Introduction: How to Repair Messed Up Cylinder Head Exhaust Stud

A stud broke very deep in the thread so it has to be drilled and tapped to the next size

This happens because I have the cheapest of drills and some garbage drill bits and ended up making a mess I will show you how I fixed it making it look as stock as possible.


Drill(The lower the RPMs can go, the better)

Center Punch

Drill bits(Sharp and quality drill bits are necessary or you could end up like me)


JB Weld Original

Aluminum scrap piece

Step 1: Start Drilling

Punch the broken bolt or stud as centered as possible then grab the correct size drill bit depends on which thread size you need (This chart could be helpful: ) Start drilling as centered as possible until you hit the depth you need, blow the burrs with compressed air and tap it (Don't forget to lube your drill bit and tap)

But if you end up like me you will need some deep aluminum block, drill a hole and tap it to the size you need then cut or grind all around until you get the cylinder shape insert.

Step 2: Mixing the Magic

-Get some JB weld Original (Wouldnt recommend any other), mix it 50/50 and coat the hole and insert all around plenty(Make sure inside the hole and around the insert, it's clean and dry before applying the Jb weld).

-After 24 hours of curing, sand it flush with 200 grit sandpaper and voila!

Step 3: Results

It ended up pretty good I didn't want to thread the JB Weld because it's softer and could strip not sure about it just wanted to be safe than sorry.

Hope it could be helpful, thanks for reading!