Cyl. head Re-torque problem

[87M-GTE]

Had the HG and bolts replaced with OEM parts about 2years ago. drove it like that since then, and decided to re-torque the head. I followed the factory torque pattern and losened each bolt less than a quarter turn before going at a higher level of lb/ft.
I started by losening a quarter turn then going to 60 lb/ft, I did this through out the first pass. Then I went up to 67 lb/ft, and then on to 74 lb/ft. On #1 head bolt (Intake 1) on the third pass, I turned it gently and never achieved a 'click' from the torque wrench, the bolt also never loosened like a stripped bolt would. I was very confused by this and decided to put it back together and see what happens..I then did a dry compression test on a stone cold motor getting 120-130 psi across the boards..
So after driving for roughly a half hour, no out of the norm temp changes were noticed according to the stock gauge, and upon getting back home I found that the radiator was very low and my coolant over-flow container was full to the brim...?

I have no idea wtf is going on, why the rad is nearly empty and the overflow is full, with consistant compression.

I'm going to fill up the rad and do another comp. test with the motor warmed up to operating temp.

Any ideas or suggestions would be appriecitated..Im considering doing ARPs and calling it a day if the bolt is F'd up, which it probably is.

Thanks
-Sam

 

[rayall01]

After two years, there would be so much crud in the block threads, you wouldn't be able to get an accurate torque anyway. Rebuild the engine, get it machined, and lapped, and install a metal headgasket, with ARP studs. It's really the best way.

 

[CyFi6]

How exactly would the hole fill up with crud if there is a screw in there the whole time and its not open to outside air at all

 

[rayall01]

How exactly would the hole fill up with crud if there is a screw in there the whole time and its not open to outside air at all

What do you think you have to chase the threads for, when you replace the gasket, and what would you call the stuff that comes out of the holes when you do that? You know, that black grungy junk that sticks to the flutes of the tap. In fact, if nothing was in there, why would it be necessary to even clean the threads?

 

[easternguy2005]

Dude this is how my headgasket blows every time. Now I'll never ponder if a backoff and retorque is wise. When my gaskets blow the piston gases rush into the coolant and push it out.

Soda bottle test the overflow.

 

[paradox616]

hydrocarbon test, if fail replace the head with a oem gasket, run a tap through bolt holes and replace with arp bolts @ 80ft/lb....

fyi i would have pulled the bolts out cleaned the thread, lubed them up checked to see if they went in smoothly.

also i BET you didnt do a 2nd or 3rd pass at the final torque setting...
i always do them to say 80ft/lb then do a 2nd pass at 80ft/lb and a third pass, funny thing about fastners, they're designed to strech to give a clamping load, OEM bolts strech once, i reckon your torquing proceedure was flawed or you un did them in the wrong order and warped the head. either way, blown headgasket for you and head off time!

 

[hvyman]

your not going t0 get the head bolt threades filled with crud from re-torqing. when re-torquing you need to break loose about 1/4 turn then re-torque to about 72ft lbs if sock head bolts. fill the rad and drive it if you start getting problems its t the hg. get mhg and your good to go for another 200k.

 

[IJ.]

Who told you to back them ALL off?

 

[T701jz]

lol....

 

[87M-GTE]

when re-torquing you need to break loose about 1/4 turn then re-torque to about 72ft lbs if sock head bolts. fill the rad and drive it if you start getting problems its t the hg. get mhg and your good to go for another 200k.

Who told you to back them ALL off?

I also read it on this forum somewhere in a recent thread found by searching..
Anyways I did 2 compression tests and its all about 130 across the board +/- 2psi.

I havnt noticed any differences in drivability, the only thing is that the rad gets low and fills up the overflow whenever it is driven. there is no change in temp according to the stock gauge.

What is the soda bottle test you speak of?

Thanks for the comments guys

-Sam

 

[CyFi6]

Well if you backed them all off and then tightened them all back down, it probably got coolant and oil and all between the head gasket and the surfaces, and then youre just screwed. Youre supposed to do one at a time in the tightening order

 

[87M-GTE]

I did one at a time in the tightening order..

 

[paradox616]

obviously something got botched up....

soda bottle test i think is sticking a full bottle of water in a 2L bottle of coke and turning it upside down so that the opening is in the radiator cap, start the car and watch for bubbles.

Hydrocarbon test is much more conclusive, tests for combustion gasses in coolant... costs around $20(aud) and any decent radiator shop can do it.

go do that and settle it for good. this test alone will tell you whats required.

 

[Boosted516]

fuck this got me nervous, im debating a retorque just cause this thread. its such a guessing game

 

[T701jz]

I'm curious if the TRSM calls for re-torque the bolts after "2yrs" or at any period of time. I've been around Boilers, Compressors and Pumps to know you're just asking for trouble to re-torque those blots and re-compress an old gasket seal. It takes only a hair-line crack on that seal to leak (gas). Those bolts were prep probably with loctite (crud).

 

[Another MkIII]

Yeah, from what I've read, re-torques usually cause BHG's rather than prevent them. You're better off to just let nature take its course and then when the HG finally does fail go with ARP head studs and a MHG, and make sure you get the block and head machined.
-AM3

 

[jdub]

A re-torque in an attempt to stop the beginning of a BHG or after an excessive amount of time is not going to work.

A re-torque after 5 or so complete heat cycles after completing a HG job is a good idea, especially if bolt or stud preload was not set properly during the install torque sequence.

 

[Boosted516]

is there anyway i can tell what my heads been torqued to then? because i dont know what the previous person who did the rebuild set it to and i dont want turn the boost up without knowing.

 

[crisp]

is there anyway i can tell what my heads been torqued to then? because i dont know what the previous person who did the rebuild set it to and i dont want turn the boost up without knowing.

At this point, I would feel comfortable in suggesting the mhg and arp's and you may as well make it a "freshen up". (Varying degrees available... by budget and skill.)



The head on a sevenem is not something to be gambled with. imho.


...better to KNOW.


EDIT: ^^^ er... some of you will laugh at that! ...being a "clown-car-drivin'-gambler" myself. DOH!


g/l

-crisp

 

[max-89supra(t)]

you get good compression all across is because the head is cold when you do that test......and guess what happens when you start driving around??? things heat up a little=expansion! a tiny flaw like a stripped or stretched head bolt( or in my case a non machined head and block+mhg) will push the coolant out with the high cylinder pressures when the head heats and warps/moves!