Cooling Issues - Please Help!

[Blue32]

Guys,

Took my GTR out to Mallala on the weekend and found that after a couple of hard laps the water temp was sky rocketing up to a maximum of 119 degrees!!! Having trouble understanding why it has gone so high with the cooling hardware I am running:

R34 RB26

Apexi big aluminium radiator

Nismo uprated radiator cap

standard viscous fan / shroud

Carbon full length UAS air guide

The car had no pinging at all (max 34 knock value on the d-jetro pwr fc), the oil temp thanks to ARC coolers went no higher than 80 degrees, and there are no leaks etc in the cooling system. I found under full noise the temp was increasing 1 degree every 10 or so seconds - and once I backed off to drive around and cool it down it took ages to get down to under 100 degrees. This temp is verified by 3 seperate sources so I believe I can discount gauge error (pwr fc / dash temp gauge and defi water temp gauge all within +-3 degrees)

I thought for one that the R34 runs a N1 pump on it, and the car behaves normally on the road with normal operating temp being 89 - 90 degrees although I believe this to be a bit high. Do these symptoms sound normal for GTR's on the track with similar mods/ hp to mine, or do I have an issue somewhere else. Looking for guidance as to fixing this from those with experience on the track with GTR's please, although come to think of it any help greatly appreciated!!!!!

Blue32

[ferni]

It does sound wierd that you are getting water temps of nearly 120 but oil temps of only 80. Normally they would be much closer since they both come from the same hot engine.... Only thing i can think of is ducting, need more air flowing through the radiator, maybe you have a big front mount in the way? WHere is your oil cooler located? Have you bleed your water system? no air?

[Beer Baron]

something is seriously wrong with your cooling system. on the street yout temp should be between 80-85 max for water temp. 119 is nuts there would be pockets of it boiling for sure by then. start with a flush, and bleed. check thermostat operation. that should be a good start.

[ferni]

something is seriously wrong with your cooling system. on the street yout temp should be between 80-85 max for water temp. 119 is nuts there would be pockets of it boiling for sure by then. start with a flush, and bleed. check thermostat operation. that should be a good start.

Thats a good point, make sure your thermostat is opening, always the simple things.

[Blue32]

Thanks guys - I'll start with a thermostat change and go from there. The temp on the street today with ambient temps around 25deg was 89-90 without a/c! Gotta be something wrong with the thermostat I reckon. How do the GTR water temps go on the track normally? Maybe we could post up our experiences with water temps at the track vs ambient air temp on the day, cooling system mods, and power the car is producing? Then we could all easily have a benchmark to check against and beable to tell if the cooling system is doing its job properly??

Use this as a template if you like

Car:

Power:

Cooling system mods:

Water temp on street:

Water Temp on track (incl ambient temp):

[gtr660hp]

CAR: 1990 R32 GTR

POWER: 350awkw

Cooling System: PWR213 radiator - cant remember thickness with twin thermo fans

Water temp street:80

Water temp track :95 highest ever after 15 laps of national QR track (ambient 32-track 48)

Oil temp : 100 and stable during 15 laps national track QR edit -forget to mention Greddy oil cooler

Edited October 12, 2006 by gtr660hp

[Beer Baron]

no need to bin it straight away, put it in a bucket of hot water with a themometer and slowly add boiling water till you see the thing fully open, then note the temp. check the workshop manual and see if it's on target (should be around 78 degrees or there abouts).

my GTR

270kw atw

stock radiator, stock thermostat

massive Greddy oil cooler ducted in the passenger side duct

water temp on street always between 78 and 82 even when hot outside, or punishing it.

on track never above 90.

oil temp varies a bit but on the street it's mostly around 80-85, sometimes up as high as 90 on the track it's been as high as 105, but water temp still faily stable.

also do you have a massive thick intercooler? if so that will be hurting your radiator performance badly.

[Duncan]

and like it was said earlier, bleed the cooling system, there is a valve on the plenum, open it start the car and let it run until water bubbles out of the bleeder, then close it back up again.

[Roy]

Yeh, do the basics. Remove the radiator and give it the pros to give it a flush. Even then if the car is new to you it may not hurt to put a radiator flush through the engine and then top it all up with a good coolant.

Never mix brands or types of coolant...if your not sure whats in there then dump it all and start again.

The bleed the thing properly as Duncan suggested (I think thats all it is)

Does your aftermarket radiator have a shroud on it? Is it as well sealed as a std radiator to the supprot panel etc

[Blue32]

Removed the radiator and sorted out my cooling issue on the weekend! It was a partly blocked radiator - containing calcium flakes which kinda look like rust flakes. Reverse flushed the radiator and in the end after I machined up an adapter to put the garden hose and the air compressor on the bottom hose, extracted some 2 or 3 table spoons of calcium build up. On initial removal, ran the garden hose through the radiator and the flow was pretty slow compared to after the flush out. Also completely flushed the engine using my hose and compressed air tool and found more within the engine. Also the thermostat in the car was a 65 degree one instead of the 76.5 factory nissan one. So now the car has a flushed system, with some tectalloy flush solution and water (until the weekend when I will reverse flush it again), a new genuine nissan thermostat and a new trust 1.3 bar radiator cap! Temps on the street today with a 28 degree ambient temp was 80-81 with the aircon on!!!!!!! Previously last week under same ambient conditions I was seeing 95-97 degrees.......... Calcium flakes due to previous owner mixing coolants - a lesson to be learnt for everyone on this one!

[Neil]

Just to add an important note about bleeding the system,,,Turn the heater on full hot so you bleed all the air out of the heaters system as well.

Neil.