Thread: Broken Bolt in Cylinder Head. Ouch!

Removing an overtension-snapped bolt tends to be not too hard, unlike rusted in snap-offs. Centre punch the remnant, drill with a 4mm drill bit, insert a suitably sized easy-out and turn carefully. Some people recommend left handed drill bits, they can unscrew a broken stud without any extra tooling. Any tool shop should stock screw extractors, buy only good quality ones or you may snap it off and treble your trouble.

I dont think I could take treble the trouble.. struggling as it is.

Centre punch I hav and I'll buy a good and fresh 4mm drill bit


'easy-out'

Theres some real cheap sets on ebay. Would like to get a good set.

Fanciest I found was this:
http://www.ebay.com.au/itm/SCREW-EXT...item3cc67f7733

Any brand reccomendations?

The stuck bolt is LR part number ETC7530, which microcat says is M8.

28Nm....

does the WM indicate this or I think it may be a quite a low torque figure + "x" degrees ? ...better check

anyhow... I'm sure you are not the first to do it so don't worry too much - there is more than one remedy if it doesn't come out easily.

including drilling with a larger drill (remaining under thread size) and easing the shell of the bolt out and then, if you do damage the thread, there are always helicoil type repairs available

If you're not confident to do any of these a head reconditioning workshop would do it.

checked the torque page on WM and it suggests 5Nm + 50 degrees

Blasted video!
[ame="http://www.youtube.com/watch?v=CM4kElPjyus"]07 fitting rockers back - 04 broken timing belt - Land Rover 200tdi Engine - YouTube[/ame]
See 4:14 - Says 28 - 32 NM

My torque wrench doesnt go as low at 5NM so may have to get one of those mini cyclist ones or just do it up till it feels/looks right.

This torque table indicates 28Nm is correct for an 8.8 grade M8 x 1.25 bolt:

http://www.google.com.au/url'sa=t&rct=j&q=m8%20torque%20figure&source=web&c d=1&ved=0CFkQFjAA&url=http%3A%2F%2Fwww.npfasteners .com%2Fpdfs%2Fmax-rec-tightening-torque.pdf&ei=_Ti6T7rfKcuUiQe1uIzjCA&usg=AFQjCNFmJ I8yBX1KXQMXLWRfFqflW-a8qg&cad=rja

Sometimes little more than a small sharp screwdriver tapped into the hole will get a broken stud end out. I don't know about that set of screw extractors, perhaps try something like these with a known manufacturer:

ABW by Sidchrome Screw Extractor Set BRAND NEW | eBay

Of course if your bolts were angle torque they should probably all have been replaced!

DON'T BUY CHEAP EASY OUTS, CAUSE WHEN THEY BREAK THEY ARE VERY HARD TO DRILL OUT.

Originally Posted by bee utey

This torque table indicates 28Nm is correct for an 8.8 grade M8 x 1.25 bolt:

http://www.google.com.au/url'sa=t&rct=j&q=m8%20torque%20figure&source=web&c d=1&ved=0CFkQFjAA&url=http%3A%2F%2Fwww.npfasteners .com%2Fpdfs%2Fmax-rec-tightening-torque.pdf&ei=_Ti6T7rfKcuUiQe1uIzjCA&usg=AFQjCNFmJ I8yBX1KXQMXLWRfFqflW-a8qg&cad=rja

Sometimes little more than a small sharp screwdriver tapped into the hole will get a broken stud end out. I don't know about that set of screw extractors, perhaps try something like these with a known manufacturer:

ABW by Sidchrome Screw Extractor Set BRAND NEW | eBay

Of course if your bolts were angle torque they should probably all have been replaced!

The sidchrome one appears to be a punch in type whereby you drill a pilot hole and hammer the extractor in as opposed to screwing one in. My bolt is 2cm down a recess, not sure if that makes a difference... but which type screw in or punch in works best?

Did the same with a couple of exhaust manifold bolts. If you are not confident, best not to risk it. We have a person who calls himself the "Bolt Man", does house calls for just that problem, I'm sure if you let google be your friend, you would find a similar service in your area. Worth a try for peace of mind, Bob

[ broken ezy-outs are expensive to get removed ]