Best method for extracting snapped valve cover bolt

[DVJ38]

Ya, a snapped valve cover bolt. I'm pissed. The one time I decide to actually torque something the wrench was wrong. So now half of the bolt is sticking out of the head. I was going to try to put 2 nuts on it and put a wrench of the bottom one in hopes it would bring out the stud, but there is only just barely more than a nuts width out of the head. So I don't have a whole lot to work with. I really don't want to risk messing up the head getting it out.

My thoughts are:
1. Grind down 2 nuts to like half thickness to try that method. At least it wont damage the snapped bolt more, even if it doesn't work.
2. Use one of these to drill a hole in the middle (after punching a small dimple in the middle to make sure it's centered) of the snapped bolt and pound the fluted extractor in and twist it out using a tap holder. http://www.lowes.com/pd_574512-281-...L=?Ns=p_product_qty_sales_dollar|1&facetInfo=
3. One of these kits with the counter-clockwise cutting bit to try to pull it out. Then if it doesn't work I can drill a little hole in it then use the fluted extractor to try to twist it out: http://www.sears.com/craftsman-7-pc...p-00952157000P?prdNo=1&blockNo=1&blockType=G1

The bolt size is an M6 X 1.0 IIRC. I already bought the nuts to try and they fit on another non broken bolt.

On a positive note though, check out how clean it is in there with 125,000 miles on it lol

I don't want to mess this up guys lol.

Thanks.

 

[Martin6107]

If there is any bolt sticking up you should be able to get a vice grips on it enough to back it off.

 

[Tabres]

If there is any bolt sticking up you should be able to get a vice grips on it enough to back it off.

Yeah, if you have enough thread to get a nut on it I would just wind it out with a pair of vice grips. Push came to shove I would just remove the valve cover and then the bolt. That should give you more than enough length to get some vice grips on the broken bolt.

 

[PSUCOBRA96]

How tight is it, a screw extractor set might get just enough bite to get it to move out enough to get a pair of vice grips on it.

 

[MustangMatt77]

If all else fails and you have access to a wire feed welder, put a nut on it, about 1/2-3/4 threaded on it, fill in the hole part of the nut that isn't threaded with wire feed weld, let it cool, soak the threaded part going into the head with penetrating oil, then back it out slowly.

 

[DVJ38]

Thanks for the suggestions guys. The bolt isn't sticking out of the valve cover at all but when I peeked under it I could tell only one nut would fit on. So ya I have to remove the cover first. My car is in a storage unit so I'm unable to put a welder to use, but good suggestion Matt.

Not sure how tight it's in there, but apparently a lot more than 23-29 ft lbs since the torque wrench is broken! Almost threw that thing across the parking lot lol. I may try to grind down the 2 nuts to try that first, then if that doesn't work vise grips, then a different method I guess.

Which one is better though, using that counter-clockwise bit that digs into the bolt and pulls it out as it cuts into it, or drilling a hold in the middle of the bolt and using one of those flute type extractors in a tap handle? Can't say I've broken a lot of bolts in my life...

 

[1997Cobra]

If you broke it by tightening it too much, all the effort you put into it would be released because the head broke off. It should come out by very easily by hand. Unless you bottomed the bolt out in the hole.