Broken Bolt/EGR Valve
 

As I was attempting to remove the EGR valve off of my Civic Vx, one of the two nuts that holds it down, had broken off of the left stud. The right one however came off without a problem.

Upon first inspection, it appeared has though I could drill this out; but then started to wonder if both of these studs were welded in place.

In closing, it appears to be a part that can be separated; but before I go into any more trouble, I'd to know if that fact can be confirmed. As for now, I have sitting soaked in WD-40 oil for at least tomorrow.

It's not easy but it can be done. You have to drill a hole through the remaining part of the stud, assuming there is not enough to get a pair of vice grips on.
Wd40, heat and impact are your friends.

One of the most important things about extracting broken studs is to try to actually go in the opposite direction first. If your extractor will allow it, Start by rotating it clockwise, just a little bit. Then try backing it out. If it gets very hard, just work it in and out a few times, which I have found helps getting it out.

The real precision work is in drilling it out. If there is any exposed part, after soaking it in the WD40, then hit it with a hammer, not killer hard but with some force. It will help to break the corrosion bond and flatten the surface. Take a punch and give it a divot in the center for your drill bit to get perfectly centered (critical).

Drill slowly using the WE40 to cool the bit and help it cut the metal. You want to drill through the stud completely before attempting extraction.

When I could see better and had more steady hands. I took pride in having the extraced stud look like a tube becasue the drilling was that close to perfect.

If you can't get it to back out, then the next step is to drill it out to the threads and try to pluck them out, or even more and a helicoil. "Helicoil" used to be my wifes favorite nickname for me.

regards
Mech

In terms of going in the opposite direction first, I was wondering if you can tell me if the stud is left hand thread from the top or a right hand thread?

Oil of Wintergreen
 

works good to break up a rusted thread, especially on exhaust flanges, etc. Get a small bottle at local drug store or pharmacy.

Great! Just when I was making progress, the drill bit broke off into the stud. In spite of working the drill slow, along with using cutting oil, I now have a situation where I'm at an apparent stand still.

I just got two colbolt drill bits and some cutting oil. More updates on this later.

Success...I got it out! It took me the better of day; but thankfully, the drill bit had broken off to the right. It took me two titanium drill bits and one colbolt bit; but I was able to drill through. In spite of all of that, the EGR valve was cleaned too.:)