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hay guys and gals

Well last night I was on the Thursday night cruise going down Old Pac and I looked down at my Temp Gauge and it was just under the 2 dashes at the top of the gauge that mean "hay, I’m f***ing HOT!", now I was fanging it pretty hard and I was sitting on some high revs on the inclines, but I have done old pac a million times and I don’t think I have ever seen the gauge go up so high.

My theories are

a) it always goes that high but I'm always concentrating on the road that I have never noticed (and therefore my question is, should my temp gauge fluctuate that much at high revs?...or is this really a problem?)

b) my thermo stat isn’t opening up at high temps or only opening up slightly (but in saying that, once I slow down and let it cruise at low revs, 2 grand, it cools down fairly quickly (travelling at about 80kms) which means that the radiator is doing its job....right?)

c) I need new coolant? (but my mec said that shouldn’t really make a diff) I’m soo confused :S

d)air pocket? (but what’s the likely hood of that? and if so, why would it happen?)

Now, after taking it easy and letting the engine cool down to normal, I continued down old pac, not as hard as I had been, but still fairly hard to see if I could get the temp up again but I had no problems......

I don’t know what to doo!!

help :P

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Best bet would be to do a coolant flush and new OEM thermostat. Sounds like its sticking.

Next id be getting the radiator core checked out. But start of cheap to expensive :P

Does your overflow have coolant in it? Could also be a dodgy Radiator cap.

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Best bet would be to do a coolant flush and new OEM thermostat. Sounds like its sticking.

Next id be getting the radiator core checked out. But start of cheap to expensive :P

Does your overflow have coolant in it? Could also be a dodgy Radiator cap.

yea Ive been told to do a flush - new OEM thermostat....is that going to be expensive?

yea over flow is at the right level check that as soon as i pulled over

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If the temp drops while cruzing at a steady speed with lots of air flowing into the radiator but goes up while standing or low speed, its your clutch fan most likely.

If its generally high all the time regardless its most likely the thermostat, crap blocking the radiator air flow or sludge blocking the radiator water flow.

If its losing water it may be the radiator cap, water leak from a split hose or water pump or a head gasket.

Head gaskets tend to let out steam out of the exhaust and/or water into the oil in which case your oil will turn milky white.

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I'm having the same issue as described.

I did 2 laps on track and both oil and water temps rose to 115-120degrees in no time. I backed off and let it cool down, which it did, but then rose again very quickly once I started another hot lap.

I checked and bled the coolant in the pits and then went back out but it still hit those temperatures again in just over a lap.

I went to get the radiator flow tested but was told they couldn't do much with it? Hmm

My mechanic said it's either the radiator or the clutch fan but he doesn't have a spare clutch fan to test. Do they cost a lot?

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If the temp drops while cruzing at a steady speed with lots of air flowing into the radiator but goes up while standing or low speed, its your clutch fan most likely.

If its generally high all the time regardless its most likely the thermostat, crap blocking the radiator air flow or sludge blocking the radiator water flow.

If its losing water it may be the radiator cap, water leak from a split hose or water pump or a head gasket.

Head gaskets tend to let out steam out of the exhaust and/or water into the oil in which case your oil will turn milky white.

i like your thinking but my symptoms don't match any of these, and the steam out of the exhaust i wouldn't know about.....its only gone up that once and it didn't go up again even when i was going fairly hard at it (not quite as hard as before when the temp did go up) and the temp stays the same when its idle or low speed (when air isn't flowing through the radiator)

:P any other ideas GTRPSI? could it just have been a freak thing like an air pocket or simply i was just driving it to hard for to long and the stock cooling just wasn't enough?

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I wouldn't be taking any chances if I were you. My brother hit a small wallaby in his mazda .. the broken grill plastic punctured the radiator so it started leaking coolant. Car overheated once or twice but was promptly stopped and let cool down / water refilled. Anyway, 1 day of that and the engine blew up .. $10k in damage.

If I were you I'd replace the thermostat as it's cheap and get the radiator flushed and flow tested at the very least ..then take it for another sping up the same road. Engine overheating is NOT normal and not a freak 'one off'.

Also, I'd recommend installing a couple of decent gauges .. the autogauge water termp gauge is about $80 and easy to install.

Edited by Delta Force
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:D any other ideas GTRPSI? could it just have been a freak thing like an air pocket or simply i was just driving it to hard for to long and the stock cooling just wasn't enough?

