birdmanmt

So i talked to my mechanic about changing the exhaust studs and he says that it's not necessary to pull the head. He's seen a bunch of 5k's with this problem and he's never pulled the head to fix it. Anyone here done it without pulling the head? I'm thinking it'll be easier to just have him do it at this point. His quote is $275 not including parts.

shortyq

It *can* be done without pulling the head, it's not easy, and worth every penny of 275USD, but is a short term fix (read: you'll be back). A right angle drill is necessary minimum, but one also has to be extremely careful that the bore is done level with the head, and that depth is followed exactly. Especially on #1 upper, where too far is hitting the water jacket btst.

IME, I'd rather pull the head for a couple reasons. First, when this happens, the EM itself is usually warped, and either in need of replacement (cracks) or minimally machining. A quick repair of a single stud with manifold on, rarely "cures" the problem. The next weakest stud (usually opposite side of manifold, ie if #1 gets repair, #5 goes next. Also make sure you get the updated longer exhaust studs and use the thick mold washers audi did on the later turbo cars.

HTH

Scott Justusson
QSHIPQ Performance Tuning

rooster 2

good advise from shortyq, could not have said it better

birdmanmt

my mechanic said that he does the machining work. It's not that he just drills the stud that broke, he'll pull the EM and fix the warping in it. Then replace all of the EM studs' and gasket since he's in there. SOunds better than pulling the head, especially for his price.

audijim113

after listening to the spit-spat for a long time, I decided to do the job myself.

getting manifolds and stuff out of the way was the biggest issue. right angle drill is absolutely necessary and a reverse twist drill is too. when you take the intake studs off, make absolutely sure you have the hex driver socket completely into the hex bolts. tap it in to get past any rust, scale or dirt. Otherwise, you might round one of them out and have yet one more thing to drill out.

getting the bore dead center is critical. i made a small jig from steel and bolted it to a nearby good stud. This provided a perfectly centered pilot hole directly over the broken off studd.

after drilling a pilot in the stud, i switched to a reverse twist drill. if you've ever drilled steel, you know that the drill will often "catch" and cause the drill to stop while the chuck turns.

with the reverse twist (and angle drill in reverse too) when it "catches" the stud will back out nicely. get a reverse twist drill at a good industrial supply store.

you can get a set of studs and nuts on ebay for about $30 or so. add the gaskets and a reverse twist drill bit and you've got $50 invested.

good luck.

shortyq

good post, can tell btdt. A couple of issues tho. First, on a turbo car things are tighter than on a non turbo car. Second, many times those studs are in too tight to drill them out. A method I used quite sucessfully (head removed, but could be done insitu) actually is to use a mig welder to weld a tip onto the stud, then remove with vice grips. The quick heat from the welder helped loosen the stud.

I figure the drill method is a good place to start. The worst that happens is you pull the head anyway. I know on an 86 5k N/A car, I just pull the head, btdt. By the time you get the intake off, and mess with the drill, the head could be on the bench. That's a quick job on that motor.

I'll still put forth, that if ALL you do is repair the offending stud, you still have a warped manifold problem.

HTH

Scott Justusson
QSHIPQ Performance Tuning