Radiator Overflow Is Filling But Not Emptying...

[blah_blah]

If the leak turns into a big one it could take your engine with it I guess?

Don't bandaid something like that and just spent the monies now to fix it before it turns into a warped head or worse

I drove my VQ for a year like that, without realising it was the head gasket. It let go in a big way on the dyno during a tune.

Get a carbon test done on the coolant, it should show up any combustion bubbles making their way into the cooling system.

Cot dayum. This is the last thing I need. Fingers crossed she's right for Sandown.

Anything you might want to change whilst your at it with the headgasket off?

yeah I suspected my head gasket, but the combustion gas test came up all clear.... my mates S14 has been running like shit and we couldnt figure it out so I did the test on his and the dye changed colour straight away which means he has headgasket issues.

Its an awesome bit of kit... I got mine from repco for $130, just ring and make sure they have got one first as lots of places were out of stock when I was looking for one.

Here is how it works for anyone who doesnt know....

That's a pretty cool test!

[NIS.26L]

Had this problem on my old engine. Turned out the head gasket had a tiny leak, If I wasn't paranoid about my car I wouldn't have noticed. Not too hard a job to replace.

Does the coolant system stay pressurized after the car is left over night? and does the top hose feel rock hard when warm?

my gtr has this same problem spoken to a few people they all reckon my head gasket must be leaking slightly but the strangest part is the the car doesn't over and heat drives fine!

im pulling the head off over xmas holidays as ive tried everything new caps,bleeding the head like 5 times every possible way,pulled the header tank off,pressure tested the cooling system,and a combustion gas leak detector (TK head check) with no results of whats causing this problem

so if anyone had this problem before any advice would be muchly appreciated

Edited December 2, 2012 by NIS.26L

[HR32GTS 4DOOR]

my gtr has this same problem spoken to a few people they all reckon my head gasket must be leaking slightly but the strangest part is the the car doesn't over and heat drives fine!

im pulling the head off over xmas holidays as ive tried everything new caps,bleeding the head like 5 times every possible way,pulled the header tank off,pressure tested the cooling system,and a combustion gas leak detector (TK head check) with no results of whats causing this problem

so if anyone had this problem before any advice would be muchly appreciated

Yeah with mine It drove fine and didn't overheat. If I wasn't pedantic about it I probably never would have noticed it.

[arrydjay]

Finally figured it out..... had a leaking heater core.. I was loosing most of my coolant through there but also some was going into the overflow and then the leak was preventing it from coming back...

[DVS JEZ]

Excellent. How did u find the leak in the heater core?

[MatthewT85]

so instead of making a new thread thought i might try here for some answers

i never really knew exactly where the temp gauge used to sit but i thought it was just under half, but i had noticed it was getting to just over half, so i checked in the engine bay notice coolant leaking from the top rad hose coming from the plenum, took it off and it was rusted, got that replaced, still is just over half, temp gauge, so looking into it more and noticing after a drive the coolant level in the overflow doesnt move, theres coolant in the rad.

today when i looked, i noticed some white stuff on the radiator around the rad cap, also there was a slight hissing from the rad cap, so cleaned it drove to buy a new one, got home and it wasnt making the noise and no leaks around there, so just wondering if the fact that the coolant level in the overflow not moving is a sign of air in hte system,

i am going to replace the thermostat and change coolant and rad cap just wanted to see if anyone knows what it might be

thanks

Edited January 16, 2013 by MatthewT85

[Missileman]

Replace the cap with a stock oem cap, then look for other problems.

Check the coolant reservoir level when cold, then observe it when hot, it should be higher when hot, then as it cools it should suck the coolant back in to the same level as when cold.

When ever you flush the coolant system, some air will always remain, this will be noticeable when you check the coolant reservoir, because the level of the reservoir will be slightly lower when cold. Then as the air is purged, more coolant will be sucked back in, and it will seem like the the reservoir level will become lower and lower until all the air is purged, only then will the coolant reservoir level become stabilized when cold.

P.S. try not to mix different coolants, flush it and start from scratch if you don't know what's already in it.

P.P.S. When I say flush I mean with demineralised water, not that shitty "radiator flush" that some shyster like autobarn will try and sell you.

Edited January 16, 2013 by Missileman

[MatthewT85]

P.P.S. When I say flush I mean with demineralised water, not that shitty "radiator flush" that some shyster like autobarn will try and sell you.

yeah figured id do that, by this do you mean drain coolant fill with demineralised water, drain again,l then fill with coolant and demineralised water?

[Missileman]

yeah figured id do that, by this do you mean drain coolant fill with demineralised water, drain again,l then fill with coolant and demineralised water?

spot on, until the distilled water comes out clean, then add the fresh coolant

[MatthewT85]

is it enough to drain it through the radiator drain or do you need to undo the bolt on the side of the block?

[The Bogan]

What I do and have never had a issue:

1.Turn on ignition and set the heater to max temp, do not start car

2.Remove radiator cap then remove lower bung from radiator draining all coolant

3.Turn off ignition

4.Replace lower bung on radiator

5.Fill radiator and overflow tank with fresh coolant

6.leaving the radiator cap off start the car ensuring the heater is still set at max temp (this stage removes any air trapped in the system)

7.Run engine topping up as needed until the coolant is hot (I wait for about 5 min)

8.Let the car cool then top up coolant and replace the radiator cap

9.Run up the car and go for a drive to get the car up to working temp

10.Let car cool and recheck coolant level (I push down on the top left of the radiator as it holds some air)

Warning: A hot radiator will be under pressure and you will end up getting burnt if you attempt to open it when its hot.

Sounds like common sense but Ive seen people open up a hot radiator and they usually end up with massive burns.

[Missileman]

is it enough to drain it through the radiator drain or do you need to undo the bolt on the side of the block?

On my 32 gtst I don't bother, the manual says to though, but I find doing it that way a proper pain in the arse.

[Got a Pulsar]

As a side note to this, when I had my Radiator changed, I noticed that my overflow level didn't drop after cooling.

I realised that when Natrad changed the Rad, they had left the hose clamp off the nipple on the Rad where the overflow hose attaches.

Small clamp on there and everything syphons back and forth nicely.

[NIS.26L]

head gasket leak caused all my problems as u can see in the pics but the car never overheated and for some reason the TK head check come back negative too!

[scotty nm35]

It doesn't look split, my VQ was the similar and would only lift under boost and heat. Fixed by replacing with OEM metal head gaskets (using Hylomar gasket spray) and ARP L19 head studs.