I wanted to wait till spring to do this but it's too late now, I started. Exhaust stud on #4 is broken below the plane of the head. I can get a regular drill in there. I've got a set of timesert inserts and the tools to put one in. Is there any chance at all I can fix this with the head on? If I pull the head, I'm going to have to have it rebuilt, then I'm going to have to rent a valve adjustment shim set, and buy a bunch of gaskets, why not a timing belt and water pump while I'm in there? and maybe the cam doesn't look so good, and how's that bottom end after 240K? See where I'm going with this?

So I guess I need cobalt? or diamond bits? And they should turn the reverse direction? Does anyone want to talk me out of trying this before I start and tell me to just pull the head and take it to the machine shop? Has anyone sucessfully done this with the head on?

As always, thank you for your help,

Bob
'82 245 turbo

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Bob W.
'91 744T 173K
'82 245Ti 238K
'67 122 wagon

Bob, I've done this before with the Head on. I used a Angle drill. {Millwaukee} I then center punched as needed, used a pilot and then the correct size for the easy out. I used the square one..all the BEST.
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john,,1985, 245:GLTi 246k mi..so.california

If you get to where you have no choice but to pull the head, I'd recommend you get another head from a junk, have it planed at a machine shop, and just swap them. Should save you a lot of downtime, and you can prepare the head more or less at your convenience rather than running around trying to get your repair done in one Sunday afternoon. If you do wind up having to pull your head, it'll be at least a day or two before it's ready to go back on. Besides, the 82 heads had the oiling problem, so a later one ought to eliminate that potential headache.
But as Matt says, you can get this done in the car, if all goes well. It's just tough drilling steel out of aluminum. If it goes off center, it'll be really hard getting it centered again. Good luck!
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total

Bob, I have done this with the head installed with good results. I first used a dremel to grind the head of the stud flat so I had a good place to start drilling. THen I use a center punch, then an actual center drill to get good start in the stud. I did use cobalt drills and they worked very well. Obviously dont forget to swallow as much of the drill bit as possible to prevent breakage. Dont use an easy out, it will break off in the stud, but thats a different story. Keep increasing the drill size until you are big enough to re-tap, or use the good'ole endmill in a hand drill if the hole moves off center. You might as well give it a try... if you screw up you have to pull the head anyway. Good luck and use the right tools!

Matt

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'82 DL - 153k, '93 945 - 102k