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hey guys

now that we have hot days as soon as its 35+ outside with or without the a/c on my car overheats this only happens when im driving but when i stop the temp starts to drop but takes awile and my overflow bottle was boiling with coolant and over filling? would it be the radiator cap? not holding pressure because it was making air noises when i popped the bonnet up

thanks ppl

Edited by Jsikalias
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im gonna go with radiator cap not holding pressure.

run the car up to temp, and with the cap on, squeeze the top rad hose, there should be pressure in the hose during normal operation. If there is not then the cap is not sealing, so the coolant will boil. (the pressure raises the boiling point of the water/coolant)

I had the same problem a couple of weeks ago, turns out one of the big fittings on my intake manifold has rusted pretty bad due to a previous owners not using antifreeze, which in turn blocked the radiator and would cause the car to overheat, i would suggest taking out your radiator and get it tested and cleaned.

http://www.skylinesaustralia.com/forums/Co...-O-t196137.html

i dont think it is your pump man. the pump is basically fins on a shaft that push water around. the only thing that goes in the pump is seals and bearings and i doubt that the seals could leak enough coolant to cause that!
If previous owners haven't used coolant treatment (and the Japs are notorious for not doing so), the fins rot away. Under load, the rotted fins cannot circulate the coolant; the engine produces more heat that cannot be removed because the coolant isn't being circulated. At idle, the remaining bits of fin can circulated the water, so it tends to cool a bit.

ive actually got the exact same prob at the moment water pump is less than 5000ks old changed it when i dit the timing belt ect ect . my car has never overheated at all or even come close in the time ive owned it i run good coolent .

the other day 40+ in adelaide going up the hills first thing the aircon cut out ive since found if ya car is getting to hot the ecu cuts the air con r33.

temp gauge went to 3/4 and i pulled over water was pissing out the overflow tank onto the ground we let it cool down and started the car and topped up the water turned around and headed home as it was now going down the hills and hardly any load the needle went back to half and the air con was ok again .

next day thought i would take it thru the hills closer to home and the same thing happened again normal driving even in the hot weather with the air con on its fine its only when ya hit the hills i have trouble.

will put in a new themrostat this week and a new cap and see how that goes .

the rad looks very clean as far as you can see but will get it cleaned out if the thermostat and cap dont help .

let me know what fixers yours if ya find the prob

cheers dean

to flush the radiator u dont neeed to remove it. just d/c the top hose and then the bottom hose. put a hose in the top and flush away. after that flush the engine by sticking the hose into the intake (top hose) and allowiing the watr to come out the bottom.

if u get brown water and crap coming out, thats the issue for ocer heating. rusted dfins and crap in the radiator (rust) that i causing yor issues. but also after doing this getyour cooling system pressure tested.

in my old 33, sme thing happened. flushed radiator, had it checked and still same thing. pressure tested the system found a small leak from a hose that was 10cm long but enough that it was leaking fluid at temp and causing the overheat

yeah dude i had same prob in my 32 when the new motor went in they didnt flush the old rad and engine, the radiator just acted as a huge collection for crap out of the engine it was so blocked ,cleaned with kero and tried as hard as i could to over heat it and it wouldnt

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