Tell you what id be doing if im unsure.

Make sure your fan belt is reasonably tight and not slipping.

Then dont muck around, change the thermostat, ive seen them get sticky and need heaps of heat to wake them up in some cars.

If you want to be extra cautious take your radiator out at the same time, turn it upside down and run a garden hose in it to reverse flush it. You could also hose out and obstructions in the cooling fin area while its out.

Bleed all the air out when finished.

At least do the thermostat and bleeding if your too lazy to pull the radiator out. It will only cost you a thermo and some coolant, nice and cheap to do.

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I wouldn't be taking any chances if I were you. My brother hit a small wallaby in his mazda .. the broken grill plastic punctured the radiator so it started leaking coolant. Car overheated once or twice but was promptly stopped and let cool down / water refilled. Anyway, 1 day of that and the engine blew up .. $10k in damage.

If I were you I'd replace the thermostat as it's cheap and get the radiator flushed and flow tested at the very least ..then take it for another sping up the same road. Engine overheating is NOT normal and not a freak 'one off'.

Also, I'd recommend installing a couple of decent gauges .. the autogauge water termp gauge is about $80 and easy to install.

Tell you what id be doing if im unsure.

Make sure your fan belt is reasonably tight and not slipping.

Then dont muck around, change the thermostat, ive seen them get sticky and need heaps of heat to wake them up in some cars.

If you want to be extra cautious take your radiator out at the same time, turn it upside down and run a garden hose in it to reverse flush it. You could also hose out and obstructions in the cooling fin area while its out.

Bleed all the air out when finished.

At least do the thermostat and bleeding if your too lazy to pull the radiator out. It will only cost you a thermo and some coolant, nice and cheap to do.

Thanx heaps guys - i will do all of that - new stat - flush radiator and get a flow test. im also likeing the word cheap because i have had a few things i have had to fix up and im a little low on cash, so how much are we talking? and dw i wont hold you to it - it would just be nice to have a number in my head so i dont get a shock :D

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Get a non genuine thermo and radiator fluid, probably $20 for the thermo if you can find one and less than $20 for some coolant, less than $10 for some blue silastic all the rest is spanner work. Less than $50...most likely $40 should cover it.

Go genuine Nissan thermo and fluid and id recommend seeing a bank manager first. :D

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Alrighty, Im going to cover all my bases here - im going to buy a new thermostat from just jap - http://www.justjap.com/store/product.php?p...at=0&page=1 - then im going to buy a flush and flush my system out.....obviously new coolant...and if funds allow it i wouldnt mind getting that flow test done....

could it be posssible that my water pump or wtvr isnt circulating the water around quick enough? ergo its worn out and just not pumping at the right rate, this theory isntead of there being a blockage thats stopping the flow offcause....

also i have been driving all day and been watching my temp gauge like a hork...no change! and im going to the snow tomorrow and im swaping cars with my mum - she has a 4wd so i needs it - and i wont be able to do it for a week and since driving around hasnt effected the temp hopefully it should be alright... ill get her to keep an eye on it tho...

arggg cars cars cars

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Ill still put my money on a sticking thermo, but a blocked radiator water and or air side can make problems too...you would be shocked by how much crap can be caught inside the cooling fin area and in the water passages.

Seen heaps of crap come out of some radiators when reverse flushed, if you do it a few times should be better than it was.

Id worry about a water pump impeller failure after following the above tips...some how i doubt it though.

Thermo should be changed every now and then, best done before it overheats or under heats, they do fail.

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If its the water pump its gonna bee annoying for you if its located like the R33, then your gonna have to take everything out to get to it.

Best bet just take it to the mechanic, unless your experienced with all that stuff.

Edited by Djshevy
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go and speak to frank at hills radiators, get a flush and check over the radiator

haha that's a good idea...go to a place that actually specializes in cooling :P - i think i might just do that when i get back from the snow!! - let you all know how i go!

thanx for all the advice!

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  • 2 weeks later...

so how'd you go and how was the snow, yo ? (Mad rhymes there...)

I just plugged in a consult cable today and noticed my ECU saying water temp rose to 96 degrees at some point and that's in today's freezing weather in Syd... so I'm curious if/which of the above helped you out. I'm gonna start with thermostat/new coolant as that's the cheapest thing to do.

Did you get your radiator 'reverse flushed' etc ?

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