Stuck/broken bolt advice

[calvin1]

I'm working on a Mini Cooper S to replace the cylinder cover. I managed to get the whole thing off without breaking any of the plastic pieces BUT I did break a bolt off in the head. You can see it here just to the right of the spark plug well.

Here's the one that DIDN'T break for reference.

Is there any way to get what's left out myself in my driveway? I'm really tempted to RTV the thing back together and never think about it again.

 

[Oro_O]

Is there any way to get what's left out myself in my driveway? I'm really tempted to RTV the thing back together and never think about it again.

That would be a very bad idea for a number of reasons.

Drill it and extract it. You can google this.

Also, if you are going to attempt things like this, learn the techniques to remove frozen bolts - heat, impact, etc. Again, in this day and age, google is your friend and it's really easy to learn. You need to replace it with a proper head bolt and not just something from the tool box or Ace Hardware.

 

[Kestas]

This doesn't look like a head bolt.

 

[calvin1]

That would be a very bad idea for a number of reasons.

Drill it and extract it. You can google this.

Also, if you are going to attempt things like this, learn the techniques to remove frozen bolts - heat, impact, etc. Again, in this day and age, google is your friend and it's really easy to learn. You need to replace it with a proper head bolt and not just something from the tool box or Ace Hardware.

• It's not a head bolt.
• It only needs to be sealed enough to hold intake vacuum
• Out of all the different ways stuck bolts can be removed, looking for advice on how THIS situation is best handled.

 

[The Critic]

In my sheltered CA life, those bolts tend to be free of corrosion and rust. They usually do not break unless someone has overtightened them. In my situation, I would probably center punch and attempt drilling it out with a left-hand bit.

Your experience may vary.

 

[Oro_O]

• Out of all the different ways stuck bolts can be removed, looking for advice on how THIS situation is best handled.

Drill it and extract it; mentioned clearly. Twice now.

 

[mattd]

You could try to drill it and use a multispline extractor or otherwise drill the whole way

 

[Astro14]

That won’t be a particularly hard bolt (metallurgy) because it’s low stress. It’ll be easy to drill. Hit it with a center punch to establish center. Start with a very small drill. Like 1/8”. Cobalt/sharp bit. Mark the depth you want with tape or a collar. Then go up a size, like 1/16”. Then go up one more size until you’re close to the size of the bolt (a 5mm, I would guess, so max drill bit size would be about 5/32” for the shank of the bolt.).

Then, it should be loose enough for an easy out to work. Heat up the aluminum and use the easy out.

Be prepared to retap the threads. Maybe even helicoil them if the drill bit dug out too much.

 

[JHZR2]

Ugh that stinks. Do you have some ez-out bits that are reverse engaging? Seems like you may have a few options but that would be the right first step.

I’d have to wonder if you could hammer a flat screwdriver in and back it out (with heat, oil, etc.).

Worse comes to worst, drill it out and use a time-sert or equivalent. I don’t think you want to do without a bolt there because your seal into the spark plug riser will be more prone to leak.

 

[calvin1]

In my sheltered CA life, those bolts tend to be free of corrosion and rust. They usually do not break unless someone has overtightened them. In my situation, I would probably center punch and attempt drilling it out with a left-hand bit.

Your experience may vary.

You don't know what you're missing! Spray seawater over your undercarriage every day from December to March for 10 years to get a similar effect. I owned 2 broncos and an OBS F250 and never worked on any of them without needing the BFH and some propane but this fiddly stuff is new ground.


Set of left-hand bits should arrive Monday.

 

[atikovi]

I'm really tempted to RTV the thing back together and never think about it again.

How many bolts total are there? If you have at least 3 or 4 more, your idea would probably work fine. It's just splash lubrication that the cover contains.

 

[calvin1]

How many bolts total are there? If you have at least 3 or 4 more, your idea would probably work fine. It's just splash lubrication that the cover contains.

This is the whole part. There are 10 bolts around the perimeter and the 2 inline with the spark plug wells.

 

[JeffKeryk]

I am guessing there is no torque on that bolt. Try spinning it out. I have even uses a pencil magnet to spin out broken bolts.
Now if there is corosion, that's a different story.

Good luck.

 

[atikovi]

I wouldn't worry about one missing bolt. RTV around the hole and call it a day.

 

[Dave9]

• It's not a head bolt.
• It only needs to be sealed enough to hold intake vacuum
• Out of all the different ways stuck bolts can be removed, looking for advice on how THIS situation is best handled.

Heat, cool, penetrating fluid, grind flat if not flat enough, center punch, left hand drill about 1/2 the diameter at most (smaller is better), working slowly to keep drill centered. If it doesn't pull out, next size larger left hand drill and so on. If getting near the hole diameter, I'd switch to an extractor while reheating it again.

If you can't get it out, consider RTV a last resort rather than 1st resort.

 

[atikovi]

I am guessing there is no torque on that bolt. Try spinning it out. I have even uses a pencil magnet to spin out broken bolts.

That may work on bolts broken from over tightening, but this broke when he tried to remove it. It must have seized in the hole so those things won't work.

 

[mrtrueblue]

This may sound a little extreme but I have seen guys remove things with det-cord. That cylinder head sure wouldn't be an issue anymore.

I'm not sure it's the best idea in this case, the rest of the car is worth keeping, but since nobody else mentioned it....

 

[repairman54]

I use left handed twist drill bits for drilling a bolt for bolt extraction. Sometimes after getting into the ''meat'' of the bolt is will back out as it's center comes out.

 

[MasterSolenoid]

In my sheltered CA life, those bolts tend to be free of corrosion and rust. They usually do not break unless someone has overtightened them. In my situation, I would probably center punch and attempt drilling it out with a left-hand bit.

Your experience may vary.

And if the 'left handed' drill does not remove it (but it may), then try an Easy-Out.

 

[calvin1]

And it's all back together. The left hand bits didn't do anything a regular one wouldn't have since I had to drill out 95% of the bolt. I was able to salvage enough with a tap that I didn't need to do a helicoil. The threads are a little rough but they're holding fine. Thanks for all the suggestions.