Wrenchin... Adventures under the hood... Put em here.

[The Reverend Floater]

Thanks. I've been googling and reading up on bolt extraction. I was using oil for lubricant while drilling (PB Blaster, it was handy), but I think I was drilling at too fast a speed. And I think my general use drill bits aren't good enough.

Is it worth heating the area with a torch? I have a propane torch I can use, and it's a heat safe area (exhaust manifold).

If I damage the threads while drilling, I have taps so I can chase the threads clean. At worst, I could put a bolt through the hole and use a nut on the back side.

I've found that the combo of PB and a torch does help. Any possibility of welding something to the broken bolt for leverage?

[Obstruction]

Slow speed, lubricant, corded drill (more torque) copious cussing, cobalt and carbide help. It pays to have new sharp spare bits handy.

As noted above start with a small bit and work your way up.

[El Chupacabra]

I've found that the combo of PB and a torch does help. Any possibility of welding something to the broken bolt for leverage?

My neighbor has a welder - but it's a very small stub on the backside of the broken bolt, and access is tight there. So, not likely.

[El Chupacabra]

Slow speed, lubricant, corded drill (more torque) copious cussing, cobalt and carbide help. It pays to have new sharp spare bits handy.

As noted above start with a small bit and work your way up.

I was using a cordless drill - but I don't think my lack of progress in drilling was due to drill torque. I do have a corded drill, and I think it'll fit too.

[basinbeater]

You hit with pb blaster already, but get a punch centered on the remaining stud (in the drill recess you created) and nail it with a hammer. That can shock bonds with corrosion free and help the penetrating oil really do its job. If I even look at a bolt that I think is going to be a hard time, I give it a whack and then soak with penetrating oil.

sent from Utah.

[El Chupacabra]

You hit with pb blaster already, but get a punch centered on the remaining stud (in the drill recess you created) and nail it with a hammer. That can shock bonds with corrosion free and help the penetrating oil really do its job. If I even look at a bolt that I think is going to be a hard time, I give it a whack and then soak with penetrating oil.

sent from Utah.

I'll give it a try. I drilled at it a bit more this morning, got new bits from the neighbor (has big shop full of machinery and equipment) including left hand bits. Put it aside for awhile, went on to the rest of the project.

Intake manifold is out, taking lunch break now, then will go clean stuff before reassembling. PITA to disconnect the fuel injector connectors, and the fuel lines themselves were a struggle to separate, even with the disconnect tools.

The last pic below is of the EGR connection on the exhaust manifold, with the lower bolt broken off inside. I have reasonably good access to the front (the camera angle side) to fit a drill in place.

[fatnslow]

I'll give it a try. I drilled at it a bit more this morning, got new bits from the neighbor (has big shop full of machinery and equipment) including left hand bits. Put it aside for awhile, went on to the rest of the project.

Intake manifold is out, taking lunch break now, then will go clean stuff before reassembling. PITA to disconnect the fuel injector connectors, and the fuel lines themselves were a struggle to separate, even with the disconnect tools.

The last pic below is of the EGR connection on the exhaust manifold, with the lower bolt broken off inside. I have reasonably good access to the front (the camera angle side) to fit a drill in place.

You might consider buying a few brand new metal bits(small) and start a nice pilot hole to work off. That brand new metal bit can save you quite a bit of grief.
X2 on the center punch for a decent recessed spot to start drilling.

[refried]

I can see you're already off center, that's going to make it a little harder.
Return your neighbors' bits and go buy a pack of 5- 1/8" bits, a couple 3/16". and a couple 1/4" bits. start with the 1/8" bit and drill at a slow speed and let it cut, you can speed up as necessary but not too fast. When you're thru start the 3/16" and see if it hits the threads, if it's not cutting them out completely drill thru again being careful not to break the bit when it cuts thru. try to move it with a sharp chisel or punch, if not try the 1/4" bit but you're off center so you're going to loose some threads. Cut a little and see if it spins. Sometimes you get lucky and it will let you reverse it out with the drill.

[The Reverend Floater]

I can see you're already off center, that's going to make it a little harder.
Return your neighbors' bits and go buy a pack of 5- 1/8" bits, a couple 3/16". and a couple 1/4" bits. start with the 1/8" bit and drill at a slow speed and let it cut, you can speed up as necessary but not too fast. When you're thru start the 3/16" and see if it hits the threads, if it's not cutting them out completely drill thru again being careful not to break the bit when it cuts thru. try to move it with a sharp chisel or punch, if not try the 1/4" bit but you're off center so you're going to loose some threads. Cut a little and see if it spins. Sometimes you get lucky and it will let you reverse it out with the drill.

Agreed. Be sure to use cutting oil or some sort of lubricant. Just dip the bit frequently. Makes a huge difference.

[El Chupacabra]

You might consider buying a few brand new metal bits(small) and start a nice pilot hole to work off. That brand new metal bit can save you quite a bit of grief.
X2 on the center punch for a decent recessed spot to start drilling.

