Headgasket Failure

[mitsiboyblue]

Was hoping not to do the rear bank as it tests fine compression wise. This engine is fitted in an FTO and would mean engine removal to get the rear turbo out

Pretty sure the piston isn't melted, just a black mark in the middle, will check properly tomorrow though

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ok my friend, im guessing with that additional amount of work involved i understand your predicament.
fingers crossed

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[dazjb]

Cheers

Been on Viamoto to order the parts needed. When it comes to head bolts there are two options.. Genuine Mitsubishi or Aftermarket Copy. Obviously the genuine bolts are more expensive

Is it a good idea to stick with the genuine ones?

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[Nick Mann]

I've gone for ARP. I'm pretty sure I was getting head lift with raised boost, I was losing a little bit of coolant and was getting bubbling noises occaisonally after a spirited drive. I changed the head bolts to ARP and the problem has disappeared. I didn't take the heads off, just changed one bolt at a time.

[dazjb]

If I had the funds ARPs would be great but not the path I can go down at the mo. Going to play it safe with the genuine mitsi bolts and stick with 1 bar boost.

Checked the other piston, nothing in the way of melting.. just a bit of carbon build in the middle. It can be picked off with your fingernail

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[dazjb]

Been in touch with my engineering bud. He says as there is no evidence of the headgasket letting in water and the head doesn't look warped (checked it with a straight metal edge) then I should get it pressure tested in case it has cracked! I hope not

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[Nick Mann]

I wonder if you were getting head lift too?

[mitsiboyblue]

If I had the funds ARPs would be great but not the path I can go down at the mo. Going to play it safe with the genuine mitsi bolts and stick with 1 bar boost.

Checked the other piston, nothing in the way of melting.. just a bit of carbon build in the middle. It can be picked off with your fingernail

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It sounds possible there could have been 'head lift' but im guessing there would have been some supporting visual evidence on the head gasket to back it up?
If the head is perfectly flat usually thats a good indicator there hasn't been any excessive heat to cause distortion.
So yes you need to get it pressure tested, also.... but its highly unlikely you should check the upper 2/3rds of the cylinder wall for the tiniest of cracking aswell.
I'm not trying to scare munger but....
Im looking at that last picture you've posted and i can see or what looks like slight bluing on the very top of the cylinder wall. If that particular cylinder has been leaning out through a clogged micro filter in the injector body its possible there's been high temperature combustion and there is a possible crack somewhere.
Water has to have been getting in somewhere looking at those pictures.
Does anyone else see it?
Dave O

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[mitsiboyblue]

I wonder if you were getting head lift too?

Sorry.... thats not the cylinder in question is it!

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[mitsiboyblue]

Sorry.... thats not the cylinder in question is it!

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Sorry i know that's not the cylinder in question but the theory is there....

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[dazjb]

Checked the other cylinder and there isn't any signs of blue on the wall, must have been something to do with the lighting.

Dropping the head of tomorrow to get pressure tested and they can check the surface properly to make sure it hasn't warped.

Need to remove the cams first though, it's there a specific way to remove them or is it just a case of removing the guides and lifting them out? Checked the manual and it doesn't mention anything specific.

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[mitsiboyblue]

Checked the other cylinder and there isn't any signs of blue on the wall, must have been something to do with the lighting.

Dropping the head of tomorrow to get pressure tested and they can check the surface properly to make sure it hasn't warped.

Need to remove the cams first though, it's there a specific way to remove them or is it just a case of removing the guides and lifting them out? Checked the manual and it doesn't mention anything specific.

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Just make sure loosening of the caps is done equally until there is no valve spring resistance acting on the cam lobes and keep them in order (ex & in seperate) and the casting marks of the caps for the forward position are noted.
Thats it.

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[dazjb]

Got ya...Thanks for that

Also just checked the cylinder wall with a torch, no cracks that I can see.

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[mitsiboyblue]

Got ya...Thanks for that

Also just checked the cylinder wall with a torch, no cracks that I can see.

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Im glad you cant see any cracks in cylinder wall.
Im just thinking and i bet you haven't checked this....
look closely at the head gasket again but on the compression ring itself, of area that is exposed to the compression chamber. this is the folded part of the compression ring that is physically in cylinder. look for cracks.
If there is a crack here the gasses can pass through the stainless steel layers into the cooling system and vise a versa.


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[dazjb]

Just checked the gasket and you can seperate all the layers around most of it. It looks like it's made this way, none of the parts seem sealed at the edges b2308b0bfe9bf64d29005f6ad88dc45f.jpg

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[mitsiboyblue]

Just checked the gasket and you can seperate all the layers around most of it. It looks like it's made this way, none of the parts seem sealed at the edges b2308b0bfe9bf64d29005f6ad88dc45f.jpg

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Thats a different kind of gasket to what i was expecting to see, but the theory of leaking between the layers is still the same. If you have been getting 'Head Lift' on boost gasses and coolant can and will leak between the layers.
if the head comes back with no cracks i think it would be safe to say that was the cause.
Also just double check your cylinder block face is perfectly flat also.
Dave O

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[mitsiboyblue]

Thats a different kind of gasket to what i was expecting to see, but the theory of leaking between the layers is still the same. If you have been getting 'Head Lift' on boost gasses and coolant can and will leak between the layers.
if the head comes back with no cracks i think it would be safe to say that was the cause.
Also just double check your cylinder block face is perfectly flat also.
Dave O

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Thanks for the picture its tells a 1000 words

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[dazjb]

I don't think head lift is the cause of this. Never had a problem until I used the coolant flush and now it sprays water out of cylinder 4 even when the engine is cranking over.. no boost present

Dropping the head off tomorrow to be pressure tested and checked properly for warping. Fingers crossed

[dazjb]

Head pressure tested and is fine. Very slight warping around cylinder 4. The guy only needed to take 3 thou off so hopefully compression won't be affected too much

I mentioned how nothing stood out re the gasket being damaged and he said with these metal gaskets it's not always obvious, unlike the older composite ones where you could clearly see the failure

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[Nick Mann]

Hopefully all sorted!

[dazjb]

Finally got around to replacing the headgasket after I took the car off road for the winter.

I'm concerned about how tight the head bolts have to be. They need tightening 30nm + 120° + 120°. I've done the 30nm then using an angle gauge tightened up to the first 120° but I have to use a breaker bar to achieve this and its very tight... and I have yet to tighten another 120°! Bit worried im doing something wrong here and if I tighten up another 120° that I'm going to strip something and be up the creek.

Is this normal for head bolts? They didn't seem that tight when I undid them to take the head off.