Snapped Headbolt

[tagy 1]

While taking the head off my 1.6, I loosened the first 9 headbolts a quarter of a turn, then the final bolt snapped:

 

 

I was hoping the remains would be sticking out above the block, but no such luck, it is sitting 1cm below the face of the block. Damn.

 

Now I don't fancy trying to drill it out, any ideas?

 

Pretty sure the headgasket has gone!

 

[DamirGTI 344]

s*it i've had just the same issue om my first engine and had to scrap the block , if it's broken down below the block surface it'll be a bitch to drill out ... you'll really struggle to drill it in the center , and if you don't make a hole on the bolt remains in dead center it'll be hard to remove it with stud extractor ..

 

As for me , only option might be removing the engine out from the car , strip the block and take it to the machine shop and let them remove it for you , and if needed , insert an “heli coil” inside the hole afterwards the bolt is removed .. as by trying to drill it out by yourself you can do more damage than good ..

 

Best luck !

Damir

[Alfie 6]

While taking the head off my 1.6, I loosened the first 9 headbolts a quarter of a turn, then the final bolt snapped:

 

 

I was hoping the remains would be sticking out above the block, but no such luck, it is sitting 1cm below the face of the block. Damn.

 

Now I don't fancy trying to drill it out, any ideas?

 

Pretty sure the headgasket has gone!

 

Think drilling it out gonna be your only way out of this tagy, Can you get a drill straight up on the block face, you haven't mentioned which stud has snapped. If you can, I'd make sure that you mask up any possible ways in for swarf. Then center pop remains of stud..accurately as possible! Use a good drill bit, one that has a little clearance in the stud hole, I would then use another drill, a smidgen bigger, now you should have left in the hole the threads of the old stud, Using the correct size tap,gently, turn in the tap,halfturn at a time,backing out out after every half to 3 quarter turn and keep clearing the swarf. carry on slowly down to same depth as other studs and stop. be better if you can use a taper tap first, then down again using a plug tap. Make sure you use new bolts and identify correct size drills and taps using same. Just take it steady, let the tool cut and keep the drill and then the taps up straight. A little oil on them as you drill and cut will assist greatly. Drills and taps and handle are not mega bucks but new head bolts particularly in your engine are a must!. I'm no expert but this how I would tackle this and I hope it helps you.

[2-Pugs 57]

I had this happen when I replaced the head gasket on my car last year, although I was left with less of a broken bit, and further down in the block compared to yours, so there was a good 20-25mm of depth of block above where it had broken. I managed to sort it out by neither scrapping the block nor drilling it out. What I did to get around it was actually leave it where it was. With a lot of help from the toolmaker at work, we made a threaded insert. We tapped the clearance hole in the block above the remaining broken bolt using a blind tap, to M14 I think I was. Then die'd an M14 thread onto the outside of said insert. The insert was then drilled and tapped to M11 (or whatever the head bolt thread is, I forget now). This insert was then wound into the block, which gave us thread almost up to the top surface. Finally, we cut a bit off the bottom of the new head bolt to clear the snapped bit that was still left in there (the replacement head bolts I got had thread almost all the way up, unlike the originals, which was lucky) . Worked an absolute treat. It torqued up fine and it was probably stronger than some of the original threadforms that are still in the block. A year on, it's been no bother, but then I dont drive hard nor do I do many miles. In the case of a hard driven car, or daily runner you might want a better repair method. But my block had quite low milage and I really didn't want to scrap it! This method worked fine for me and I'd recommend it.

 

Not long after, Stee1FM off here had a similiar problem, one of his head bolts snapped. He found a kit containing a series of 'tube' things with ever increasing bore sizes. You put the tube in the hole in the block, which is sized for a close fit, then use it as a drill guide, progressively drill the bolt, working larger and larger drill bits until there is nothing but threads left. The tube thing acts as a drill guide and stops the drill slipping off and into the alloy block.

 

Seemed to work ok as well

Edited February 21, 2009 by 2-Pugs

[2-Pugs 57]

Two other things worth doing (both of which I read on the Puma Racing site, so all credit to him) are;

- make up a 'tap' out of one of your old head bolts by grinding 3 flutes along the thread. Together with some cutting fluid or oil, run them through all the threads on the block before reassembly, just to clear them and make sure they are in good condition.

- use a sh*tload of copper ease or molybdenum grease on the threads of the new bolts to at least try and stop them seizing again. Fill the exposed hole from underneath with copper grease to stop and crud spraying up there from below, that might cause corrosion again

Edited February 21, 2009 by 2-Pugs

[marksorrento205 80]

Two other things worth doing (both of which I read on the Puma Racing site, so all credit to him) are;

- make up a 'tap' out of one of your old head bolts by grinding 3 flutes along the thread. Together with some cutting fluid or oil, run them through all the threads on the block before reassembly, just to clear them and make sure they are in good condition.

