4.2 petrol boiling over after 5mins!!!

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.:mad:

Cheers

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

Just been through all of that.

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

Too much.....!!!!

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

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

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???

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?

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..

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!!!

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?

For sure.... as stated Parksy probably did it as cheap as you could but he did all the work himself but it still probably cost him close to $1500 as you need a vrs Gasket set new head bolts as they are stretch to yield and oil and coolant and the head work.

Head gasket. And drop your coolant mix back to 50/50 max. Any more and you loose heat transfer effectiveness.

Including oil and coolant I think I paid about $1200 to do the job with a new head. I ordered the kit off eBay which included new bolts, all seals and gaskets and valves. Runs like a dream now.

Thanks fellas, i'm up for a new head then...
There goes the new rifle:(

sounds like a head, as mentioned check the plugs when mine failed at no6 there was a slight green tinge to that spark plug, you could also do an exhaust gas test on the cooling system. doing it yourself it will probly cost about $800-$1200 by the time you get the head checked/machined, a GENUINE head gasket, new head bolts, exhaust & intake manifold gaskets, from memory it takes around 4 hrs to strip and about 5-6 to re assemble set tappets flush oil etc


edit. if it has gone between no6 and the rear cooling ports check if the bolck is corroded at all, mine was corroded to the point i only had 1mm of gasket material + the soild fire ring which led to a repeat failure, solution was to have the ports in the head welded and epoxy the offending ports in the block, been running like that for about 25k kms now and sits on 82 deg all day even with a turbo bolted to the side of it

found a couple of pics that show the area im talking aboutAttachment 43107Attachment 43108

I wouldnt jump to the conclusion its a head. If you oil is still clean chances are the head isnt cracked. They normal mix oil and coolant if the heads cracked. Most wont even know theres a problem until the gas freezes up due to low water.

We just changed a gasket on my mates for the same issue, filling the overflow with water.

Is your viscous fan working ??

To get your head reconditioned it will roughly cost $1500 - $2000 depending on how much work your head needs, it might go a bit over that if you need a new casting or other hang ons like fan belts, hoses etc and generally includes a service and tune aswell