OK, its a MINI not my Dodge but you guys are the best technical help and advice I find on any forum...I need mechanical help, and I hope I don't get booted off the forum.

which direction do I drill in an extractor bit?
Will a helix coil work in the aluminum cylinder case?

Had my share of mistakes, problems, and maybe some bad luck, but I haven't ever gotten down to the helix coil thing and it makes me nervous.

Its an aluminum cylinder head, I was tightening the valve cover bolts. Valve cover is plastic, many people have broken the valve cover overtightening the bolts or overtightening the bolts on the coil pack which is on the cover.
I was using a torque wrench so as not to overtighten, but it was feeling too tight so I wasn't tightening down to the torque specs

on the LAST bolt, it snapped before it even felt as snug as the others. I had put antiseize on.

Couldn't drill the bolt out (they are pretty small, use an 8mm socket)
thanks for any help

 

Well, an extractor bit turns to the left, but they're pretty messy... they will score the heck out of the sides of your fastener area.

This is a valve cover or a vanity cover? I have not seen a plastic valve cover before.

 

Yea, I figured I would make a mess because the bolt is so much stronger than the aluminum threads. the way the bolt snapped was crooked, so it was hard to drill out on center. slipping into the threads. So I figure if its a mess already, maybe just try to the extractor and plan on using the helicoil? helix coil?

Its on my MINI Cooper. little car, plastic valve cover, aluminum case.
like I said, you guys have the best technical/mechanical advice on any forum I've ever been on.
The MINI forum folks aren't always as savvy.

 

Helicoil will be fine, we use it a lot on our generator base covers. Just use the drill bit they recommend and drill the hole straight.

 

I would take the valve cover back off if you can and see how much of the bolt is sticking out, if its not enough to grip with a visegrip, I would weld a nut to it.


Madhat, I believe even semi trucks use a plastic/composite valve cover. As they sound like plastic and they flex when you walk on them

 

Barngal - the one time (thank goodness only one time) this happened to me, it was a head bolt on a Chrysler 2.2L 4 banger. I pulled the head off, used a Dremel tool and a grinder to flatten the top of the bolt. Then used a punch to put a small dimple in the middle of what was left of the bolt/stud. Started out with my smallest drill and slowly and carefully drilled out the center of the bolt. When I say slow I mean very slowly and carefully. Gradually increased bit size until I could get an EZ-Out in there. Luckily, with no tenstion on the head bolt, the EZ-Out worked very well. Honestly it was almost a full day job but it worked and not head damage ensued.

 

For sure I would remove the valve cover again and like has been said, just maybe there is enough of the bolt sticking out to grip with a GOOD set of vise grips.

If there is enough material, welding a nut on works too.

There are a couple of other tricks to use in centering the drill to start it. Use a very small diameter drill, like 1/16". It that is too flexible and wonders, then go to a 3/32", but no bigger. If it is possible, make a drill guide and clamp it on, centered over the broken bolt. Another way to make a drill guide is to get a chuck of metal, even an old nut and fill the center with weld. Drill your guide hole in it, like 3/32" and then using some quick setting epoxy, bond this over the broken bolt, but of course centered. Remember to remove the oil from the head first so that the epoxy can stick.

Once the epoxy has set, drill the pilot hole, remove the epoxied on nut, , the rest of the epoxy and in stages, open the hole to the size you need. Be careful going up in stages as the drill can ****** or bind, suddenly pulling it sideways and causing damage. When this happens the drill can break and then you will be in deep doo-doo. Now use the Easyout and you should be in business. Suggest you use all new bolts as you do not know if any others have been strained and are ready to break.

If you are lucky, the threads will be good and you will not need to install a Heli-Coil. However, if you do need to install one, it is no big deal. The drill size they recommend is critical.

Let us know how it works for you.

 

thanks for the suggestions. the bolt is definitely below the level of the cylinder head. I did start with a fine drill bit, but wish I had known the directions for making a jig to keep the drill bit centered. I think I may already have messed up the threads. I may still try the jig, just to see, doesn't sound that time consuming.

another question:

--if I have to install a helicoil, the one I bought is not as long as the bolt.
can I cut the bolt to fit the length of the helicoil, since they are strong?
or should i wait till i find the proper length helicoil?

thanks you guys for the help, I just keep learning. Now when I make a mistake instead of hating myself I just figure--hey, another skill (that I hope I won't need again in the future, but if...)

 

A few threads messed up is probably not going to matter in the long run. You can do a trial installation by measuring the thickness of the cover and then installing some washers or a larger ID nut over the bolt to match the thickness of the cover and torque the bolt down. If it does not strip you are probably good to go. If it does strip, big deal. Now just install the heli-coil.

The heli-coils are very strong, so if it is a few threads shorter than the bolt, do not worry about it. I said a few threads, not like 50%. Installing a shorter bolt will do nothing for you.

BTW, is this a REAL Mini, like the old 850, or the 1100? Mr. Bean's car. Or is it the new version?

 

When my aluminum headed Kawasaki stripped out, I used this http://www.timesert.com/
Insanely strong, not cheap, but it works.

 

Good advice above. As mentioned, centering the hole is the most critical part. If available, I always drill the initial hole with a left hand drill bit. Once in a while you will be pleasantly surprised by a bolt that spins itself right out like that.

Helicoils are pretty simple, just follow the instructions and use care. After installation, they may direct you to insert a small punch and break off the drive tang from the bottom of the coil, after which you are free to use your longer bolt, just make sure you remove the tang piece from the hole with a magnet or blowgun.
Good luck.

 

Forgot about that. If you use a blowgun, DO NOT forget to wear safety glasses because that little tang can come out like a bullet.

 

Very good point. Also, cover up the valvetrain well with rags to keep it from landing inside the engine, since your valve cover is removed.

 

No,its not one of the really cool old ones...they are cool but insanely dangerous if you get hit. (of course, like a motorcycle, you use your speed and agility to get out of trouble)

I have a 2002 with the supercharger, the newer ones are turbocharged. I've done a few mods on it and it is a kick to drive; can't beat the cornering. But it also has 6 airbags and for its size it has a lot of safety features.

I drive a truck, ride a horse and fly the coop....

 

Great advice here as always. If I can't get to it tomorrow night it will be next week (would have liked to drive the MINI to the coast this weekend but if I don't find a longer helicoil its not going to happen)

The time-sert thread system looks like more of a no brainer, so if its gonna be next week I might order one.

I'll come back and tell you how it went. Thanks, I feel confident I can do this now.