Small Engine Repair: Broken Bolts & Extraction
10 posts across 3 communities since Jun 2026; 80% from r/MechanicAdvice.
“I tried extractor kits, those mostly just broke off. I've been drilling it with cobalt bits and seemed to have created a channel down to the botoom of the tapped hole, but I still can get the remaining bit to spin. I have used heat and ATF/acetone, PB blaster, etc. I'm starting…”
“That’s the way I do it. [re: Is this the right way to repair broken bolt slot?]”
“I snapped a rusty bolt off in the manifold. There's a nut on the back that the internet is saying is welded on. I drilled through the bolt but it's still rusted and stuck on. This is a 2003 Honda Element. I'm changing the catalytic converter. Any help would be appreciated…”
Users are struggling with broken head bolts on small engines, particularly carburetors. Common issues include extractor bits breaking and needing creative solutions like welding to remove the remnants. Many posts seek advice on extraction techniques.
SOURCES (21)
“I tried extractor kits, those mostly just broke off. I've been drilling it with cobalt bits and seemed to have created a channel down to the botoom of the tapped hole, but I still can get the remaining bit to spin. I have used heat…”
“I snapped a rusty bolt off in the manifold. There's a nut on the back that the internet is saying is welded on. I drilled through the bolt but it's still rusted and stuck on. This is a 2003 Honda Element. I'm changing the catalytic converter. Any help would be appreciated. Serious comments only. Edit: thank you for the fast advice. The only problem now is how to get the tools such as a chisel and hammer (or a drill) actually IN there lol. It's a really tight squeeze. 2nd edit: so”
“Broke an M6×1.0 valve-cover bolt in the aluminum head on my 2016 BMW x3 n20 engine. I tried using left-hand drill bits and extractors. Now I got an off-center 5/32" hollow steel shell that still refuses to come out. Am I cooked? The YouTube vids make it look easy but I already spent hours trying to get one bolt out. What should I do to remove it? submitted by /u/Jonx1000 [link] [comments]”
“And is it safe to drive to a shop? The other seven crossmember bolts are torque properly. And is there any specific type of extractor you’d recommend? submitted by /u/thankwow [link] [comments]”
“I rounded the last bolt on my water pump. The space is too tight to get a socket or a closed ended spanner on it. Any suggestions to extract it? Cheers 2006 2.5L T30 X-Trail submitted by /u/Technical-Hour9936 [link] [comments]”
“This is the same method I use, but I never thought about super glue for the washer. I've had a lot of success with this method on heavy equipment as well (Excavators, Street sweepers, etc.).”
“I like using left handed drill bits when extractors aren't working. Basically, I drill out the hole with a bit, then get a slightly larger one and drill it further, typically the left handed bits end up grabbing and extracting the bolt.”
“Not into that broken extractor they won't. Maybe left hand diamond drill bits...”
“I read you keep recommending the hardest way to remove a broken bolt, and then talk about using a left handed cobalt drill bit for the extractor. Waste of time. Put a nut with a hole the size of the broken bolt and weld inside of it. Wait a couple seconds to cool and start loosing and tightening until it moves smoothly. If it's a cast head you use a copper tube to prevent the weld from attaching to the head. If you do it so often then you should know it's the easiest way to go. I wouldn&”
“Just went thru this a few weeks ago, under guidance of a very smart retired neighbor, I rigged up this onan to fit under a drill press, he milled it flat, drilled it out & the bolt came out with a good quality extractor. I gotta keep hanging out with this guy - so much knowledge https://preview.redd.it/vbd”
“I have a sacrificial bucket of rusty pittsburgh sockets for this. It's helpful for getting some space away from the weld”
“You're supposed to use reverse drill bits before the extractor, but in this aluminum you can just weld a nut to it and the heat makes it come out like butter.”
“Put a flat washer down and mug welding a nut to the bolt. Baste the heat right to it, hit it with PB Blaster, and spin it out with a socket”
“I've had luck before with using a dremel to cut a notch so I can turn the bolt with a flat head screwdriver.”
“I, center point chisel, start drilling with small bit going gradually bigger , when hole big enough insert easy out hammer it in nice and easy , remove broken piece. if not bugging, if you have a small torch heating it up could help.”
“This is the way. Get a tungsten caride bit and start working in the center. You do not need to remove the entire broken extractor. Just create another hole for another extractor. Lube the broken thread part and c take your time. You will get it out!”
“Best method is to 'weld a nut' to it. You might not have the tools, but the next guy might. I have a reliable method I use for getting broken exhaust manifold bolts out. Clean thoroughly with a wire brush and wipe with acetone/brake cleaner. Take a washer and superglue it to the casting, lining up the hole. Ground to the head and weld the bolt to the washer. Then weld the nut to the washer. Hit it with a center punch while its still hot and turn a little.”