Help! Sheared valve cover bolt by firewall

[Bambusiero]

Doesn't seem like it will be in tight, so I'm thinking that Kevin's punch method will work, and be the easiest.

However, if it doesn't, I second the suggestion for using reverse (Left Hand) twist drill bits. I found out about that method here on the forum, and it worked for me with a very difficult corroded and sheared off bolt. Once the bit grabs, it may just unscrew the bolt for you. Did for me. For cramped space you need what are called "Machine Screw Length LH" bits. (and probably a right angle drill. I rented a big 1/2" one at Home Depot) I doubt that you would need cobalt bits, just HSS. Also, very unlikely that you can buy the short LH bits locally. mscdirect.com has them and is easy to deal with. Centering the bit in the bolt is important. I used a Dremel with a pea sized round abrasive bit to dish the center of the bolt, to center the drill bit.

Go slow and carefull. Good luck.

 

[MDarius]

Thanks. Someone suggested creaming the bolt with grease to catch any shavings, and using lots of penetrating oil.

What do you think heating the head in that area just a little with a plumbers propane torch to expand the aluminum? If I don't make it real hot...just use the end of the flame, not the brasing point...the aluminum would expand faster than the steel bolt. Should make it easier. Would this cause damage to the head? I'm guessing it's risky, which is why I'm asking before just jumpin' in there.

I'm not going to work on it 'till Monday either way, this being Father's day and all.

By the way, happy Father's day to everyone, even if you're only a Father in spirit!

 

[semlin]

i would not heat it. i very much doubt you need it and you could damage the head.

 

[Driver]

Most of the time when the bolt breaks it relieves the tension on the threads, so it's just in finger tight.

The problem with this is that Lucy was tightening the bolt and not loosening it. Overtightening, at 75-ft-lbs. Since the bolt snapped (before a click) it may not be at 75 ft-lbs, but somewhat less. Regardless, It's still going to take a good amount of torque to get it off. I'm with the EZ-Out group on this. But I do have a few tips. 1) Try to get a center-tap and get the drill positioned in the center. 2) Buy the smallest EZ-Out as possible. If you can get the specs for shearing of the EZ-Out then get the smallest one that will get the job done, i.e., the smallest one with breaking strength greater then 75 ft-lbs. note: you don't want to snap off an EZ-Out. 3) Start with a very small drill bit. Think of it as a pilot hole. You can test the that it is verticle with respect to everything else (ground, lift, head) If it's verticle, you can step up in bit diameter. If it's not you can adjust it with the next drilling. Continue this process, verifying that the hole you're creating is verticle until you can insert the EZ-Out 1/2" or so. 4) Gently tap in the EZ-Out with a small hammer. 5) Use vise grips or locking pliers and turn EZ-Out CCW to remove bolt. 6) It's important that you get the pilot hole straight in or you might ruin the threading. If you destroy the threading, you can either tap a new threading or insert a threaded sleeve. If you really want to ensure a straight pilot hole, you could pull the head and use a drill press. While the head is off you can replace the HG. Good luck.

 

[MDarius]

Thanks everybody for your help. I worked on it tonight and got the sheared bolts out. A little tapping with an awl, a little bloody knuckles, a little vice grips, a little hack saw across the top to turn it in to a straight slot screw, some grease to catch the shavings, and voila! It came right out!

So, now I'm in the put it all back together process. I installed a set of new Bosch Platinum plugs gapped at .031, and I should be able to get back at it on Wednesday and finish it up.

Thanks again for all your help.

-Matt-

 

[Tools R Us]

The problem with this is that Lucy was tightening the bolt and not loosening it. Overtightening, at 75-ft-lbs. Since the bolt snapped (before a click) it may not be at 75 ft-lbs, but somewhat less. Regardless, It's still going to take a good amount of torque to get it off...

Bolts store their energy between the head and threads, stretching the shank. No matter how much torque was applied, when the head is broken off there is no more torque on the threaded part. If the threads are not pulled or buggered it will easily turn out. All bets are off for rusty, corroded, Loc-Tited or cross threaded bolts.

 

[Rainy Day FZJ]

I read the propane torch and thought the next thing you would do is heat it up till it burns!, try using a dental pick and see if the bolt rotates by hand. Good luck.

 

[MDarius]

I asked my bro-in-law / mechanic about heating it up. He explained (duh!) that the aluminum disipates heat much faster than the steel. The bolt would retain the heat better than the head. Aside from risking damage to surrounding items and damaging the head, this was just a bad idea. But it was an idea! Warped logic, but logic nonetheless.

 

[Kasprzak]

BOY DO YOU KNOW HOW TO MAKE A GUY FEEL SORRY FOR NOT SHOWING UP TO HELP. THIS I GET FOR NOT SHOWING UP ON SATURDAY......... Sorry about that Matt, I had a trip to Logan to take home the little girl we are trying to adopt. We had an all day trip to Lagoon. I have a surgical procedure today, I will give you a call a little later today after the Morphine wears off. Closest Smiley I could get that looks high!!!!

 

[fzj80kidpen]

Lucy,
I am glad you have prevailed over the sheared bolt.
Now, what was it you were doing with the valve cover off to begin with?

 

[Rookie2]

Someone suggested creaming the bolt with grease to catch any shavings, and using lots of penetrating oil.

Seems like somewhere in the memory banks, I'm recalling that penetrating oil such as PB Blaster can be corrosive if left in contact with aluminum. Anybody heared of that?

 

[MDarius]

BOY DO YOU KNOW HOW TO MAKE A GUY FEEL SORRY FOR NOT SHOWING UP TO HELP. THIS I GET FOR NOT SHOWING UP ON SATURDAY......... Sorry about that Matt, I had a trip to Logan to take home the little girl we are trying to adopt. We had an all day trip to Lagoon. I have a surgical procedure today, I will give you a call a little later today after the Morphine wears off. Closest Smiley I could get that looks high!!!!

That's alright, My uncle from Antarctica was in town and we went and hung out at the ice sheet for a couple hours. Today I'm going to remove my own appendix...hope I don't shear anything there!

Nah, it's all good! We all have a life and it sounds like yours is a little crazy right now. But...if you have a good torque wrench I could borrow, as opposed to my $20 piece of junk, I would appreciate that.

 

[MDarius]

Lucy,
I am glad you have prevailed over the sheared bolt.
Now, what was it you were doing with the valve cover off to begin with?

I was swimming over my head! It's a long story, but it's like this...'As long as I'm close, I might as well...' Repeat 3 times, rinse, and spit.

Bad PHH > Frustration > removal of the intake plenum to get to the PHH from above (I have code PO401, 'Might as well...') > Valve cover (leaking a little, 'Might as well'...)

Somebody way funnier than me suggested earlier in this thread that since I was almost there, I 'might as well' replace the HG! I sheared off 3 bolts replacing a VC gasket and he wants me to jump in to the HG!! Milk before meat my friends....

Maybe with more time on the board, and under the hood, I'll be replacing my own HG next year.

 

[MDarius]

Seems like somewhere in the memory banks, I'm recalling that penetrating oil such as PB Blaster can be corrosive if left in contact with aluminum. Anybody heared of that?

I didn't have to get to that, although I had it on standy. It would be good to know the answer though, if anyone knows.