Replaced passenger side manifold on a 2004 F250 5.4l Superduty exhaust manifold. Soaked studs for a week in PB Blaster & Kroil and a day of ATF/Ace. Got all but one out that snapped when using a stud remover. Shux...I busted out a drill and picked up an 8x1.25 tap to drill & chase after. Well got it going pretty well and I got lazy & tried to speed up things, after a few drill bits up and through I busted out a extractor...MISTAKE!!! knew I should have just drilled it as the extractor snapped with an inch or so up in the hole. Well 5 Dremel Carbide bits later and half of it is grinded out but the Dremel jumped around more than a few times and the hole is all screwed up not to mention threads, out of center, (tried reaching while engine still in to do this and in a semi-blind spot).... Am I good to drill and tap to 7/16, 10mm or even 11/12mm on the rear most top exhaust manifold stud depending on how bad it is once I get it?? That's how bad the heads are screwed up & off center. Ordered a template to assure a straight drill & tap from here on out or would I be cutting in close to anything important? HELP...can I salvage or should I just say F-it and bite the bullet to get a new head. If I can retap larger without any damage or water leaks I prefer that

 

Happy new year?

 

I would look into a helicoil kit. Should be plenty of room between the screw hole and exhaust outlet. That would be my first choice before a new head.

 

The first 1/2 inch or so of the hole is pretty mangled...a Helicoil wouldn't work unless I enlarged the hole anyways that's why I was thinking of just running a 10mm or so in it. I may be able to save the last 1/2 of the threads for the original stud size..not sure if that's enough grip/turns in to suffice though? In any event its pretty messed up from letting my anger get the best of me when trying to remove the easy out and ramming the Dremel in in a fury and demolishing a lot of the outer hole. From my perspective its so enlarged in the first half the stud hole it will have to be drilled larger or filled in with something far as I can tell. Just wondering if drilling that large that far in is putting anything in danger. Maybe I'm missing something as I'm not too pronounced with the 5.4 but if you could seeI can fit a 10mm bolt in for 1/4inch or so before the stud hole goes back to being original sized if this makes sense

 

Had same thing with mine, one of the studs snapped off below the surface I got the welder and built up a bead on the broken stud then welded a nut onto that and it came straight out

 

Another option is Keensert. They are similar to helicoil. Only the body is solid. Rather than a spiral. They won't come out.

 

keensert.... or remove head .. take to machine shop..

most likely weld area closed.. and start over.. drill and tap.. straight and true...

cheaper then a new head.

 

At work I had to remove the heads off a Chevy truck due too this, they had to weld off the hole and retap and helicoil it, they did a great job. Your only option at this point is to remove the head and get if fixed or get another head without broken studs.

 

As Chuck's First Ford said, you can remove the head & have the extractor removed & have it plasma arced & repaired or use a thread insert. Check out this link from McMaster-Carr scroll down for the metric thread section. you don't need the installation tool. I just used a flat blade screwdriver to turn mine in. https://www.mcmaster.com/#standard-t...serts/=15q1gnl McMaster-Carr is mail order & it will be on your door step in a couple of days.

 

I've decided I'm not going to pull it...I'm going to drill and retap tp 10mm unless someone says it'll hurt anything??? If so than than I'll just face the reality that I'm just missing an Exhaust stud on the backside. Either way it'll be better than what it was...had about 3 holes the size of Dimes on the manifold before and all studs were rusted. Got the SS studs and a new manifold.

 

Save your sanity, pull the head off and take it to a machine shop. Let them get you fixed up and it probably won't cost much at all.

 

A heli coil is bigger. You will have to drill almost 10 mm prob 9.5...I would do a 8mm heli coil or another type of insert....Dont go too deep is all. I had 4 or 5 break on mine... I welded on them to get em out... 24 hours in the wheel well.

 

Ok down to the last 1/8th inch of the extractor.....Long long process grinding this thing out never using an extractor on anything besides screws from now on! .It may need 10 or 11mm with how enlarged the first 1/4 inch of the stud opening is though...idk Ive never used a helicoil. If its gotta be 10mm anyway any bad results from just running a tap and putting in a 10mm to save on buying a helicoil. The flange on the replacement manifold wouldn't need to be drilled out any there's 1/8th inch or more of space around the 8mm stock stud hole on it. Wouldn't all match and not sure if the clearance on the manifold stud hole is for clearance from expansion or anything though.

 

I'm pretty set on just drilling and tapping to 10mm....just need to know if ill damage anything or if I should only go 1/2 way in to be safe etc

 

I will say.. you replaced other studs on this head???

so you can tell just how deep you can go.. look at the old studs

going to deep OR going off angle.. can turn that head in to trash.