Missing gasket

[Andy Bennett]

I ventured out on our New Year's Day run with  a slightly pleased look on my face, having fitted my new Electronic Ingition Distributor and being happy with its tweaked timing.
Life was all good until about 20 miles in and a spluttering and loss of power. With the head gasket suspect we took a ride home at the excellent hands of RH and SOS services. Not so pleased with myself anymore.

Today and a compression test showed zilch compression on 2 and 3 so it was off with the head. 
The head gasket was last replaced about 4 years ago. I tightened then to 20lb, (repeating after a run), but it did feel like some were looser than others when undoing them today, so perhaps they had loosened off?

This time I decided to be a little more delicate about removal so made myself some extractors using hollowed out spark plugs and plates across the studs. 
 
This left the gasket in place and revealed below, a missing chunk between 2 and 3. I cannot see it anywhere (it isn't on the head). I haven't yet poked in every corner in the valve area but it is not obviously there. Surely it couldn't have vapourised or been sucked away into the water cooling system.


  gasket.jpg (Size: 297.14 KB / Downloads: 686)

Anyway, that curiosity aside my real question is as follows.
Prior to this failure I had noticed some bubbling around head stud 3 (centre back). Nothing too bad but just blowing a few water bubbles from around the stud.
With the head off it seems right to also do something about this. Stud 3 doesn't have any water way around it and is well away from the failure so I guess the water is coming up around the stud thread. The solution would seem easy, remove it and replace (I have spares) with threadlocker to seal. 
However, under gentle persuasion it does not want to move. I have locked a couple of nuts on it and turned but it is solid.
Given the problem I am trying to solve, do I:

Persevere with the spanner and risk snapping the head stud, opening up a whole new world of problems?
Heat it up, but I only have a pretty large brazing torch so it won't be delicate, although I could make up some baffle to protect the surrounding areas?
Try to clean up the top of the stud thread into the block and then dribble down thread locker, appreciating that I am only going to get down a half thread or so, and then back it up with lots of goo around the stud base to seal it off?

For goo, I know that is a whole thread of its own, but I have red Hermatite, blue hylomar and some Loctite 5920. Last time I used the blue hylomar. 

Thoughts appreciated on the stud question.
Oh and Happy New Year

Andy B

[stuartu]

If you are right in assuming that water is coming up the thread of number 3 stud then (since what comes up must also come down) why not use Loctite wicking thread locker 290?

Of course, that might not be a permanent solution.

Regards,

Stuart

[Andy Bennett]

Thanks Stuart
Much appreciated, I wasn't aware of this and have ordered some.

Andy

[Steve Jones]

If you are right in assuming that water is coming up the thread of number 3 stud then (since what comes up must also come down) why not use Loctite wicking thread locker 290?

Of course, that might not be a permanent solution.

Regards,

Stuart

To move the stud, heat it, NOT the block. Take it to dull red and then use a proper stud extractor. I use PTFE tape on the threads to seal them. Of course, Stuart's from Lincolnshire so can afford fancy Loctite products. Those of us in Yorkshire have to be more careful with our money 

Steve

[Andy Bennett]

Thanks Steve
no problem, I would have run the heat down the stud but am still a little concerned that my brazing torch is too much and doesn't have the control. I think I will try the Loctite  first as it is pretty obvious if it has solved the problem or not. 
I too am shall we say, careful, but have splashed out £8 for a pot. 
Having said that I am always open to offers for what's left  

Andy

[John Mason]

Andy, if you can get threats lock down the threads have you tried to get plus gas or similar down the threads to see if you can unscrew ir.

John Mason

[Geoff Halstead]

Sometimes it helps giving the stud/bolt a turn as though to tighten them, thus breaking the rusted threads.
Not always though.

Geoff - Still no heating so relying on portable oil convection heaters.

[Zetomagneto]

Sometimes it helps giving the stud/bolt a turn as though to tighten them, thus breaking the rusted threads.
Not always though.

Geoff - Still no heating so relying on portable oil convection heaters.

If the stud won't unscrew, it even less likely if you have put locktite round it!
290 needs heat to dismantle

[Andy Bennett]

Thanks all
I appreciate that I might be being overcautious about the stud, but I already had one shear off when the last gasket was replaced with the aid of a well respected local expert. He helicoiled it for me.
I just don't want to risk breaking it off, especially as it might just not be the source for the water bubbling around its base.
From my original note I was concerned that some of the nuts felt less tight than others when removing so it might just be that the water was coming from above, in the head,  and finding a route out up the stud. 
I have thoroughly cleaned around the base of the stud and am still waiting for the loctite to arrive so think I will give that a go first as relatively non invasive, before getting brutal with the stud if it still leaks.
Thanks again for all thoughts, much appreciated input.
Andy

[John Mason]

Andy, when all re assembled if you find water still coming up the threads which manifests itself as water around the head studs assuming they are correctly tight. Try a radiator sealant such as Barrs and use it as the makers instructions and you will find it stops small leaks. I did this some years ago with success .

John Mason