GTT Overheating - Recovery Steps

[MikeR34GTT]

Hello fellow SAU'ers,

After a bit of advice on my R34 GTT that had just overheated last Thursday suddenly, to the point of the H-line on the water temp (I panicked so bad) and what my first course of safe action should be?

Problem: overheating according to high water temp and oil temp at half way on stock gauges

Observation: overflow tank full (but dirty), no coolant in radiator which I checked tonight as I've not been driving it since, water pump and thermo replaced at 110k, I am the second owner now at 170k - I have the original service papers to back this up. No visible leaks, although after hours of driving on Thursday, noticed leaks when coming home, I was stuck for time but at a quick glance have not noticed any cracked or burst hoses and thought this may have just been the overflow kicking in.

Action: I have a new Nissan thermostat to go in, was initially going to remove my rad, take it to Natrad for flushing/cleaning, bleeding the system (myself) with distilled water and whatnot at the same time and replacing the thermostat (myself) also.

Would this be a safe route to take before just handing over the whole car to NatRad and them slugging me $600 when I could have just fixed, eliminated or even alleviated some of my problems?

Cheers

[V28VX37]

I boiled mine couple of weeks ago at the track, turned out to be a leaking water temp gauge sensor mount that spat out just enough coolant for the system to start running dry.

Here were some of the theories thrown around originally: http://www.sau.com.au/forums/topic/463353-post-track-day-qs-rotor-wear-gearbox-oil-ps-pump-manifold-nuts/?do=findComment&comment=7762451

If you're not in a rush you could try bleeding the system thoroughly yourself and carefully checking for leaks before taking it in?

[admS15]

Overflow bottle full and no visible water in radiator. Try a new radiator cap as a quick fix and hope remedy. It sounds like the cap is letting the coolant go to the o/f and then engine is getting too hot. good luck and hope it's a simple fix.

[MikeR34GTT]

On 15 August 2016 at 10:55 PM, admS15 said:

Overflow bottle full and no visible water in radiator. Try a new radiator cap as a quick fix and hope remedy. It sounds like the cap is letting the coolant go to the o/f and then engine is getting too hot. good luck and hope it's a simple fix.

Will try this and report back - mates are saying it could even be a head gasket? Seriously?

Defintely still running fine, no white smoke etc. possibility?

[admS15]

Will try this and report back - mates are saying it could even be a head gasket? Seriously?

Defintely still running fine, no white smoke etc. possibility?

It can be a Hg but you would want to investigate all other possibilities first as Hg is a pita to replace. Try the cap and let us know. Fingers crossed for you mate.

[pvdm]

My NEO motor in a manual stagea was overheating also. It turned out to be a small leak in the plastic end tanks of the stock rad. Was only enough to lower the system pressure and then the coolant would boil at the turbo and the car would then overheat. Check that your hoses are hard with pressure when it overheats. If they are not, then you have a small leak somewhere. I replaced the rad cap and thermostat before i found the leak and it did nothing. A full aluminum rad from just jap or ebay is an easy job you can do at home if that is your problem. By the way, when looking for coolant leaks, you may not see any fluid, only the white residue of the boiled dry coolant. Look for that instead of liquid coolant. Hope its not your head gasket, you can test for CO2 in your coolant with a tester from repco. Or if its bad enough, you will have bubbles coming to the surface with rad cap off and car idleing. You may also have oil in your coolant or froth in your oil. Look for that. Good luck.

[MikeR34GTT]

Rad is absolutely cactus.

Not having much luck finding an aftermarket replacement for auto, that fits the stock shroud, and has the two oil cooler nubs for the auto box.

[MrStabby]

Cactus as in blocked? You could try having it cleaned (repaired?) by a pro. They should be able to tell you how well it comes up after.

[KiwiRS4T]

Buy a stock replacement - at least it will fit and possibly last another 25 years.

[MikeR34GTT]

5 hours ago, MrStabby said:

Cactus as in blocked? You could try having it cleaned (repaired?) by a pro. They should be able to tell you how well it comes up after.

As in full of little dents and creases, full of dirt and bugs and there's a huge black area like it's burnt out.

Ive got a JJR OEM style replacement on the way I'll fit tomorrow and report back.

[MikeR34GTT]

About to refill the rad and bleed the system.. what's the proper way? Use the two bleed screws as I add coolant or the old Coke bottle in half trick?

[niZmO_Man]

I've used Coke bottle technique with good results.

[MikeR34GTT]

Alright gents, new JJR OEM rad, replaced thermostat & rap cap, full coolant flush, replace and system bleed has rectified my overheating problems (so far, need some warmer weather to really trial this).

 

hopefully this will help anyone else with this problem and not to immediately jump to a head gasket conclusion