Are there metal specific drill bits?

I didn't get back to the drilling today. I finished up the rest of the work - knock sensors, harness, bunch of gaskets, everything cleaned up and reassembled. Only thing left is to get that bolt drilled out.

Are any Dremel attachments useful for this? I have a lot of bits for the Dremel, but I don't know how well the conical grinding stones would work on metal.

I do have cutting oil lubricant and am using it.

[warthog]

Dewalt makes some nice carbide bits that cut through bolts like butter.

[basinbeater]

I can see the future.



sent from Utah.

[El Chupacabra]

Dewalt makes some nice carbide bits that cut through bolts like butter.

Thanks. I read that carbide bits are brittle - concern about breaking off the bit in the hole valid, or don't worry about it?

I won't need to helicoil this, even if I destroy the threads in the hole. I can just run a bolt through the hole and put a nut on the back side.

[Todd Zander]

Carbide center drill bit wont break, its what they use to break through case hardened layers and drill through broken taps.

You dont need that though, next time flatten the exposed stud with a dremel and center punch a starter dimple as centered as you can get it.

[warthog]

Yup- I broke a hardened steel left hand bit off trying to get a header bolt out. Nightmare.
I ended up grinding it all flat and then notching the clamp in a different area- just drilled a new hole and through bolted the clamp. Oh, that and tons of red gasket maker for good measure. It never made a peep since.

[refried]

If a torch isn't available, acetylene, not propane or Map (Map gas isn't what it once was and burns much cooler than the real Map gas) , the easiest way to remove a broken bit is to break it into smaller pieces with a punch. Get a pin punch that will fit into the hole and beat the broken bit into small pieces with a big hammer and remove them with a magnet. Don't break the punch in there, it happens and doesn't help the problem.

[detuned]

Are any Dremel attachments useful for this?

little late to the party

can tell from the pic that you are pretty much beyond drilling, if i were at the point you are now i'd grind the existing remnants flush with the mounting surface then use a rounded tip burr like this:

https://www.amazon.com/Heavy-Duty-Ro.../dp/B000GLNEJM

gently remove material until you have an even divot that you can center punch and continue drilling into the cleaned up stud material

an air powered die grinder works best but can be done with a drill or dremel tool

good luck

[El Chupacabra]

If a torch isn't available, acetylene, not propane or Map (Map gas isn't what it once was and burns much cooler than the real Map gas) , the easiest way to remove a broken bit is to break it into smaller pieces with a punch. Get a pin punch that will fit into the hole and beat the broken bit into small pieces with a big hammer and remove them with a magnet. Don't break the punch in there, it happens and doesn't help the problem.

I don't have space down in the engine bay to swing a hammer enough to break up that bolt stub. There's space to tap and center punch - it's just big enough to fit a drill.

[fatnslow]

I don't have space down in the engine bay to swing a hammer enough to break up that bolt stub. There's space to tap and center punch - it's just big enough to fit a drill.

Don't worry, just a little bite from new bits is what your after. When you get it started rest will be much easier. If your unsure put a bolt on a big vice, break head and practice to get the feel.

[El Chupacabra]

little late to the party

can tell from the pic that you are pretty much beyond drilling, if i were at the point you are now i'd grind the existing remnants flush with the mounting surface then use a rounded tip burr like this:

https://www.amazon.com/Heavy-Duty-Ro.../dp/B000GLNEJM

gently remove material until you have an even divot that you can center punch and continue drilling into the cleaned up stud material

an air powered die grinder works best but can be done with a drill or dremel tool

good luck

I have Dremel tips like the one linked. I may have an air die grinder, but I think it's a little too long to fit in the work space.

I can't grind the remnant flush with the flange surface - the broken stub is recessed into the flange.

Why is this "beyond drilling" based on the photo?

[Todd Zander]

You need a large (3/4-1”) countersink bit to remove the leading eff’ed up edge of the bolt remains.

[detuned]

Why is this "beyond drilling" based on the photo?

should have said "in the current situation"

as stated earlier you're off center with the drilling right now

just my .02 as to what has worked for me in the past -- ymmv

[warthog]

I think he means that if you keep drilling in the direction it has wandered, you will be learning a new skill soon- helicoil install, or thread tapping.

The idea is to drill it out in concentrically larger and larger increments unit the old threads basically crumble out. If you aren't dead center to start, that becomes really hard to achieve.

[El Chupacabra]

Got it.

As long as I can drill through, I can put a bolt and nut through to hold the EGR pipe to the manifold. It is a through hole, not a blind hole, so it doesn't matter if I damage the threads.

This is not like a bolt going through the manifold and into the engine block, which would be a blind hole.

[warthog]

Ahh- same problem I ran into. Red high temp gasket maker is your friend.
Like I said before, never made a peep since I rigged it about 7 years ago.