rb25det getting hot.

[smoked240]

I have been having this problem for quite awhile. While driving normal my temp sits at 90c,that's with dual fans and the heat on. If I turn either off it will go up a lot. I have a n1 water pump and nismo thermostat. The plans I have to fix it are,oil cooler,kouki front end,maybe better fans. Is there any good oil cooler kits I can get? I would just get parts and hook it up,but I don't have much spare time to do so. Or I was thinking of cutting my bumper cover up. My cover blocks all the air that can go to the radiator,that's why I think the kouki would help a lot being it has a grill. You guys have any insight on the issue? Thanks!
It's in a s13.

[Boostin240sx]

I have 3 electric fans (2 pushers, 1 puller), still have AC, stock water pump and thermostat, 89-90 bumper with the slots cut out. Under normal driving in 90 - 100 degree F heat the highest I see is 84 degree C.

[Zacho]

The n1 water pump is designed to not cavitate at constant high rpm and still flow water. In stop/go traffic it does not fair so well. So Im sure that is not helping.

I also would be 100% sure you have bled the cooling system well.


If I turn either off it will go up a lot. I have a n1 water pump and nismo thermostat.

Just a tip, remove the nismo t-stat if you aren't tuned for it. It runs the engine cooler(when you solve your cooling problem)and will leave it in the last block of cold enrichment on stock maps.

[smoked240]

The n1 water pump is designed to not cavitate at constant high rpm and still flow water. In stop/go traffic it does not fair so well. So Im sure that is not helping.

I also would be 100% sure you have bled the cooling system well.




Just a tip, remove the nismo t-stat if you aren't tuned for it. It runs the engine cooler(when you solve your cooling problem)and will leave it in the last block of cold enrichment on stock maps.

I have flushed my cooling system 5 times now and blead it every time so I don't think its that. I would remove the thermstat,but I don't have the old one,I will order one and try that. I could always just remove it and run it without for a day to see if it helps.

[ch1873857]

my last rb25 overheated a lot. most of my water jackets and coolant pipes were rusted out. coolant looked like mud. i have also heard that n1 pumps are no good for daily driving. guess i would recommend a stock water pump . make sure your coolant looks like coolant. and most importantly, make sure your system is bled properly. obviously if you have heat that shouldnt be an issue. if you can get some kind of fan shroud and coolant ducting (those cheap sheet metal shits will do) . an oil cooler will not solve your problem. i believe your overheating simply because there is not enough air flow. a proper fan shroud would probably do wonders for you. i plan to fabricate some brackets that set my core further away from the engine to provide more room for puller fans and an aluminum shroud and will cut back on heatsoak.

[smoked240]

my last rb25 overheated a lot. most of my water jackets and coolant pipes were rusted out. coolant looked like mud. i have also heard that n1 pumps are no good for daily driving. guess i would recommend a stock water pump . make sure your coolant looks like coolant. and most importantly, make sure your system is bled properly. obviously if you have heat that shouldnt be an issue. if you can get some kind of fan shroud and coolant ducting (those cheap sheet metal shits will do) . an oil cooler will not solve your problem. i believe your overheating simply because there is not enough air flow. a proper fan shroud would probably do wonders for you. i plan to fabricate some brackets that set my core further away from the engine to provide more room for puller fans and an aluminum shroud and will cut back on heatsoak.

Oh yeah I know what you mean. My coolant was rusty for awhile,that's why I flushed it so much. That is exactly what im thinking and know. When I removed my bumper cover and drove it,temps dropped from 100c to 70c after driving. I think the kouki front would help a lot with proper ducting and a fan shroud.