Head Gaskets

[Adydas]

Ok guys, Need some advice..

My cars let go of its second head gasket now..

Worked fine last night and has for weeks since i got it back from the last BHG issue, but this morning i took a drive out to head to work and within a few mins under load my car heater went cold ( Odd.. ) and i checked the guage and spotted it overheating..

I stopped got the car home, re drove it tonight after i topped up the water and ended up in the same situation where the water is been forced out the overflow due to pressure from the hg letting go.

Defantly traces this time around of oil in the water, but when the cars not under load it seems to be "fine"..

What needs to be addressed here?

The gasket its self ( both times been metal ), Or perhaps the bolts? or could it be the gallery sizing not cooling enough? If its not those perhaps its the ratio?

Where do i start as its clear the issue is somthing more than what it appears as the car goes hard and mint for a month then lets go (Based on history, dont know if thats a connection per say ).

BHG - All looked like this

[deaf_rattle]

did you check the torque settings this time after 1000kms?

[escortman]

has it let go at same place as last time?

[Dell'Orto]

Can you get a clear pic of where it's blown?

[Boosted_162]

He hasnt pulled the head off yet. If its anything like last time, the headgasket itself doesnt get damaged, it just leaks (suspect the head wasnt torqued up right last time) We are gunna check the headbolts on sunday to see if they have stretched. I think it might be time to get some ARP headbolts!

[deaf_rattle]

dont lift head, try torqing them down again.

[Boosted_162]

dont lift head, try torqing them down again.

Yeah. I dont think Cliff wants to pull the head off now anyway. But somehow i suspect they arent gunna be torqued up correctly.

[rollaholic]

i can only presume the headbolts were replaced with the original rebuild, but either way its probably worth replacing them again at this stage.

personally i think leaving the head on is a crazy idea, but thats me

[deaf_rattle]

personally i think leaving the head on is a crazy idea, but thats me

leaving the head on and checking the torque settings before jumping the gun and replacing the gasket again...

You can replace the bolts with arp stud kit without pulling head off.

That would be what id do. failing that you will need to check the block surface again.

[Adydas]

I checked with the guys and was told they didnt want to nor need to re torque it in the end.. I just dont get why its lasted fine till now THEN gone.. Has it been going progressivly or what?

This is what old HG looked like

The old gasket looked fine but you could see wear marks on the back side where it was leaking, You can see more evidence of this from where the water has been leaking into it and effectivly steam cleaned it all.

Steam Cleaned

You can see it wasnt just one cylinder, but all 4 that had these effects on the back side.
More Washed / Steam Cleaned Cylinders

The block and head was fine last time, and was fine for a time now so the issue is clearly not the surfaces (or wasnt till perhaps now?) id assume that if the head was warped from the word get go it wouldnt seal and would show its issues not work for 5 weeks then naff out.

I think replacing the studds ARP styles is going to be one of my best bets.. If that dont work im not to sure what else it could be? To much boost for the HG? for the Studds? for anything? of is it a heat issue?

[matt dunn]

Was the head skimmed at all,

As they can look flat, and seem flat with a steel ruler etc,
but sometimes unless you take a surface skim off to see you can't tell.

[Adydas]

it was fully preped and skimmed the first time it happened it was checked the second time this time around i would re check and deck it naturally but both if not all surfaces should be perfect..

The head was totally overhauled re valved, built skimmed etc by a pro.. he did my other head and i totaly trust him and his work also taking into consideration where it lets go on the back side ( Inlet ) makes me curious why that side seems off yet the ex side seems fine..

[ChaosAD]

is that a 4age? as they have torque to yeild bolts so you cant retorque them. Or do you just loosen them and redo the process?

[deaf_rattle]

i wouldve still checked the torque settings, better safe than sorry.
7ms in worse case senerios the bolts can stretch/need re torqueing to the point that the bolts are finger tight.

Get a set of arp head studs and replace with head in place.

IF that doesnt fix the problem then remove head and go from there.

[deaf_rattle]

actually, what are they torqueing it down to?
3sge specs or 3sgte specs?

i would want a confirmation on what they tightened them to.
stock torque settings for 7m are 54 ft lbs, (wrong thats why they blow) arp recommends 83 ft lbs from memory.

Turbo cars usually have higher torque settings for the head bolts.

[pc]

Make sure the bolts are well greased too, so that the torque settings are accurate.

[Bazda]

When using those head gaskets I always use copper spray before installing.
Also if you got a headskim and they didnt use a fine enough finish it will leak those those metal head gaskets quite easily.
Ideally you want to use a near mirror finish. This is how we do all our head running metal headgaskets.

[DFECTED]

so are you losing the water out the overflow, into the oil or into the cylinder?

If it is coming out the overflow I would replace the radiator cap, probably the thermostat too.

I'd get the radiator flushed if it hasnt been done also.

The cleanish marks look kind've normal on the piston tops, due to the fuel coming in through the inlet valves and hitting the pistons.

A common problem with 1jz and 7m etc with blowing headgaskets is nobody surfaces the blocks, because they measure flat, but once you take a light cut you can see exactly where the problem is because the is a slight depreciation between a water jacket and a cylinder and you need to take another cut to clean it up.

Metal headgaskets need a perfect finish on both surfaces.

[Malcolm]

Cliff, can you confirm that after the last headgasket went the head bolts were replaced, bolts were greased before torquing, both surfaces were thoroughly cleaned (having both been resurfaced last time?) and the head had been hardness tested? Overlooking any of that could have contributed to the failure.

It would be wise before tearing it down to get the coolant checked for traces of combustion gases, just to make sure you're not barking up the wrong tree.

[Adydas]

Ill comment more tommorow but it passed PK / TK test last time yet still had a naffed HG.. The water was been pushed out of the Overflow under boost only and is doing so again..

The head was hardness tested, acid bathed cleaned and fully rebuilt the first time it was checked less accurately before it was reinstalled this time around and as ive pointed out surely if it was warped or what ever why would it go hardcore fine for 5-6 weeks THEN go?

Radiator, thermostat etc have all been done over totaly from a to b to ensure there spot on, All new parts have been used and was installed with copper spray on a metal HG with new bolts that were lubed up..

Oil was defantly present in the radiator water this time around.. Thermo stat is fine as its brand new from Toyota and the car did the same thing with old one and also with no thermostat.

This is what the head looked like after first BHG