3S-GTE Losing water/Overheating. Suggestions to diagnose cause?

[OnAll-FOUR]

Grrr my car lost water and got hot again on the trip back to Sydney from Canberra so i would appreciate some suggestions on tests I can to to diagnose the issue. I would like to avoid stoping on the federal highway at 21:30 on a sunday night again

I have been driving it arround the sydney streets for the last 3 months scince last time it happened when I thought it was the radiator cap and have hand no dramas. I topped it up with water on Friday before heading down to canberra and it needed 600-1000mls of water in the radiator. Drove down to Canberra fine and drove around Canberra over the weekend fine as well.

But on the way home, the same as last time, going through the hills just after Golburn I noticed the temp guage starting to fluctuate. Eventually it was fluctuating to much and as soon as it got up to 3/4 on the guage I stopped and got a top up of water from NRMA. After that fine all the way home.

So I would appreciate any suggestions on test I can do to diagnose the water loss issue.

- TK test again from NRMA man was okay suggesting no blown head gasket. Could their test kits be faulty? We were also trying to look at it in the dark last night.

- Pressure test was okay after the first time this happened. Car seemed to hold pressure okay last night after the top up of water, the top hose was under pressure. I will get that tested again.

-Water pump is working, I could see it pumping coolant round after topping up the water.

- Cap is new, replcaed after this happened the first time. Running a 1.1bar cap

The car has always seemed to love dumpping water after stoping from a drive where the car is up to temp. When the car is stopped the water in the system seems to boil and you can hear it all bubbling though the system to the overflow. I know this is relatively normal, but is thre way to guage if this is any worse than normal? Is this symptom of something else? It seems to boil so hard that it empties the overflow bottle buy bubbling the air/steam through it.

I suspect what ever is causing the water loss it made worse by long runs at boost prssures up the hills like the ones out of Golburn. And possibly why I don't notice this too much putting round the traffic in Sydney. Could it be a head gasket/head stud issue under boost and maybe why it isn't picked up with the pressure test? But that dowsn't explain why the TK tests didn't pick it up.

My other thought is it could be this issue with loosing water after stopping, and not refiling properly from the overflow?

[Fish]

could be a crack in the head.

Now when it dumps water how much is it loosing?

have you let the thermostat opening fully and know that the engine has the right amount of water coolant?

does the heater leak?

i'd be ripping the head off and checking for cracks warpage.

or take it to your mechanic

[GBC_069]

Ben,

My GT4 used to use up a little water over the years also. As in 500ml every mth.

It would never overheat like yours is however, can you pull up water temp on your ecu? Mine sat around the 87-90deg mark....

My compression was also variable, some months were higher than others, no idea what was going on there.

could be an intermittent thing, mine was and still is slightly intermittent, but was like it for atleast 3 years.....

goodluck buddy, hope she's ok.

[midnight_purple_GA70]

I would probably 2nd the crack in the head or slight BHG between a cylinder and a water gallery... just enough for the gas to heat the water up and cause heating issues and thus pump water out the overflow bottle/make it boil and bubble away as you describe...

I had a very slight BHG in the 1g-gte the car would run fine and after an hour of driving would start to overheat... so not exactly the same as your symptoms, however when i had the tests done for BHG it was deemed to be fine...

[MWP]

Had the same issue with my old Starlet GT.
Was fine around the city, but on a long trip it lost coolant and overheated quite badly.

It was a very minor blown head gasket.

[OnAll-FOUR]

Thank you guys sounds like It might be time to open my engine up and replace the HG and I can check the condition of the engine as well.

For the guys that had the minor blown HG, were you able to test for it at all ? how did you know that was the issue?

Were you able to visually see signs of the blown head gasket when you opened it up?

[OnAll-FOUR]

could be a crack in the head.

Now when it dumps water how much is it loosing?

have you let the thermostat opening fully and know that the engine has the right amount of water coolant?

does the heater leak?

i'd be ripping the head off and checking for cracks warpage.

or take it to your mechanic

I will check the levels out tonight (haven't touched it after getting hoome). It had a full overflow bottle and was dumpping fluid when I stopped so in theory I should be able to check the overflow bottle and water level in the radiator an check the return valve operation.

The heater deosn't leak as far as I know. I will try check this as well. I assume i'm looking for signs of crusty coolant dried up under the dash?

[midnight_purple_GA70]

when i had the slight blown head gasket i didnt discover it... i traded the motor along with another 1g-gte for a 1jz and then found out later that my motor had a BHG... i believe it was a visual once the head was lifted but cannot confirm that...

[TRDcelica90]

i had this prob also mate.. tried everything before we realised it was a slight BHG.. the water jackets had corroded and water was escaping there also..

Did you check your little hoses that goto the water oil cooler?? there in a bad position and can go bad and be hard to stop. you could be loosing fluid there and get air stuck in the system and make it overheat.. just another thing to add to the list lol

[TH Performance]

Hi guys


In my experience (I had 4 GT4's during years), our car has a shitty cooling system.

Boiling of the water is BAD BAD thing, not normal, as a thread starter said.

This boiling erodes the block and that is why our block crack at higher power. Because they are already damaged for years with steam pockets in the block/head.

There is only one way to sove the problem. And that is to ditch the stock idiotic cooling system, to make a closed loop cooling system like modern cars have.

That is not hard to do.

You have to ditch the overflow bottle, make a swirl pot with air escape vent on the top, and make a header tank with pressure cap.

If you need more explenation, be free to write here. Once you make it that way, all the troubles with the cooling are gone and your car WON'T boil anymore, nor it will have any more air in the system. Which will give you better cooling!

[OnAll-FOUR]

Your talking about boiling while running or boiling after stopping?

Also when you say closed loop cooling system can you expand on that? how do these deal with the excess water as they get hotter?

I went down and checked the car, basically no water is left in the overflow and required 500mls to top up the radiator to the top. So all that water is lost just from the drive from Mittagong to home. (~100kms) and refilling the system after cooling.

So symptoms seem to suggest slight BHG, are there any other things I can check before I open it up?

TRDCelica90 I know the hose your refering to, and it is also a suspect. I replcaced that hose about a year ago but there is possibly some leakage arround the new hose. I will try get in and replace that as well.

[TH Performance]

this is connected. both boilings. you loose water while driving through the radiator cap! and the you boil because of lack of water.
you also loose water after stopping because of the air and excess pressure in the system.

that is what I know, not what I guess.

[midnight_purple_GA70]

this is connected. both boilings. you loose water while driving through the radiator cap! and the you boil because of lack of water.
you also loose water after stopping because of the air and excess pressure in the system.

that is what I know, not what I guess.

i can see your point with this idea...
however i dont understand why it is such a problem with the GT4 and isnt an issue in supras which run a very similar setup...

what colour coolant are you guys running?
I know in a JZ green coolant will corrode the alloy heads quicker than red coolant...

[neal]

How good is your radiator? When was the last time you changed your thermostat? What i'm getting at is just check all the basic and simple stuff before you go ripping your head off.
It seems your car starts to heat when under load, may be your radiator is not up to scratch.

[OnAll-FOUR]

hehe it is easy to get carried away and tear it all apart

I will start saving for opening it up, but in the mean time I will try the smaller things. To start with I'm going to replace one hose that might be suspect, and buy yet another radiator cap. Speaking to some engine people, they are saying the CPC radiator caps appear to be having issues at the moment.

Termostat and radator flush will be next on the list.