Rb26 Rising Temp - Advice

[aleaspeed]

Just completed a re-build:

JE 87mm pistons

Tomei OGK - 1.2mm

ARP Head studs

Cosworth Bearings - Std

Tomei Poncams - 260/260

Apexi PFC - D Jetro

Koyo 4 core Radiator

N1 oil pump

Mishimoto 62c Thermostat

GT2860-5 Turbos

Mines Titanium DP

3.5" SS Jasma Exhaust

Car runs well and maintains water temp in the 70s and oil temp in the 80s when driving.

Problem is when idling for more than 10mins, water temp rises to 90c+. If the car is parked soon after, about 200ml of coolant flows out of the expansion tank.

Advice?

[eightsixboy]

Are you running the standard viscous fan?

[aleaspeed]

Yes. Standard viscous.

[R31Nismoid]

4-core radiator probably not flowing enough @ idle.

[aleaspeed]

Would an N1 water pump help?

[paulr33]

you might have a basic water pump issue or some sort of flow issue

90 isnt that bad, but it shouldnt move past 90

ask the engine builder?

the n1 water pump flows less at idle vs stock as its designed for high end RPM high flow

so at idle, it will actually be outperformed by the std water pump in terms of flow

when did this start? since the radiator change?

check the basics etc

[R31Nismoid]

Would an N1 water pump help?

not really.

You've gone a put a part in thats not fit for the application - a 4-core rad.

As you've stated it's perfectly fine when driving, and it will be... Or more importantly track - which is what i'll guess it's designed for. Not street.

I could be wrong, but all bets point to the rad as the issue.

You might have not bled it correctly or something and have air lock/bubbles. But i doubt it.

[aleaspeed]

I built the engine myself and it definitely goes past 90, but if I keep the revs up above 2k, it drops slightly.

The problem started after the re-build which is the same time I installed the new rad.

Already bled the system twice. No change.

[UWISSH!]

Is it a 53 mm koyo radiator? If it is I have the same on my r33 gtr

I have never had a problem like this, normal driving temp is at 66 deg n when at idle in traffic it may only move 1 or 2 degrees

[aleaspeed]

Yes it is the 53mm one.

[eightsixboy]

Does sound weird, I would replace the water pump as it sounds like a flow issue. Cant imagine there been an issue with the rad.

[battery]

I had the exact same problem, was fine when moving but hit the roof on idle..

turned out to be an air leak in the heater hoses behind the block....

[KiwiRS4T]

Why is it idling for ten minutes? Turn it off.

[zebra]

You have a 62 deg thermostat but the temps are in the 70s when driving.

Something seriously wrong there...and why so cold?

even 70 degrees is too cold for a production engine, should be up near 80

[KiwiRS4T]

Thermostat only determines when the water starts circulating. Once it is open it has no effect on max temps (only minumum temps in a very cold climate). Stock would be better as 70deg is not hot enough. Have you got a shroud for your fan? Fan doesn't do much without one.

[JonnoHR31]

also thermostat is in the bottom hose (coldest point), temp sender is in the top hose (hottest point)

[N1GTR]

Did this ever get fixed?