Drill bit snapped in exhaust manifold

Osprey6010

Member
 Birmingham - England
Context: replacing the cat on my 2.0i, and had to snap the super rusted bolts off to remove the cat.

Drilling out these bolts has gone fine until this third on. 5mm but went in fine, 5.5mm has snapped about 1mm shy of getting all the way through the bolt. We can't get pliers on the stub of the drill bit left, and was just wondering if anyone has any other suggestions on how to remove them.

I was thinking of maybe removing the exhaust manifold to hammer it back out, but I don't know how easy that will be.

As always any suggestions are much appreciated.
 

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When I have this problem removing hardware from bone, I over-drill with a slightly (0.5-1mm) larger crown drill. I don’t know if that is an option in your case.
 
You need a blow torch ideally Osp, get it cherry red, then throw a mug of water at it, it should come free with some pliers that way. It’s how I do them anyway, works very well.

Best of luck.
 
Unfortunately there's nothing to get pliers on, the bit snapped almost flush with the bolt, and what's left that's sticking out is basically chamfered annoyingly.

Thanks anyway, will keep in mind for the future
 
Maybe use a fine disc or dremel to cut a slot, then unscrew with a flat driver. It's probably not bound tight but broken by a nice sharp bit digging in too quick 🀞should be easy ish to remove. Good LuckπŸ‘
 
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It'll be the back end of that, I would guess. I removed mine just by hitting it with a hammer.

I did cut a small relief in from the edge of the flange with a Dremel to relieve the pressure.

Might be easier than drilling
 
When removing the bolt with a hammer, I assume you just hit it from the front? (where the cat joins the manifold) I've only got axle stands and can quite get the room to hit it hard enough
 
Maybe use a fine disc or dremel to cut a slot, then unscrew with a flat driver. It's probably not bound tight but broken by a nice sharp bit digging in too quick 🀞should be easy ish to remove. Good LuckπŸ‘
Never used a dremel Nick, would the tiny discs be hard enough to slot a drill bit..? Just pure curiosity is all.
 
A thin carborundum disc is plenty tough enough. If my method works then use some penetrating oil and heat on the remains of the stud and using the TriggerFish method, twat it out. If that doesn't work then grind the stump flat to give a safe knocking surface and revert to TriggerFish with a bigger hammer method. If it's Post cat you can remove the rest of the exhaust back and do it on a bench, If pre cat then you need more of everything and loads of patience.
 
Never used a dremel Nick, would the tiny discs be hard enough to slot a drill bit..? Just pure curiosity is all.

I find the fibre ones shatter all the time, but these are much easier/more resilient to use (just find a more ethical supplier than Amazon :) )

When removing the bolt with a hammer, I assume you just hit it from the front? (where the cat joins the manifold) I've only got axle stands and can quite get the room to hit it hard enough

Yeah, hit it from the side where the nut used to be (so from the rear wheels towards the front wheels direction.

I did mine on axle stands - it was hard to get the swings in, but cutting the relief slot helped a bit. I didn't have a blow torch, but suspect heat/quenching would also help as others have suggested.
 
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