If necessary, have to remove two studs that been screwed into iron exhaust
manifold for 17 years so rust had time to set in. This studs mounts the EGR valve. The nuts were removed already.

What is your bag of tricks to deal with this besides the pentranting fluids?

The idea is hopefully not to break them off.

I'm sure you have this same problem on your slant six head studs for the manifolds, bolts that holds both manifold halves together (three bolts) as well as studs or bolts for ones equipped with EGR.

Cheers,

Wizard

PB Blaster and a stud extractor. Vice grips are a pain...

VM

Some folks have luck heating the manifold around the stud with a torch. The idea is to expand the metal around it enough to free the stud. I don't recall if there are enough threads, but you might also be able to spin on two nuts and tighten them against each other. Then try to back the stud out using the inside nut. Doesn't hurt to give the stud a good whack or two on its end (with the nuts on to prevent boogering up the threads) to help break it free. If you do get it to break loose, don't try to take it out all at once. Soak it some more with penetrating oil, and "baby" it out, working back and forth a little at a time, clearing the threads as it goes. If you happen to break it off, make sure you have a center punch, high strength drill bits, and screw extractors on hand, you'll need them.

Good luck,
Jerry

_________________
There's a difference between ignorance and stupidity.
Ignorance is not knowing any better.
Stupidity is knowing, yet doing it anyway.

I've got 2 different heads with broken studs. I really hate that!

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1980 Aspen 225 super six

Uhmmm... The EGR valve mounts to the intake manifold, you may-be looking at the heat riser valve "flap" if you are working with an exhaust manifold.

The suggestion above are good ones, except for "bolt extractor". (easy out) I never use an easy out because the risk of breaking one off in the hole is too high. More on this in a moment.

If there is any "stub" of a bolt remaining, try using that to get it out.
The double nut and heat trick works well. one thing I have done is to screw on the nuts than arch weld them to the stud to keep them from spinning-off. ( the heat from the "zap" also helps fee things up)

If the double nut trick fails, I have a stud removal tool that can get a grip on as little as 1/4 and also a small pipe wrench which can grab onto a small post. Again, heat is a big help.

Some broken studs just will not come-out so fact is, I will not mess with them long before the center punch, drill and tap comes out. Start with a 1/8 drill and then step-up sizes. If you drill on center, out to 1/4 inch, many times you can get a "sleeve' of old threads to come-out by "picking" at the edges or simply retap the hole.
DD

Ditto.

I never had a screw extractor or "easy out" work on anything in my life, so I finally wised up and don't even bother with them anymore. It's a helluva lot easier to drill out a broken stud than it is a tool-hardened screw extractor. They have to be hard to get a grip in the hole, but this same hardness makes them very brittle. Often, it actually takes less to snap it off than it did the old rusty stud or bolt. If you like slant sixes (any old stuff, really), learn to be proficient at drilling out studs as Doc Dodge has explained. The key is patience and drilling on-center, so you may have to "steer" the bit a little. If the stud is broken off jagged, it helps to grind it flat first before punching and drilling if there is any meat left above the surface...

Oh, yeah, I've had surprisingly good luck lately with "PB blaster". Seems to work a lot better than all other penetrants I've tried. I also resort to alternating cycles of heating (with a torch) and cooling with penetrant or WD40. A lot of times it helps work the threads loose. Sometimes, it just requires a combination of things, every situation is different.

By the way, you'd be surprised how well a /6 exhaust manifold will still seal with both end studs snapped in the head. Sometimes it can just wait 'till the offending part can be removed one day to the bench...

D/W

_________________

If it ain't broke, fix it!

Just put the heat right on the stud then try vice grips ... You will be able to feel! if it is going to break off it will feel like it is turning but kinda like it is greased... You can try soaking them good with wd40 or somthing like that then before you start hit them right on the end of the stud with a hammer a few times good and hard. this will help dislodging the rust in the threads.