I have one exhaust manifold-to-cylinder head stud that is causing me a lot of pain... drilled a hole, tried a screw extractor... extractor tip broke off... re-drilled, but the new hole was slightly off center, cut just a little into the threads. At this point my mind is exhausted. Any suggestions? My last idea is to just leave it like that and seal it with sealant or JB weld. Any chance that'll hold (the other 5 studs are fine)? This car is killing me... slowly.

 

you could drill out the rest of the threads and tap new, larger ones?

 

That's probably the sensible thing to do. And then just bolt it down with something from homedepot? Should I add a washer? I'm kind of scared the bolt won't take the heat and cold, though. Especially during the winter. Think it'll be okay?

I'll probably have to do the same to the exhaust manifold-to-downpipe studs. It's just the temperature fluctuations i'm worried about.

 

as long as the metals are the same you'll be fine. Because they will expand and contract at the same rate.

 

Man, I'm not really sure how to tell. I'm guessing the heads are steel?... probably too heavy to be aluminum. But does anyone know for sure? I don't even know where to find aluminum studs...

 

Before you try making it larger you might want to make sure the bolt size is going to fit thru the manifold hole. Also use a bolt that is of the same material as the ones already being used.


As for the head itself, it is Aluminum Alloy. The block is Iron.

 

quick way to tell is use a magnet if it sticks it's steel of some sort, if it doesn't it's aluminum. there are other metals that are magnetic and not magnetic but steel and aluminum are the most widely used in the automotive industry for bolts/studs/fasteners.

Is the block out of the car? if so you could try heating up the area around the stud, not glowing but just hot. also try some penetrating oil