Head gasket failure

[Moggie May]

Hi all,
Found a lot of creamy gunge inside the tappet cover so I removed the head and discovered water in cylinder 2&3. However, the gasket did not seem damaged or broken.
When I came to torque the head back down after replacing the gasket, the middle short stud just spun. After further inspection it was clear that whoever worked on it previously had damaged the thread.
So Ok not a huge problem to resolve but on closer inspection there appears to be a hole in the bottom of the stud hole in the block.
Is this normal or has someone been a little too enthusiastic drilling out previously.
Please see attached photos,I would appreciate your feedback.

[svenedin]

Is this the remains of a broken stud that has not been successfully removed in the past? Did they try to drill it out?

[philthehill]

Not to worry - not all head stud holes in the block are blind. Just make sure that you put some sealing compound on the threads so as to stop any coolant migrating up the threads.

[Moggie May]

Well I really don’t know.
Should the stud hole be sealed at the bottom because this looks to be open to the coolant water contained within the block.
My thoughts are that this is how the coolant probably got into the cylinders by escaping up the stud hole and under the head gasket.
I’ve never noticed this before but this is the first time I’ve taken the head off.

[philthehill]

The middle O/S stud hole goes right through to the water jacket so nothing amiss there.
If the threads have gone just fit a Helicoil thread insert. Fit the head and use the head hole as a guide when drilling for the Helicoil.
There may be some old stud left in the stud hole but when you fit the Helicoil insert you can drill out any remains.

[Moggie May]

Thanks everyone for your suggestions/advice I am most appreciative.
DaveB

[kevin s]

The only problem you might come accross is that the stud hole in the head is too small for the larger helicoil drill, if you have a scrap head just drill the hole out in it, if not drilling a hole in a piece of hardwood in a drill press and using that to kerp the drill square works for a one off.