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[DanielF]

Just discoverd that one of the exhaust manifold studs on my Omega are broken, and I can hear there are a leak when I rev up the engine.
I can see that the previous owner have tried to drill it out, but not been able to make the hole in the stud in the center.
Do I need to take the cylinder head off, or is it possible to drill / grind it out when mounted in the car?
If I need to take the head out, is it any how-to guides on the forum or online?
Thanks for all help:)
Daniel

[Seth]

I made-up a sleeve that fitted snugly into the manifold flange.
This had a 1/8th" hole drilled centrally thro' it.
Fitted a 1/8th" drill bit into a right-angled drill, and drilled into the broken stud about 1/4"
Inserted an 'easy-out' and voila! - the broken stud unwound from the head.
Don't drill more than about 1/4" as you could drill into a water-jacket within the head.

[Shagma]

I'll tell you this...
Dont mess up the hole like I did! It will keep you busy for a long time, and it will most certainly cause you lots of swearing...
However, I have a few advices for you...
As Daniel here is saying, its a good idea to make a center with the manifold hole.
Or what I did, (after I trashed the hole), put the manifold in a small platform drilling machine. Drill through the manifold hole and a flat steel plate dim about 35x12 with a 12mm drill. for each hole you drill punch in a 12x2mm pipe working as a guide pin. You dont have to drill all the holes. At the hole where the stud is broken, drill with 12mm to get a center.. then continue with a smaller drill, about 5mm.
Then tighten up the flat steel againt the cyl head, make adjustment to fit aprox the center of the stud.This was you will keep the drill steady and in center while drilling.
The thicker the flat steel is, the more guiding you will obtain during drilling...  It took me a couple of hours the get the materials and do the job, but this gives me a excelent start for a good result.

You can also use the manifold for guiding, but this will reduce the visual insight and of course it will not provide you the optimal center.

Did this make any sense to you?

[DanielF]

Yes, thanks I'll try to use the trick with the flat steel. Were you able to drill the studs out with the cylinder head still in the car or did you have to take it out? It's not much space around the manifold........

[Shagma]

Its not an easy task, but it is without doubt the easiest and cheapest way to do it... Be VERY sure to hit center before starting drilling.. and.. do NOT brake the drill;) use a 5 or 6 mm drill...
and you certainly need a angle drill!!