triton V6 - blown head?

i wonder if this is like the holden pre ecotec motor that some times get a airblockage ?
if it is well heres what i did
loosen the very top hose (when not hot) and let the radiator run through (motor on) ensuring adeqeute cooling this shoul let all air out and replace and tighten hose and check for leaks?
maybe maybe not

You definetly have a pressure leak between the block and the head.

Probable causes are: 1.Head gasket blown/burned/screwed
2. Improper tightening of the head bolts
3. Warped head (could be the result of n.2)

This is definetly a serious fault and I would fix it as soon as possible. Engine damage can and will occur if the leak gets bad enough.

Just changing the headgasket might do the trick. Just hope the head isn't warped............or that is has a hairline crack.

Also, if you run the engine hard and then shut if off without letting it cool via idling the result could be a cracked head.

had the same problem with a surf, was a leaking head gasket. The head was not cracked and was able to be used again once inspected with no major repairs to it. A pressure test and chemical test on water proved nothing, in the end had to bite the bullet and removed the head to see the problem. Head was fretting between 2 and 3 pots and showed clear signs of this on the alloy head.
Air locks are also a big thing, manufactures like to have the rad lower than the engine block (design etc) and this bugs me. I have made a adaptor out of a 2ltr bottle ,machined up a thread to suite and an oring to fit into where the rad cap goes to help raise the high point and bleed of the air...works well

Is there milky substance up under the oil filler cap? ie. water in the oil. Pretty good chance you've got a blown head.

TonyH,
before you start thinking of the expensive options.
Is the thermostat opening ?
let the motor get to operating temperature and check to see if both hoses are hot. (watch those fingers) if both hoses are hot it would indicate that the water (coolant) is circulating.
has the triton a electric radiator fan, is it coming on. the fan should come on when the coolant reaches a certain temp. and when the temp drops down will cut out.
also make sure you are filling the overflow bottle to the correct level, if you over fill the bottle the pressure bleed off from the rad. cap will cause you to lose any excess coolant through the over flow.
regards Will

have a TK test on radiator done it will tell you if exhaust gasses are getting into cooling systerm also radiator could be blocked the TK test can be done at a radiator shop or by a mec work shop
good luck

Guys
as I said in my opening question this is not performing like a normal blown head gasket ie. no bubbles in radiator, no water in oil. Will pressure test the cooling system tomorrow but if it is a head gasket i will be surprised but not in a big way. As a cockie I see the same thing break 10 times and each time show a different symtom.

Tony H