I was doing the requisite tune up on my new 940 and I've found a busted off exhaust manifold stud on the topside of #4. hiding behind the plug wires.

It appears to have been gone for a long time, why no exhaust leak?
I really don't want to pull the head yet, I've read about building up a weld and then backing the stud out, what should be unhooked to keep electronics from negatively reacting to all the stray voltages from the welding?
lastly, what's the down side to driving around until the exhaust starts to make that annoying popping sound?

 

I just noticed my number 1 cylinder exhaust stud was missing a couple weeks ago....Nothing will happend, so I would worry about it.

 

Someday it will need to be drilled out. Meanwhile don't worry about it.

 

Yeah, unless you have a need for pulling that manifold out OR you hear a leak, then let it be..................... BTW, how's the new ride?

 

125k miles and rides like new, whisper quiet, great creature comforts and classic styling. What's not to like?

and I'm still looking for a '95 with low miles and a sunroof.

Thanks for asking

 

I'd fix it, but I wouldn't get upset about doing it right away. I have seen exhaust manifolds that weren't leaking start after a while when a stud/bolt wasnot replaced as teh manifold warped.
It's not a hard job, I had one on a Nissan that I just kept hitting with penetrating oil over about a month and I was able to remove it very easily with a small drill bit (like 1/8th) and an easy out.
Teh trick is to start soaking it in lube now. Soak all the nuts/studs in oil too, makes the job very easy when you get around to it.
All you'll need for teh job is a new exhaust manifold gasket and a stud (get a few though).

Regards, Andrew.