- use a sh*tload of copper ease or molybdenum grease on the threads of the new bolts to at least try and stop them seizing again. Fill the exposed hole from underneath with copper grease to stop and crud spraying up there from below, that might cause corrosion again

 

 

Cant agree more. As said centre pop and drill and tap. I have found a left handed drill bit works very well as the bolt has snapped in an anti clockwise direction due to you undoing it, drilling with a normal drill can sometimes be tricky but by no way impossible. Good luck.

[Cameron 16]

Use a screwdriver and a hammer and tap the top of the bolt to loosen the threads, then you can use a small screwdriver to tease it out. Very fiddly but it works.

[stee 1FM 0]

hi mate

as 2-pugs said i used an extractor set, very good but drill as bigger hole as possible.

 

i used the BLUE POINT SCREW EXTRACTOR SET no1020

 

think its on the snap-on web sit.

 

stee1fm

[Tom Fenton 1,548]

A way to help drilling is to hire a magnetic clamp on drill, these are usually used for drilling roof girders in situ, they have a strong magentic base to clamp onto a flat steel surface. I used this method on an Mi16 engine in a 405, made a 4mm thick steel plate to fasten to the top surface of the block, this allows the mag base to clamp onto it. Then you can drill the stud out and get it perfectly square.

Personally from experience I wouldn't bother trying to reclaim the original threads, instead get hold of a helicoil kit (11x1.0 thread size) and then helicoil the hole. I found putting two short inserts in one above the other worked well.

[tagy 1]

cheers for suggestions, been out having a go, but as the car is outside my flat I only have a battery drill and as I expected it is not up to the job. Tried tapping the remains round with a screwdriver and hammer but its not moving.

 

Thinking it might be easier to fit another working engine, but the shell is not mint (rust), otherwise I certainly would do so. Another option is break it for spare parts selling some, and keeping some spares for my track car.

[jeremy 71]

I had this happen to me when doing the reverse ie putting the head back on, completely my fault. In the end I took the block out and managed with a ring spanner to slowly turn the bolt so that it came out the bottom, along with drilling some small holes through the bolt and using a fine screwdriver to turn it. The one I sheared was centre back, and took my six hours to get out.

 

All the best

 

Jeremy

[Cameron 16]

I suggested this to a bloke on FSC and I think it stands a very good chance of saving your bacon.

 

First, give it a good squirt of Plusgas / WD40 (from top & bottom) and let it soak for a bit. I reckon if you drill, say, a 5-6mm hole down the centre (centrepunch it first) and then beat a long reach torx bit into it you'll have plenty of grunt to loosen it. When you wallop the bit into the hole that should also help shock the threads loose.

 

Give it a try, hopefully it works and you'll avoid having to fork out for expensive repairs.

Edited February 24, 2009 by Cameron

[Duroc 2 1 Cars]

Personally from experience I wouldn't bother trying to reclaim the original threads, instead get hold of a helicoil kit (11x1.0 thread size) and then helicoil the hole. I found putting two short inserts in one above the other worked well.

 

M11x1.5

[woodsy 0]

i had this happen to 2 gtis.I tried everything to get the snapped rear bolt out.Ended up giving my car to a mate who runs an engine recon

shop and is a great engineer.He ended up fitting a insert on top of the snapped bolt and used a head bolt of a diesel as they are shorter, thus sitting on

top of the broken bolt.It wasnt a helicoil or anything it was proper made sleeve.

[tagy 1]

I suggested this to a bloke on FSC and I think it stands a very good chance of saving your bacon.

 

First, give it a good squirt of Plusgas / WD40 (from top & bottom) and let it soak for a bit. I reckon if you drill, say, a 5-6mm hole down the centre (centrepunch it first) and then beat a long reach torx bit into it you'll have plenty of grunt to loosen it. When you wallop the bit into the hole that should also help shock the threads loose.

 

Give it a try, hopefully it works and you'll avoid having to fork out for expensive repairs.

 

interesting idea will give it a go, not giving up yet!

[kilauea 7]

I had no idea this was so common. I'm about to remove my first head and I'm bricking it now!

Any advice on avoiding this happening? I am in no rush.

[Guest 99hjhm]

How common is this problem?

[Cameron 16]

Not that common really, I certainly wouldn't be scared of taking your head off! Its just one of those things that happen just enough to look like it happens all the time. If that makes sense.

If you want to minimise the chances, spray some Plusgas on the exposed threads, then crack each one off in order. You only need to loosen them a tiny bit, say 45 - 90 degrees. Once they're all loosened you can pretty much continue as normal. Its just the first bit where they suddenly creak that risks snapping them (and tools).

