Member - Cookster(VIC) replied:

Don,

For how long did the pressure test go? I had a problem with my previous Patrol 2.8 diesel, loss of water with no obvious leak. With the pressure tester we put on a lot of pressure and left it sitting for a few hours. Somewhat 4 litres of water vanished and there was no puddle under the car. We gambled and started the engine – what a nice fountain that was. It was the head, it had a hairline fracture close to the exhaust manifold. All the water was running into the exhaust but luckily no damage to the motor. A couple of weeks later and after a few thousand dollars went up in smoke (new head) the beast was back on the road. I hope your problem will have an easier solution.

Cheers

Member - Captain (WA) replied:

Hi Don,

I had a similair problem with my 1HZ 80 series. It turned out to be a hole on the radiator core. It was behind the shroud and you could not see it. I kept loosing coolant over time with no obvious leak until on a trip up North it finally let go in a big way. A can of Bars leak was a temporary fix (for a month!) until I pulled the radiator out and had it repaired properly (simply sealed off one core and pressure tested ~$50).

Cheers

Captain

Member - DOZER replied:

Hi
Have a good look around for white residue from coolant. Places to look are around the rad, thermistat, water pump etc. Sometimes the pump seal leaks when cold, but not when hot. If u can feel or see residue from spray from the fan when cold, it is the pump, and what a joy they are to replace.....did the last one in the Tibaburra Caravan park....the cam cog, belt, and backing plate all has to come out....and go back in the right way!
A hydrocarbon test is probably your next port of call if u cant find the culpret.
Did the motor overheat badly with the thermistat problem??
Problem is (and ive seen it many times) that once u overheat things, everything starts to fail...water pump, rad, etc etc. The top and bottom tanks are sealed by orings, the water pump by carbon seal.
Andrew

Member - DOZER replied:

Thats good, check under the oil cap for gunge aswell...if there is water going in to the oil, it will show up there. Problem is if it got too hot, the combustion chamber may have cracked, and water might be displaced by compressed air, so getting a mechanic to screw a nice nifty cap on and start the motor is the next step.
Andrew

Davoe replied:

1-2 litres? coolant has a distinctive smell and if you cant smell that much or see it leaking you have a cracked head (speaking from all to recent experience) and you dont need water in your coolant or vice versa to make it so hope I am wrong