Exhaust manifold stud / nut loose, broke gasket??

[FCD]

About a week ago my 1988 Ford Escort developed an engine tick, first only on acceleration, then also at idle.
It got me worried, i thought one of the hydraulic lifters had given up the ghost, but upon close listening the noise was not coming from the valvetrain
I have been driving it for the past week as is with the mystery engine tick.
Yesterday i was checking the oil and coolant, and i noticed this :

CVH Exhaust leak by Argentum Enim in Sempiternum, en Flickr

The soot of the exhaust gasses is very evident, then i also noticed the nut you see in the picture was so loose you could turn it by hand!!

I took out the stud and nut, sprayed it, and all the nuts with WD40, some were a little bit loose but they only allowed for maybe 1/4 turn more, put in the stud again and re-tightened, after this is still makes the noise and in fact it has an evident crack in the gasket.

I'm thinking it might have to do with the fact that it overheated a couple weeks ago due to a faulty engine fan temp sensor switch, what do you think?

I plan on changing the gasket as soon as i have time, Ford recomends torquing the studs / bolts to 11.8 lb/ft when putting the manifold back on, i do not have a torque wrench, is it absolutely necessary?

 

[BrocLuno]

Gotta check exhaust manifold bolts/nuts annually. Heat cycles will loosen them easily. You can use Class 3 interference nuts (no nyloks) and they will stay tight. But put them in with never-seize. If they rust in place, you will bust the stud trying to remove them ...

 

[FCD]

I'll be as careful as possible when taking them out, will spray plenty of WD40 on them and let it soak before attempting to take them off.

 

[Shannow]

Gasket is gone, but you knew that.

http://boltoff.com.au/

Has been good to me for getting stuff off.

 

[Shannow]

Have had people in the past swear by getting the bolts hot (not red hot), and letting white candle wax suck up into the threads

 

[andyd]

Split the nuts with a cold chisel or a Dremel. Use a hand impact driver to loosen up. Hand tools and patience. Another trick is to drill a hole in the face of the nut.

 

[FlyNavyP3]

I'd strongly recommend using an actual penetrating lubricant. WD-40 is great for a lot of things but there's a ton of products better suited for removing fasteners.

 

[FCD]

Hmmm, ok.