possible head gasket dying???

[4efteboost]

i done my head gasket bout 3 months ago with all new head studs etc and followed all torque settings..
i keep getting coolant filling up in overflow tank after hard boost and its only after about 5400 rpm.
it doesnt completly piss out but does fill up by an inch or so but then goes back down by itself after, ive now changed the thermostat, raidator & rad cap and still got the same problem.
car is running 183bhp on a hybrid ct9 and 0.9bar boost with all supporting mods. i have also done a compression test and all cylinders were pretty much the same reading.

any help would be much appreciated

 

[sx_turbo]

it will be worthwhile doing a combustion leak test, you can buy the kits from ebay, it a blue dye, that you poor into a tube and put the tube in the neck of the tank, if it changes colour to yellow/green then it is gasket failure.

now these engines unfortunately are prone to block warp and the slightest sign of warpage will cause this to happen, even if the warpage is within tolerance, if dave burwash was still around and toby they would back me up.

there could be other reasons for the gasket failing aswell like the head being warped or just a bit of dirt on the head or the block still, its also recomended that the bolts are replaced aswell.

 

[4efteboost]

im gonna try find someone with a leak down test as i dont fancy buying one, when i done my head gasket i had the head sent to the machine shop to check for flatness ect and was fine and was also cleaned. the block was flat when i checked it aswell and i did replace the bolts when i put it all back together. pretty much replaced eveything lol

 

[sx_turbo]

yeah try find someone with a leak dye test,

thats pretty much all you can do really mate,

the other thing is the head may have been skimmed incorrectly, i have had in the past where the skim that was done was to corse, and meant the gasket didnt seal correctly, they neet a very fine skim being aluminium.

not really sure what else to recomend to be honest mate

 

[4efteboost]

yeah im sure someone has one or i will just pop to a garage and get them to do it. the head wasnt actually skimmed as it was already flat due to doing a headgasket about 7 months before when the engine was rebuilt. problem after problem with the thing

as it is dead at work today i just refilled coolant system and there was a constant flow of bubbles for about 10-15mins and i put cap back on then took her for a boost and again the coolant went straight into overflow

 

[Texx]

the block was flat when i checked it

How did you check it? What was the maximum run out that you measured?

Are you using a steel gasket or an OEM gasket?

 

[4efteboost]

not sure on the measurement as my mate was the one who checked it with some sort or tool. as for the gasket itself i used the stock OEM one with stock head bolts

 

[STARLET N/A]

did you torque them yourself? i believe its 30, 60 and then 90 degrees

 

[dac69er]

I have a similar problem. Its only under hard boosting for long periods, otherwise you don't notice it. I'm half tempted to give the headbolts a tweak and see if that helps, saves ripping it all apart. I have replaced the rad cap and it hasn't overflowed yet, everytime I check the coolant level its fine!

 

[Dan3SGTE]

Is the car overheating along with this?

If not could it not be an air lock in your system? Or rad cap not maintaining pressure to keep a lower boiling point?

 

[4efteboost]

Nope car is not overheating or giving off any other signs of head lifting or gasket failure, i spoke to a geezer who used to race kp60's with 4efte engines and he said the first thing he used to do was either take the thermostat out or drill holes for better flow as because of the higher power an boost the pressure gets too much and the thermostat is blocking the flow too much so im gonna give that a go and see if it works

 

[Texx]

i just refilled coolant system and there was a constant flow of bubbles for about 10-15mins and i put cap back on then took her for a boost and again the coolant went straight into overflow

For air bubbles to be rising at the top of the rad there must be air in the cooling system. The air could be an air lock escaping (though it's unlikely you'd get an air lock in the 4E cooling system and if you did it would most likely escape to the top of the rad after a couple of heat cycles) or air is being forced into the cooling system via a leaking head gasket. Seeing as the air is pressurising the cooling system enough to crack the cap open in such a short length of time, the air is most likely the result of the head gasket failing to seal sufficiently.

Having said that the stock rad is toss in terms of cooling efficiency, after giving the car a good hard blast it would not be unusual to find a significant amount of coolant in the expansion tank.

Try your stat mod, if that doesn't work you may find yourself pulling the head back off.

 

[4efteboost]

i have one of the civic alloy rads off ebay and ive been told that its quite normall for coolant to go to expansion tanks with one, went to a big cruise in hertfordshire lastnight and was boosting and did get coolant in expansion tank but when it cooled down it seemed to go back down and rad had normall amount of water in it, someone told me to expect this with this size rad?

 

[wildchild]

its normal for water to fill and decrease in coolant tanks. when engine is heated up the water expands and the excess water is forced to the coolant reservoir. when the engine cools down, the water is sucked back in from the coolant reservoir to the radiator. Thats normal operation. if your radiator cap seal is damaged then water doesnt get sucked back in. this goes on until coolant reservoir gets filled and overflows resulting in less water in the radiator which causes your engine to overheat which i dont think is the case in your car as you say it doesnt overheat.