day

You need a fan controller



That explains so much. Seriously, thank you for clearing that up guys. I've been trying to figure the clutch/e-fan debate out with my Dad for a while now lol.

I forgot I had downloaded a copy of the FSM a while ago, low and behold it shows a crankshaft driven clutch fan. I had a feeling the stock relays were just kicking on at too high of a temperature, at least now I know why! I'll be getting a fan controller right away.

Once again, huge thanks to Andisan and Pacotaco345 for sharing their experiences, as this was really bugging me for a while. Hopefully this thread will help benefit someone else in the future.

[Kingtal0n]

200-212*F is about as hot as I would want to see in one of these old engines, for normal driving.

The more "racing" you do the more cooling equipment you will want, and a slightly lower temp around 180*F for coolant usually. It depends on how the oil temp is. A colder coolant temp is fine (160*F) if the oil temp is nice and hot (200*F~). Colder water is associated with increased wear and tear- because it might hold oil temp down with it, and running cold 'thick' oil in a hot engine is not good for the engine.

[justinbyrant]

230 degrees is way to hot, 112 where the fan kicks on is considered hot but within spec think about it this way, if the fan kicks on the car thinks its to hot, my ka was na built, oversized exhaust and intake valves, everything was port matched, sr injectors, and way advanced timing it should have ran hot and with a 185 thermostat it never crossed 190 unless something was wrong or it was over 100 degrees outside on a track day anything over 205 and I let her sit, normal 85 degree day in town and mine would never run hotter than 180, granted this was with a mishimoto radiator, and Altima fans on a new engine, if she stayed down around 160-165 the idle would act up sometimes but not bad and it only stayed that cold in the winter, all this was verified with 3 different gauges, corvettes and whatnot can run hotter because they are aluminum blocks and aluminum heads, the problem with iron blocks and aluminum heads isn't that the heat kills them its that when they cool down from getting really hot the heads cool faster than the block and they warp where they meet that's why ls engines can get away with hotter temps the whole thing cools at roughly the same speed