Hi all,

Went in for an oil change today. Tech came over to me and showed me what was left of a manifold bolt. Apparently it broke from the head and it was wedged in between the heat shield. My question is what is the best way to fix this problem. I know how to take the manifold off to replace the gasket, but what if the bolt is snapped from the head. How do I get this out without damaging the head? Is there a special tool? Also, what size is the bolt and length as well as torque spec's. One last question. How long can I drive with only 7 bolts. Car runs fine and smooth. Will I damage anything. I just had the head gasket replaced 6 months ago.
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Regards Chris, '92 745 thats nearing 170K.

I see two scenarios:

A) the bolt, having been overtightened and broken off is no longer under tension, and all you need to do is Dremmel a slot in the end and unthread it with a flathead screwdriver.

B)The bolt &/or threads are buggered. You will need to remove the manifold(not bad on nonturbo) and work on teh bolt. I get out my trudty Vice-Grips, and hold a fair sized nut and washer over the broken head of the stud, and weld through the center of the nut onto the broken stud with my portable MIG welder. The heat of the weld frees the threads up, stick your waiting Impact or ratchet on the nut right away (Use all your fire safety precaution or the nut will leave a mark!). I have agood-excelent sucess rate with this technique. You might have to Heli-Coil the bolt hole, but that is easy compared to E-Z outing.

Good luck.

Thanks for the information everyone. This really sucks because i just replaced the head gasket 6 months ago. Isn't there a tool that I can buy to get that bolt out if it's flush to the head. I'm trying not to have to take the head off. Very expensive and I'll sell the car before that happens. Some say an ez out in not good to use. I thought that was a tool to release to bolt?
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Regards Chris, '92 745 thats nearing 170K.

I'll add some to Art's comments. I once took out a snapped stud in a Dodge V-8 head. I was lucky and it worked but I think I used up my lifetime supply of EZout luck. If that EZout bit breaks, it is too hard to drill out and it really takes a machine shop after that. I have had reverse drills recommended. These are drill bits which drill in the reverse direction (requires a reversable drill of course). As you drill out successively larger holes in the broken stud, the stud will release and unscrew at some point.

The trick, whether you use EZout bits or reverse drill bits is to center the drilling in the broken stud. What I would do is remove the exhaust manifold and use a tool like a Dremel to grind the face of the broken drill flat. Then carefully make a dimple in the center of the stud with a punch, then do the drilling.

Good luck! this is really a PITA

If you are lucky, the ez-out screw extractor attempt is just a ritual you go through before drilling the stud for a heli-coil or time-sert. To be lucky like that, you have to know by experience and feel what it takes to break the hardened screw extractor and not exceed that. If you haven't endured the pain of breaking one, don't push your luck and skip the extractor step; just drill to the spec for the insert's tap, and put all your energy into keeping the successive drillings centered in the stud. If an ez-out ever worked on an 8mm aluminum head exhaust stud, I've yet to hear the anecdote. Depending on which stud is broken, a good right-angle drill may be useful to keep the head in the car. A good drill motor is necessary for low speed control.
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Art Benstein near Baltimore

This is one of those excruciating problems that is so small and yet can leave you so stuck...
Nearing 170k and the mathematics of aluminum and steel expantion ratios lead to the inevitable conclusion that your headgasket is probably nearing the end of its replacement cycle anyhow. Let a good machine shop get the stud out for you, and rework the head at the same time. If you're running well now a HG change will certainly not detract from that, and it is a great chance to fudge around with some other stuff that is most easily accessed with the head off.
Cleaning up the top end before any major symptoms appear is a super way to promote the longevity of your engine. Consider it an investment in the future.

Shifted
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'87 745t 214,000; '93 Toyota MkII; '73 Suzuki Jimny (Brute) LJ20 360cc

Your exhaust manifold gasket will fail. See the 700/900 FAQ for detailed tips on solving this problem. Do NOT use an "Eeze-Out": they are guaranteed to break off and cause a massive problem.

chris
if the stud broke off flush with the head you can try to use an easy out to see if you can get it to release but your chances slim to none that it will work. your pretty much screwed if it broke off flush and youll probly want to take the head to machine shop to get it out. if there is some of it sticking out you can try to get it to release with vise grips. good luck

Try a 90 degree drill, drill deep enough into the bolt to fit an ez-out. I may have the same problem on
an 88 760 or else the gasket is blown.

gary