4.2 petrol boiling over after 5mins!!!

[tiny]

Hi guy's i have a new problem and i think it may be major....

When i first purchased the gq it ran hot and after extensive problem solving and replacement parts it started to work fine..

Things Done..
Full system flushed
New thermostat
new waterpump (not needed, bugger)
all new hoses
new temp sensor
1.1 radiator cap instead of stock .9
car put on 45* angle and all air bubbles/locks out
new fan, hub is working fine..

no water out of exhaust?? no water in oil?

I'm stumped, coolant is 70% concentrate so boiling point must be well into 100-120 degree? and everything is flowing??

This just started happening yesterday.. turned around and took the bike to work. Its not even a hot day and its doing it still after i gave it a fresh flush and filled up with almost all coolant..

Please be a basic issue i've overlooked but my gut says fooked head.

Cheers

[Bloodyaussie]

Head gasket mate!!!!!!!!!

Just been through all of that.

[tiny]

Faaaark, great!! What it cost you.. if you dont mind me asking??

[Bloodyaussie]

Too much.....!!!!

I know Parksy did his himself for a lot less....

[threedogs]

What condition is your radiator in,you could remove and get it rodded
As that's the only thing left,

[Bloodyaussie]

Before thinking the worst you can run some tests to confirm this.... need to google the procedure but most times it will be the rear cylinder that will go and if you can get to the last spark plug and have a look at it to see if it has signs of water on it.

Is there any signs at all that the radiator is leaking??

Is the overflow filling up?? and is it sucking back into the system after it cools down or just staying full???

[Parksy]

Yes same thing happened to me the other week also. Unfortunately the thing that fixed it was a new head. The gasket looked perfectly intact, so somewhere my head has a crack or 2.

But I had milky oil.

I'd start with using the top off a coke bottle as a funnel on your radiator held on with electrical tape. This way you can see what's happening without coolant pouring out everywhere. Maybe pinch the over flow line so the coolant doesn't fill the overflow tank. If you've got consistent bubbling, then it may be bad news.

What condition is your radiator in? When you say overheating, is that indicated on the dash gauge?

[tiny]

No leaks anywhere, radiator was pressure flushed and deemed fine.. This happened with a click of the fingers so something has let go or failed...

I have a gut feeling the bloke i bought it from has done a stop leak job as it didnt have thermostat so no real pressure and now its blown through?? or its just blown of natural causes.. Motor runs smooth so i think ill check plugs on the weekend.. motor is worth keeping? 208k's

Not sure if i can do myself as i live in units and the body corporate frowns on any mess, ive had mobile auto elecs down there but it looks bigger than a one day job.. Will have to go to mechanic, anyone on the sunshinecoast anygood?? Rough idea on cost and is it worth it..

[Bloodyaussie]

About a weeks worth of work mate with pulling down and then sending the head off to get worked or you can do what Parksy did and buy a head... if a shop does it be ready for close to $3000 easy!!!

[tiny]

Yeah i'm kind of guessing that.. I had that sinking feeling when the guage went skyward and started to blow steam out of overflow.. So your saying cant just change gasket? should reco head at same time?