How to remove broken bolt....

[ontoy]

I was changing my front valve cover gasket and when i put everything back together and torque the bolts to 12ft/lbs as mention on one of the thread over here, the bolt snap in half. So what type of bolt extractor should i use to take the bolt out.





I did manage to remove the front one by using a vise grip and just screw it all the way out. But the one on your right hand side when facing the car is block by the head engine block.

[Nervous]

You are lucky, there is a space for a drill. Just drill it out, with something like this
I have a related question. Does anybody know the OE part number for valve cover bolts? To avoid this kind of headache I would buy a set of these bolts.

[ontoy]

I have tried a couple of bolt extractor from lowes, napa, the one that you can buy alone and not the set and 5/16 drill bit. But it was real hard to drill on the center of the bolt due to fact that it is flush all the way inside. I can't really see if i'm drilling the center, i don't want to ruin the threaded part inside. Don't want to remove the whole valve cover again and try drilling from there. Anybody out there that have encounter this problem, please let me know exactly what bolt extractor you have use to remove the bolt safely.

Oh and the OEM part # for the bolt is 90080-10288 $2.40 each.

[JohnGD]

I don't think these cover bolts are meant for anything over 6 lb/ft. And that's for steel bolts. These are aluminum?

Maybe drill a smaller hole to preserve the cylinder head thread. Then use the 5/64" or 1/8" screw-out to extract it??

http://www.harborfreight.com/cpi/cta...emnumber=40349

Also, when you drill, see if you can use a metal sleeve (tube) to help center the drill. So you put a suitable sleeve inside the bolt hole and a slightly smaller drill bit in it so it won't walk. I'm not sure if a stack of small nuts will work or not.

[Nervous]

Originally Posted by ontoy

Oh and the OEM part # for the bolt is 90080-10288 $2.40 each.

Thanks! BTW, at http://www.partznet.com these bolts are $1.24 each.

[ontoy]

JohnGD,
I have use a similar bolt extractor from lowes with no luck, the hard part is drilling the center of the broken bolt and damaging the inside threaded area.

[JohnGD]

Yes, have to use a centering tool. A sleeve/tube (or sleeves/tubes) or stack of nuts.

But it may be faster/cheaper to call a local engine shop and ask for quote. They frequently have to deal with these.

Originally Posted by ontoy

JohnGD,
I have use a similar bolt extractor from lowes with no luck, the hard part is drilling the center of the broken bolt and damaging the inside threaded area.

[ontoy]

Hey, thanks guys for the quick response, yeah i might have to call a local engine shop and see wassup. The good thing is that no oil is leaking, i might just leave it as it is and try to remove it when the next gasket replacement at another 100,000 miles or whenever it starts to leak. I did get a tip from one of the member here, forgot his user name, but he uses 2 washer along with the OEM bolt, that way the end of the bolt won't sink all the way in and causing it to snap when overtighten. I did follow this method when i put in the new bolt and it works, torque it to 5-6 ft/lbs. But i left the other bolts just how it is, don't want to break anymore of these bolts.

[hill8570]

Use a center-punch to make a starter hole and then a run a reverse drill bit down into there. Since it probably isn't frozen in place, you should be able to go in with a bit quite a bit smaller than the bolt diameter and still have it spin out, so you should have a real good chance of not screwing up the threads. Heck, you might even be able to get an easy-out to work, but I generally don't like those, 'cause when you break them off, you're really and truly screwed.

[73sport]

This works well in soft aluminum!

- Remove the valve cover so you have flush access. Cover the important guts!
- Get a dremel tool or die grinder and fit it with a cutoff disc. You need to cut wide enough and deep enough slot through the center of the bolt to fit a small screw driver tip into it.
- Let the disc cut into the head so a screwdriver tip gets into the broken bolt at least a 1/16" or so.
- You will likely cut two small grooves into the head so be sure to Correct your angle to go with the direction of the gasket, not across the sealing surface!
- With that slot, you simply use a screw driver to screw it out.

A couple of magnets in plastic bags can be used to grab some of the spray. The bags make easy magnet cleanup. Just peel it away and the magnets clean!

Note; this doesn't work to well on cross threaded bolts and studs.

Take a look at this fix for the shallow 1mz plastic valve cover shroud. Its the same idea.



You can also try using a very sharp punch and hit the center for drilling purposes. Leave the valve cover on as a guide for your drill bit when drilling. Now place some hobby shop brass tubing over the drill bit and increase the size until you just have contact with hole in the valve cover. This is our guide so you don't go off center!

Snap-on, mac, those guys sell extractors. Worst case if miss the whole during drilling you yank the chunk out and hopefully drill the threads clean and put a helicoil in the hole. This would suck on the back of the 1Mz!

[ajkalian]

You can get these tools from many places. Here's what Harbor Freight has.

Here's how to center the drill bits. They are called Vix Bits and they are most commonly used for centering the holes when installing hinges. But they will work well to center the bit on a snapped off bolt head. If you buy a set of them, there should be one that fits the hole in the valve cover. You can wrap tape around a smaller one to make it fit.

http://www.harborfreightusa.com/usa/...bCategoryName=

Only drill about 1/16" deep just enough to center the drill, *then* remove the Vix Bit, and chuck up a left handed drill bit, put the drill motor in reverse so it turns counter clockwise, and begin to drill a hole in the snapped off bolt. The drill bit will grip in the process of drilling, and it is usually enough to spin out the broken bolt. Use the largest left handed drill bit you can fit in the hole so as to minimize the chance of breakage.

http://www.harborfreightusa.com/usa/...submit=find+it

This process works almost 100% of the time, and is much better than easy-outs which just tend to expand the broken off stud in the hole. Or worse, break off......and then you really have a problem.

Good luck, hope this helps.