Sheared off bolt...

Sindri

Sindri

Sindri

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7 Jul 2009
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599
Car developed a misfire last night and I noticed coilpack 2 was sitting higher than the others. While it was dark I just presumed that somehow the bolt had come loose as I couldn't see it and I would just need to get hold of a replacement.

Fast forward to this morning and now that it's light I can see that the bolt has sheared off, I guess when the sparkplugs got changed a while back they must have over tightened it.

Any ideas on how to get this out? Or how much a garage is likely to bend me over to sort this out?
 
Take it to an independent garage, ask them to do an oil change it something that is due. Will take them minutes to sort it. Probably no charge.
 
When you remove the coilpack has it sheared flush with the surface beneath ?

If not you may be able to grip it with a pair of mole grips and wind it out.

If its flush then as rick suggests you will most likely need a stud extractor.
 
Sadly it has sheared off flush so there is no hope of getting any grips on it. Hadn't thought of trying suprrglue, guess its worth a try.
 
Sindri said:
Sadly it has sheared off flush so there is no hope of getting any grips on it. Hadn't thought of trying suprrglue, guess its worth a try.
Click to expand...

I would honesty pick up a set of extractors they are cheap and 8 times out of 10 they work. If you mess up with superglue you will just lock the thread in more and make life harder IMO.
Also if enough torque was applied to shear the bolt in the first place, my guess would be that superglue just wont withstand the forces. :confused:
 
If you snap off a screw extractor (Easy-out) trying to remove the damaged bolt you will never be able to remove it!

They are made of hardened steel and cannot be drilled by normal means!

If it snapped off flush it is likely that it had already seized (Due to corrosion, nobody's fault unless you blame the manufacturer for poor design!) and snapped off when it was last Unscrewed! rather than when it was last done up (By over-tightening)

The best way of dealing with this is to get somebody who knows what they are doing to carefully drill it out and fit a helicoil.

(This is a simple looking task but does take considerable skill so dont try it yourself unless you are willing to run the risk of rendering it totally FUBAR! :D )
 
Get a nut that is slightly larger than the original thread diameter of the old sheared bolt, drop the nut over what's left and weld the nut into position.
Allow to cool, undo nut..... gently
 
Fuzz's option above is by far and away the best and is what a garage will do for a couple of quid.

If you really want to do it yourself You could try a reverse thread drill bit, normally there is next to no tension left in the bolt and it comes straight out. A normal drill bit will potentially shift it too if you reverse it back out, or if there is anything left exposed at all cut a slot into it with a dremel and tap it out.

Honestly though the first option is the best
 
What about using a small cold chisel to make a notch then gently trying to unscrew it by tapping it in an anti-clockwise direction?
 
There isn't really access to cut a ridge into the remaining bit of bolt. Sadly i dont have any welding gear so i will have to try and get a garage to sort it.
 
I'd be tempted to try an easy out but would be bricking it doing it myself! How big is the bolt and how easy is access? Pics please :p
 
coil pack is probably going to be a 10mm headed 5/6mm thread.

Not a chance in hell you'd get..
1. a drill bit down the centre of that steel bolt in what is probably an aluminium housing without drilling off into the aluminium.
2. An easy out big enough to put enough force on it to "un-seize" it.

Forget it and get the welder out.
Trust me, it works, the combination of heat and good strong weld does the trick.
Even if the first couple of nuts break off, keep welding new ones on and "tease" it out, she'll come. :)
 
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