Okay, I've made a horrible mistake while attempting to use a torque wrench. Long story short, I broke two of the big black valve cover bolts and need to find replacements, and ideas on how to remove the bits of bolt stuck.

edit: There about 2-3 loops of exposed thread exposed above the broken bolt.

 

Can you drill them and then use an easy out to back them out.

 

Okay, little update. I got some similar bolts, but they are threaded up to the head and don't fit snug in the seals can I still use these? I also got some drill bits that should help remove the broken bolt already there.

 

Okay, here are photos of the two different bolts. The black one is the original. I went to a store that specializes in having a diverse selection of bolts and this was the closest they had.

imgur: the simple image sharer

 

I could be wrong but they don't look the same?

I am sure you are a lot smarter than that.

It would be better to use the bolts that you have and put chewing gum in the spare holes - or buy some OEM bolts??

 

I wouldn't use those new bolts. Get some bolts from dealer or a breaker.

Drilling broken bolts should be absolute last resort. If you have some thread showing I would try these in this order first:

- Mole grips
- Stud extractor tool
- Small cutter socket (like the ones used for locking wheel nuts)
- JB Weld another bolt on to the end of the broken bit

Good luck.

 

2-3 loops of thread are not a lot to go at, but could you get a nut onto the bolt end?

If yes, then in a vice carefully slice it in half. Rescrew the two halves onto your thread.

Using two thin spanners, tighten the top one against the bottom one (careful to hold the bottom nut to prevent it being tightened down even more), and then holding the top nut in position use your second spanner to unscrew the bottom nut against the top nut.

Because it can't unscrew, this will have the effect of unscrewing the whole stud.

But you might not have enough thread showing.

Method works for extracting in various situations.

I would not use the new screws as anything other than a temp patch-up. The unthreaded portion is there for a reason, it goes through a gasket.

 

Bugga,

As already said, DO NOT use those "new" bolts, you will distort the cover, have more oil leaks than you currently have.

Get the CORRECT bolts and a set of camcover seals for ALL those bolts.

Since those bolts you broke are "shanked" the broken thread "should not" be tight in the threaded hole, as they do not bottom out by design.

Try some GOOD quality grips and they should just undo.

If you want to go the nut way, simply find nuts to fit all the broken bits, clean it all up with carby cleaner or similar, thread the nuts on ALL the broken bits, mix up some JB Weld and drop a GOOD drop in the top of the nuts, it will "wick in" and tomorrow morning simply undo them, broken bits and all.

I do not use a torque wrench here, yeh I know, but snapping these small diameter bolts is just too easy, and especially those shanked ones. They will not pull that cover down any further, that is the way it is designed, and the brain wave to try and "give it a bit more" ends up where you are at.

I think you need a DRINK. Have a couple for me, as I will for you.

 

Well, at the moment I'm teetering on the edge of the worst case scenario for getting the broken off bits of bolt out because I have no other choice than to drill it out and may nearly have to re-thread the hole.

Out of my morbid curiosity what makes the new bolt so bad to use? Is it just that I could do something stupid like tighten it too much? How bad would it be to use the new bolts just for a day or two? I'll try calling a dealer tomorrow to get some new bolts. I'm kinda screwed because I haven't got another car.

 

Did you try the epoxy route explained by Grant Francis? It sounds the most reasonable of the options presented. However it requires the full curing time and enough warmth for curing.

Drilling the way you think is the worst of all options.

If you *must* drill, then research using "easy outs". These are reverse threaded taps that you screw into a broken bolt that has been drilled *smaller* than the thread. That is, you only drill the bolt center. This leaves the thread untouched. It is still not a good option because it requires skill and experience to do it just right.

Another option that requires quite a bit of manual dexterity is to use a very small cape chisel to catch the edge of the broken bit tangentially and tap gently counter clockwise to ease the bolt around a few turns until it can be turned out using vise grips. The chisel is *not* being used to remove any metal, it is being used to *turn* the remaining bolt. As a matter of fact, losing metal in this technique is a bad thing because it is needed to engage the chisel tip. Again, this technique requires experience, planning, patience and thought.

Finally, there is the option of paying a garage to remove the bolt.

 

OK, point taken.

If it were mine and you dont have another car, cab, bicycle, bus, whatever to get you where you really neeed to go, then put the cover back with RTV on the gasket AND the spark plug seals and FORGET about the braoken bits. Dob some RTV in the holes of the cover where the broken bolts are missing, and do what you have to do. Get the correct bolts as discussed, and their seals, and do it ALL again when you have time.

I did this same "patch" with one of my old XK engines when dumbo here snapped on of the studs that hold the camcover on, the ones with the pretty chrome dome nuts on top, and they are part of the camshaft retaining bits and pieces. Took 6 months to get to do it proper, and that RTV stopped ALL the leaks so no messs to annoy me. I know a very different engine and all that stuff, but I dont reckon you will have anywhere as many issues with a couple of bolts missing as compared to the possible muck up of those wrong bolts.

I am NOT doubting your ability at all, but sometimes less is better than pretend.

 

Well, the old broken bolts are refusing to come out after several different screw extractor kits. One of the two holes with broken bolts has resigned itself to being drilled out and re-threaded. I know. It's terrible. I don't want to do it, but we've come too far. We still may be able to salvage the second bolt hole. This was supposed to be an easy fix, but I HAD to break some stupid bolts.

 

I have been following your problem. If you have any part of the original bolt still sticking out of the hole or flush with the surface,try putting a slot in the remaing part of the bolt(a dremel with a abrasive disc will work). Then you can use a screwdriver to screw it out.But before trying to take it out heat the area (a towel or rag soaked in hot water will work)and once its warm it will give a little more clearence(aluminum expands more than steel) then screw it out.[I]f successful then use some jb weld to level the area re tap the holes and reassemble.

 

well I read through the whole thread and was getting ready to post till I read Lumpys post. Thats exactly what I would do. I know alittle late, but slotting really works well and for the most part no damage or further work needed. Ive removed many a bolts this way

 

Well it's good that you posted anyways. Your recommendations carry a lot of weight on JF.

 

Well, we ended up having to re thread one hole to the original bolt size 6M, and the other a size larger and use a heli coil. I am using 2 replacement bolts which have sealed up surprisingly well, and have new OEM bolts on the way from Coventry West which will be here tomorrow or the day after.

 

Sweet, another success story.

 

Good news, well done!

 

I broke a cam cover bolt when torquing {used too big a wrench}
looked at eze outs and left hand drills as options to remove.
Finally figured i could do more damage and located a Mobile Welder Operator .
He came to house and welded nut on the 1/16th of bolt . Heat loosened broken bolt and it came right out .
Cost $70.00 {expensive lesson} but cheaper than tow/ machine shop costs.

 

Hey Graham, glad to hear you got that one resolved. $70 for that sort of work AND at your home to boot is a very good deal.