[Alfie 6]

Not that common really, I certainly wouldn't be scared of taking your head off! Its just one of those things that happen just enough to look like it happens all the time. If that makes sense.

If you want to minimise the chances, spray some Plusgas on the exposed threads, then crack each one off in order. You only need to loosen them a tiny bit, say 45 - 90 degrees. Once they're all loosened you can pretty much continue as normal. Its just the first bit where they suddenly creak that risks snapping them (and tools).

There is a school of thought that by first giving them a whack with a tapping stick (hammer) then try to tighten a

fraction, before undoing a stubborn nut/bolt, that this jarrs everything, making it all a little easier to move.

[DamirGTI 344]

.. i would say not more than 1/4 of turn at a time when you undo them i prefer to start undoing them by 1/8 or even 1/16 of turn (just a tiny bit at a time on each bolt starting from the bolt No.10 to the No.1 ..) and do as many stages as needed to fully loosen off the pressure ..

 

But also , i've found that if they're really badly sized (+ if they where reused some time i the past ..) they're just bound to break no matter which procedure you try while undoing them - heating , hammering , liquid treating etc. ... remember these ones are old engines so be prepared to expect the unexpected

 

I'll try to dig a pic of my first engine , the bolt snapped just like a twig as soon as i started turning it was rusted so badly deep down inside the block as if it was welded to the block threads

 

Just take it slow and easy , like when tightening them , do as much stages as you can until the pressure is fully released from all of the 10 bolts until you'll be able to undo them with your fingers ..

 

Damir

Edited February 24, 2009 by DamirGTI

[kilauea 7]

Cheers. Have been giving them a good spraying of penetrating oil the last couple of days anyway. I'll just take my time and hope for the best!

 

Is plusgas really that much better than general penetrating oil? I'll get some if it is, just trying to keep costs down.

[DamirGTI 344]

 

 

 

(bastard)

 

Damir

[Cameron 16]

DOH!! I imagine 8Vs are slightly more prone to this due to the head bolts being exposed.

[2-Pugs 57]

Just to add a couple of points.

 

I always found Plus Gas a lot better than WD-40, perhaps I am imagining it but somehow it seems to work better, so I'd recommend it.

 

As for removing these head bolts, as others have said, just take your time, and soak well in plus-gas or penetrating oil. One important thing to mention is that it is not neccesarily corrosion per se that causes these bolts to seize and snap, e.g. it is not neccessarily due to them rusting in situ. What can also happen (which is happened on mine) is that the aluminium thread can pick up slightly on the bolt as you are loosening it, which results in a small bit of ally getting forced between the threads, which then 'cold welds' the block to the thread and seizes solid. So just because you've 'cracked' the bolt loose and it is still intact does not mean you are out the woods - far from it - you could still get it seizing part way out. That happened on two of my head bolts. One, we caught just before it seized and managed to work out, but the other one snapped unfortunately. What I would recommend is use a T-bar when you are loosening them, because you can get a better feel for what the bolt is doing vs a ratchet, and as you wind them out, keep going back and forth periodically to keep the thread running free (like when you are tapping a thread with a tap). Once there is a gap between the bolt head and the top surface of the block, keep dumping plus gas, or thin oil in there to work into the threads. Keep working back and forth and be patient. If the bolt starts to go stiff it's a sign that it has picked up and is on it's way to seizing , but you can work through it if you're careful. It took me and a freind of mine 2 hours to remove one bolt that was on the cusp of seizing and snapping, but we kept working it back and forth, each time undoing slightly more (a fraction of a turn) and adding tons of oil. Eventually it came out fine. Look at it this way, even if it takes a couple of hours to undo each bolt, then thats a lot better than trying to sort out a snapped bolt stuck in your block!

[boombang 2]

Never had one snap myself (saying that now I bet one snaps next time!) but have my own technique for removal. Only times I've removed heads at home I've been in no rush at all, so really taken my time.

 

First up I agree a decent penetrating oil sprayed/poured over tops of the bolts to allow to soak in, same on the exposed bottoms.

 

After a decent length of time left standing (last head I left for a week and all oil had worked its way through, probably put it on three times over the week) I get the blowtorch out and heat the bolts up a decent amount. Always a fan of heat where there is a possibility of seizure, especially with two different metals where you can take advantage of different expansion rates.

 

Next step (once they cooled off) crack the bolts off in turn - literally just that too, do not attempt to turn them any amount but just to break the initial seal that the corrosion would have formed.

 

If the head is turning over 90 degrees without cracking off, go again with the heat, cool off, then again go for the turn.