Always Hot!

[ItsBoostin]

Just finished putting a new turbo on the 32 everthing is all sweet there. But now it runs super hot always hovering around the 85-90deg area the car has a new waterpump new thermostat new hose's new thermo housing have just heat wrapped the dump pipe and have a beanie on the way for the turbo, even have the bonnet lifted at the back. Car does have a FMIC but there is plenty of room between it and the Radiator, radiator is in very good condition as well.

Any ideas?

Thanks

[R31Nismoid]

What radiator?

High mount turbo or low?

85-90 isn't anything overtly 'bad'.

Did you put the rear of the bonnet up @ the same time as the rest? Could try it down (i've never been convinced it helps, i never get over 75 with my rear down )

[ItsBoostin]

Radiator is factory turbo is low mount and the bonnet was up before the turbo install.

There just seems to be a super amount of hot air at the front of the engine.

[Guilt-Toy]

I had a issue with mine after a rebuild. I found that I accidently put on the wrong engine fan. The one i put on was from a R31 skyline and it was a different design to the RB25 one and it caused heating up to about 98 deg on normal running.

Also make sure you have bleed the cooling system correctly. ask if you are unsure how to do this. It is also good to do it when the front of the car is jacked up as high as you can go.

if your running thermo fans make sure they are turning the correct way also

Radiator is factory turbo is low mount and the bonnet was up before the turbo install.

There just seems to be a super amount of hot air at the front of the engine.

[blind_elk]

Like the Nismoid, I, too, am unconvinced on the ability of a raised bonnet rear to assist in cooling.

The base of the windscreen is a high pressure region, which is how air gets pushed into the ventilation / heater system. I believe it is also why the old-school GroupA Fords / Holdens had that reverse bonnet scoop to feed the carburetors.

Air moves from regions of high pressure to regions of low pressure. The high pressure air at the base of the windscreen will be pushed into the engine bay through the raised rear edge, increasing the pressure inside the engine bay. This will reduce the pressure differential between the front of the car and the engine bay, limiting air being able to pass through the radiator. And if air doesn't pass through the radiator, no cooling takes place.

Put the bonnet rear back down (the way Nissan designed it).

[femno]

+1 for incorrectly bled cooling system

The bonnet has nothing to do with it.

[ItsBoostin]

Thanks. I guess I'll put the bonnet back down and re-bleed the system. Might aswell ask what the "correct" way to bleed the system while I'm at it.

[Jap_Muscle]

i am also having this problem and decided to hpc coat everything on the exhaust side...to bring engine temps down

[R31Nismoid]

You are running a highmount without a heatshield - the two things (whilst related in terms of heat) are totally different in terms of what is causing vs the fix

[GDZ-14R]

Is that temp range out of the ordinary anyways?? My stock 34 GTR runs 82-87 regularly, and up to 90 with the aircon on (MFD readings).

[R31Nismoid]

That is normal for a R34 GTR - they run a bit hotter than R32/R33's for whatever reason

[Wacky Dee]

that's because R34 (GTR/GTT) thermostat starts opening at 82c and is fully open at 85c (or 86 can't remember exactly now) whereas the R32/33 starts opening at 76.5c I think it's an emissions thing, R34 engines like a bit more heat.

To bleed properly try this .. get a 2l coke bottle (clean it out obviously) and cut the bottom off. Stick it inside the radiator opening and seal the area properly so that coolant can't escape. Poor the coolant in and overfill so that there's like 10-15cm of coolant in the bottle ABOVE the radiator cap. Run the car like this for 20-30 mins. You'll see an absolute insane shitload of air bubbles come out through the coolant in the bottle as the car warms up. I couldn't believe the amount of air that came out when I used this method. Probably about 20x more than I got out using the engine bleed screws.

If it's still overheating make sure your fan shroud is on properly .. without a shroud it will always overheat no matter what.

[allthewaytotheskyline]

my 34 gtt modded reads about 87-91.

[geraus]

mine reads at 82 with an ISC alloy radiator, even on hot and when im giving it a hard time, also my screamerpipe is hanging out with no shields on dump pipes and turbo heatshield is offl, If i chuck back on my turbo heatshield would it make a diffrence?

[battery]

my old rb20 would stay rock solid between 78-82c highest i got it was 87c

the rb25 i have now is all over the place it will get up to 90c after 5 mins of idling in hot weather usually idles around 84ish but when i hit the freeway in the morning and give it a bit in 2nd/3rd out of the off ramp it will go down to 74c... then back up to 78c while cruising in 5th at 3000rpm.

i think the water pump is on the way out, i get a little whine on idle so that's probably the cause.

[W0rp3D]

To bleed properly try this .. get a 2l coke bottle (clean it out obviously) and cut the bottom off. Stick it inside the radiator opening and seal the area properly so that coolant can't escape.

Best way to seal it is to put some electrical tape on the thread where the bottle cap goes, then you just have to push it into the radiator and twist it and it will seal as well as staying there with out having to hold it.

[ItsBoostin]

Sorry to bring up my old post but i still cant get my temp down ive bleed the system more then 5 times using all the suggested ways but it still sits at 90deg at idle and when i give it a bit the temp hit 100+ and takes over 20min to come back down. Realished tonight that my fan clutch/hub is always on and working??

Really over this so any help is appreciated.

[GTScotT]

Like the Nismoid, I, too, am unconvinced on the ability of a raised bonnet rear to assist in cooling.

direct from one of cams highest regarded officials, the windscreen is actually the highest pressure point of the cars body. raising the rear of the bonnet will force air into it at speed and not allow the hot air to exit the engine bay as efficiently as designed from factory. this is Fact.

as for temps of 85-90, I personally think this is fine. I once had an NXR that would not turn the rad fans on till 105 deg, keep in mind there are only electric fans on those cars.

[ssxRicho]

the clutch fan should be pretty 'stiff'. if you spin it by hand (while the car is off ) it should stop pretty quick.

if it doesnt stop quickly, the fluid in the fan is most likely gone. so wen the prop spins the fan doesnt spin with it all the time.

so it could be moving, but not fast enough.

also the radiator could be clogged. it will flow, but not fast enough.

i went through this just a little while ago.

swapped the fan over as its was pretty much free spinning, then found the radiator channels to be blocked, to the point where there was

about 2-3mm for the water to flow.

also with the new turbo, the water lines? used the standard lines? the bango bolt pin hole could be blocked a little?

Sorry to bring up my old post but i still cant get my temp down ive bleed the system more then 5 times using all the suggested ways but it still sits at 90deg at idle and when i give it a bit the temp hit 100+ and takes over 20min to come back down. Realished tonight that my fan clutch/hub is always on and working??

Really over this so any help is appreciated.

[l0WRB]

Id try a new radiator man thats 2 hot i think.