overheating problem r32 gtr

[mistercrow]

hey guys.

i have a problem of overheating that only occurs when i boost the car.

Normal driving days, without too much boost, i can drive around, traffic, highway city and the gauge always stays normal running temp. When i turn off the car i hear bubbling coolant in overflow once in a while.

its not the same when i use the car for its power. when i start to boost the car, the temp usually starts to grow
and stays at the 3/4 mark on gauge and that, after 1 second gear pull, give it two three mins the coolant is boiling.

the car has been stored for 6 months without any issues last year, and i have started to roll the car its been around 1500 kms, without too much abuse.

i have replaced the termostat, replace the rad cap with gates 1.3 bar caps, tried 2 of em still overheats.
starting to think it might be the head gasket starting to fade away.

what i did up to date:

any tips would be welcome.

- i havent used a pressure test,
- the coolant doesnt bubble in rad cap when the cap is off and engine running
- no oil in coolant.
- no coolant in oil.
- no white smoke coming out of exaust on idle, boosting, and normal load.

thanks i need some help.

[bobbo]

Mods?
Might be a circulation issue.

[caliber676]

Pressure testing and leak testing is going to be your best bets

[mistercrow]

460 whp, r32 gtr rb26 full built with 2 rebuilt gt2860-7s. cooling mods are mishimoto rad, 2 12 inch mishimotto fans,
stock termostat. 1.3 bar gates cap.

can a slow coolant leak cause overheating under boost?

[Micho]

I had similar problems with my KA24, replacing the water pump seemed to do the trick.

[Skym]

Small headgasket leak usually shows up after a long drive.

If used a higher pressure radiator cap on stock radiator, can blow waterpump seals, radiator hoses, headgasket, etc. From what I understand, a higher pressure radiator cap is designed for thicker radiators where the pressure can drop and is done with upgraded waterplugs, metal headgasket, etc. But you have upgraded the radiator, so that doesn't apply in this case.

Also a air separation tank would help (Greedy / Trust brand or similar), as the stock waterpump can create bubbles at higher rpm (cavitation) which can clog the tubes in radiator and cause overheating. Or radiator is blocked (does happen) and the end tanks need to be removed to be cleaned out (stock, some aftermarket radiators).

I agree with changing waterpump, as sometimes the blades can corrode away and cause overheating problems. Usually waterpump leaks or makes a weird noise (what happened on my car) when it fails.

[mistercrow]

alright i will order a new water pump, anyone got n1 part number or stock does the job?
will put a pressure test on it also monday. thanks for the help guys.

2 questions

1 is there a way to diagnos a head gasket without tearing the block appart? i dont want to take 20 hours to rebuild the engine again
to get to the head gasket and be like ****, that wasnt it.

2:what is stock rad cap pressure?

[Black BNR32]

460 whp, r32 gtr rb26 full built with 2 rebuilt gt2860-7s. cooling mods are mishimoto rad, 2 12 inch mishimotto fans,
stock termostat. 1.3 bar gates cap.

can a slow coolant leak cause overheating under boost?

yes..

[Black BNR32]

1 is there a way to diagnos a head gasket without tearing the block appart? ?

http://www.importtuner.com/tech/impp_1108_blown_head_gasket_diagnostic/

[mistercrow]

Thanks guys for all the help i will try to do a leak test before anything then replacing thr water pump, if those 2 dont work out ill go for head gasket.. I hope i wont have to get there.

[mistercrow]

Is it true r32 gtrs use a 0.9 bar cap instead of 1.3? If so ill try oem cap instead of jobber one and see if problem persists.

[steveo1502]

overheating problem r32 gtr

Oem is .9 bar, sounds typical for gtr with electric fans, that's why a lot of people go back to the stock clutch fan, way better cooling, first thing I would do is get some spal fans, those mishimoto fans are crap, I run the same ones, I kinda have issues with overheating with my ac on, but recently I switched the control to my haltech, so when the ac is on the fan comes on, it's much better now, plus I had a autometer temp gauge/controler that used to turn on the fan at 85, would go off at 84, and back on at 85... Was stupid, the haltech now comes on at 85, off at 81, it's way better.

[steveo1502]

What turns on your fans?

[mistercrow]

Hey guys, ill put back stock clutch fan, brand new oem water pump and rad cap ( if someone can get me both part numbers id love it). Do you have to put the shrowd also or just fan? Both 12 inch fans were ran directly to an indipendant circuit that runs with key on, getting signal from a/c, since it got deleted. I run power fc with djetro, the car doesnt run lean at all, got tuned a month ago. Wideband shows 11.9-12.5 full throttle and idling around 13.8-14.1. Car has tomei metal headgasket resurfaced cylinder head, poncams, tomei springs, wiseco pistons, k1 rods and fully balenced crank assembly with crank collar, nitto oil pump. Everything is kinda overkill for the power, but i want it to be reliable over anything else. Only the cooling system has issues now and it pisses me off!

[steveo1502]

So when the key is on , the fan is on? What u mean signal from ac?