Coolant Overflow Bottle Overflowing

[R34GTFOUR]

Why do you say that?

The car does not blow white smoke, it does not use water, there is no oil in the water, there is no water in the oil and the car runs perfect! i dont have any of those issues.

a car can still have a blown headgasket without any of those symptoms. Does the coolant smell like exhaust at all? Not saying its defiantely a headgasket

From those symptoms i would of thought a stuffed radiator cap, purely because it fits all your problems. A radiator cap that isnt sealing properly, will send alot of coolant to you overflow bottle, it will make you hoses feel soft since its not holding pressure, and it wont allow the cooling system to work properly since it relies on pressure.

Car cooling systems are pretty simple, so it shouldnt be hard to figure out the problem. Check the thermostat aswell, even if it was a genuine nissan item

[nizmo_freek]

a car can still have a blown headgasket without any of those symptoms. Does the coolant smell like exhaust at all? Not saying its defiantely a headgasket

From those symptoms i would of thought a stuffed radiator cap, purely because it fits all your problems. A radiator cap that isnt sealing properly, will send alot of coolant to you overflow bottle, it will make you hoses feel soft since its not holding pressure, and it wont allow the cooling system to work properly since it relies on pressure.

Car cooling systems are pretty simple, so it shouldnt be hard to figure out the problem. Check the thermostat aswell, even if it was a genuine nissan item

As i said before, i had replaced the radiator cap with a brand new one and it didnt change anything.

In my opinion it must be the thermostat, as i explained before the thermostat didnt open up today when i was filling the cae up even when the car was sitting at full temp for about 10mins, if it was working properly the thermostat would have opened and sucked through some of the coolant which would make the bottom radiator hose hot aswell, but the coolant level stayed pretty much the same and the bottom pipe never got hot at all, hence the thermostat not opening and letting water through, which would be causing my overheating problems.

Any more advice/ideas would be great

Edited December 17, 2007 by nizmo_freek

[MBS206]

Or the motor didn't have any water in it, to heat up, to get the thermo to open...

If the thermo is stuck shut, the pipe that flows from pump to thermo will go rock hard.

And if you take the radiator cap off, let it warm up, and then turn it off, it'll normally spew coolant back out (Actually EJECT IT outta the cap opening)

[r32sky_line]

Try taking the thermostat out and see if your system pressurisers

[nizmo_freek]

Or the motor didn't have any water in it, to heat up, to get the thermo to open...

If the thermo is stuck shut, the pipe that flows from pump to thermo will go rock hard.

And if you take the radiator cap off, let it warm up, and then turn it off, it'll normally spew coolant back out (Actually EJECT IT outta the cap opening)

I filled the motor/radiator up with coolant and left the radiator cap off then started the car and let the car idle, it was idling for about 20mins or more and the thermo never open, the coolant was very hot tho and the stock temp gauge was showing half, i turned the heater on aswell to get some water pumping around but the heater wouldnt even pump out any heat, just cold air.

I will take out the thermo tonight and chuck it in some boiling water to see if it opens or not.

Cheers

Edited December 17, 2007 by nizmo_freek

[nizmo_freek]

Well problem fixed

I took the thermo out yesterday and tested it in boiling water, it opened up fine, so put it back in, filled the car while it was running with the radaitor cap off, thermostat still wouldnt open up and the heater wouldnt pump out heat after about 30mins of idling, so put radiator cap back on and went for a quiet drive, the heater started working after about 30sec-1min of driving so drove for a bit longer, stopped and checked in the engine bay, the radiator pipe from the thermo housing was nice and hot and both raditor pipes were pressurised.

So everything works perfect now,the new 58mm alloy radiator obviously works really well as water temp sits about 1mm underneath the half way mark on the gauge even when giving it a "thrash", car runs perfect and the overflow bottle never gets above the MAX mark.

I will plug in my Power FC in the weekend and see what temp its running

Cheers for all the help guys!!!

[Paulie C]

So this is the same thing that is happening to me right now last week took the gf to work got home and heard gurgling/bubbling sound from the engine, full overflow bottle of coolant Shiiiiiiiiiiiiiiiiiiiiiiiiit!!!!!!!!!!!!!!!! then 30 mins later coolant back to normal level in overflow. Rad full of water, no blown head gasket symptoms.

today went to osbourne park on the way back about 10mins from home, saw the temp gauge was at 85% JESUS CHRIST! whack the heater on, managed to get the temp down a bit, put my hand in front of the vents and wasn't very hot, heater was reading 31 degrees.

Got it home,checked engine, same symptoms as previous

Hopefully it is a thermostat or radiator needs cleaning or replacement. Nice shiny new aftermarket radiator here i come

If it is a new rad anyone recommend a brand nismo, PWR, koyo whatever man

[Dose Pipe Sutututu]

Koyo, $560 delivered new.

I went for "ling long" as a quick fix, $135 delivered. Will see how it holds up next track day

[Dan_J]

im having similar problems atm so i'm just gonna place mark my post here until i have time to post up in full

is that rad cap ment to be 100% percent sealed or can it have a few drops come out while its warming up with the overflow hose pulled off ?

[Dose Pipe Sutututu]

The radiator cap will allow flow out only once a specific pressure level is reached, stock is 0.9bar, some aftermarket ones are rated at 1.1bar, etc.. It also allows flow back in when the radiator fluid cools down and acts as a vacuum, thus sucks coolant from the overflow back into the system.

Ideally, if a system is full bleed and working properly there should be minimum fluid movement in and out of the overflow.

Does that makes sense?

Sometimes overheating problems are just because of a faulty radiator cap, so try replacing that first, then bleed the system.

[Paulie C]

So looks like i've got a leaking rad, gonna have a new koyo aluminium to replace the oem one, try and replace the thermostat at the same time to knock 2 birds out with one stone.