Spark plug change.. secondary Air Injection Tube stud broke

Oh, yeah you can... There's broke and there's made it worse broke...

 

Weld a washer to it
then weld a nut to the washer
then put a wrench on the nut and it will come out easy

 

Almost precisely the same thing happened on mine, except the rear/upper 10 mm nut came off all right.

Driver's side, lower one. Sheared off precisely the same and I had pre-treated the stud and nut with the usual stuff.

Someone asked if there's a nut behind the flange - no, the stud is just set in the flange.

What I did was, reinstall the upper thingie at the good end, (for bit alignment purposes) then drill out the stud. I had a nut, washers and bolt in my junk box (which happened to be Imperial but OK). I used some of that cherry red Anaerobic sealant, just to be on the safe side.

Just wish I had installed new Ignition Coils right then and there - I've got to do that soon.

I wonder what is getting on this hardware - or did the connection get corroded in large part because of the proximity to the manifold.

Note: Change plugs often, then the connection will not get a chance to corrode so much. Salt on Roads? Clean and protect this hardware.

You will need an articulating "snake" adapter to get your drill/driver in a good spot to drill out the busted stud.

 

That thought never left my mind, until I was almost done!

+

Oh, btw, the repair has 10,000 miles on it - no codes.

 

This is why i anti seize everything. Drill baby drill. Get good drill bits and don't break any. Start small and work your way up, will most likely come out before damaging the threads.

 

Well, persistence prevails. Cut the stud flat with the flange, and drilled it out with a set of hex bits from Amazon (superb quality!) and using a 12” hex bit extension. Could have probably re-taped the threads but opted for just a bolt and nylon lock washer (replaced the one after taking the photo). Drilled it out to 1/4” and then installed a M6x30 bolt with washer and lock nut.

 

Good job! But I don’t think you should be using a nylon locking hardware. It will probably melt due to high exhaust temperatures. I’m not sure where you would source it but, in aviation, there are stainless lock nuts available that do not rely on a nylon insert. These are used on engines and other areas that are exposed to high temperatures.

 

Well done sir. I concur, nyloc is not the best on your application.

 

@TheSponge if you don't have a source for an aviation grade steel self-locking nut, let me know. It won't be metric threads though, so you will need a 1/4-28 threads per inch bolt to go with the nut.