Easy-outs don't remove seized broken bolts! Easy-outs break off in seized bolts!

A picture of what's left might help for advice.

Is there a millimeter or two sticking up? Or is it broken off down in the hole?

If there's a little bit sticking up, you might be able to cut a slot in the part sticking up. Again, intense heat helps, and wax/lube.

I had three broken bolts, two on my lower manifold and one on the throttle body. One had enough sticking up to weld a nut on, and that came right out. The other two, I cut slots in with a Dremel tool cutting wheel. Then I used a MAP gas torch and heated those up to red/orange hot, and applied wax for lube. Then, I heated again, and I used a screw driver bit in an "impact driver" and they came right out.

Lower manifolds are available fairly cheaply. Check the local pull your own parts yards, or check Car-Part.com--Used Auto Parts Market Compare that with what a machine shop will charge to repair the broken bolt.

If you decide to drill, a drill press is almost a must, and plan to drill the whole thing out and helicoil the hole. If the remaining part of the bolt starts turning, you can then use an easy-out to get it out, but if it doesn't move for a drill bit, an easy out usually won't help. With a hand-held drill, you have to be very, very careful to keep the bit straight. If you don't, the bit will break off, and when you break off a drill bit or an easy-out, you're going to need another lower manifold anyway.

 

Ohhhh.
The bolt is about a millimeter down in the hole. I post a picture tomorrow if thatd help. I'm wondering if theres any tool that could cut a slot in it, even with the bolt being slightly down the hole. Replacing the lower intake manifold sounds pretty scary to me... although ill feel like quite a pro if I do manage to replace it! Hahaha

 

Try to drill the bolt out slowly, with lots of WD-40 while drilling to avoid overheating and breaking the bit. Start with a smaller bit and then step up to one that is a little smaller than the broken bolt. Usually while drilling the bolt might break loose. It really works well if you have a set of reverse drill bits.

 

This is what the screw looks like. Theres a lot of blackish-yellowish crud on it. The same stuff that was leaking from the upper intake manifold in the spot where the broken screw is (probably not a coincidence lol)

 

IMO, that lower intake should be replaced. Lower intakes for this engine are all over the place, and inexpensive ($25 + shipping at Car-Part.com--Used Auto Parts Market ).

If you have a drill press, and you don't value your time much, you could try drilling it out for a Heli-coil. Clamp the lower manifold down on your drill press to be sure you're drilling straight. I'd start with a 3/32" cobalt drill bit, step up first to a 3/16 cobalt bit, and then up to whatever cobalt drill bit size (1/4" IIRC) the Heli-coil kit specifies for the m6x1.0 Heli-coil tap. Go slow, use lots of drilling/cutting oil.

It would probably cost more for a machine shop to Heli-coil that hole than you would pay for a used lower manifold. The Heli-coil kit might cost as much or more than another used lower manifold.