Broken Bolt - Need Advice

[AndrewBird]

Yeah, that is fucked. It's going to need a machine shop. Only way to get that back on track is plunge with an endmill until the top of the bolt is flat again, then drill it out.

For future reference, ALWAYS ALWAYS ALWAYS center punch the bolt before drilling and use a small drill, at least half the bolt diameter, until you have a hole through the middle. Then step up in size slowly until you reach the tap drill diameter (3 steps is generally enough unless it is a very large bolt) or until the drilled hole reaches the edge of the bolt (if the hole isn't on center for example).

If the bolt broke while trying to remove it, use heat to help break it free. If it broke while tightening, it should be loose in the hole as the head of the bolt is what puts tension on the bolt. No head, no tension. In this case, a lot of times you can turn the stud out with a pick, or drill and use an easy-out.

[Andre3127]

Regardless of how, if the new bolt hole is not 100% concentric with the old hole, the seal will be offset and will a) leak and b) wear out prematurely.

This bolt hole doesn't locate anything, it just holds the seal in place. The seal housing has its own register to align it into the head.

OP: what cylinder head is this? I have a 200 eta head I can pop in the mail for you for cheap.


Sent from my XT1053 using Tapatalk

[BimrFett]

OK, so I went on a vacation (cruise) and tried my hardest to not think about the car. That didn't work out well....

I greatly appreciate everyone's advice.

I'm sleeping on:
- pull the head / take it to a machine shop
- pull the head / replace with new head.

Sent from my SM-G930R4 using Tapatalk

[varg]

The hardest part of pulling the head is getting the rusty exhaust manifolds off. It's not too bad other than that imo.

[Mpolito3355]

Kinda looks like your best bet is to overdrill and retap the hole in M8. Theres no reason that wont work. If your not confident maybe get a machine shop to do it, they will come out to you usually if you ask them nicely :)

I'd say itl leak if you only use one bolt..

Why not try this before you pull the head , worst case doesnt work and your back to pulling the head but atleast you tried .....or it could work and your good

Good luck !!!

[citizen_insane]

In the future, another option for removing a broken off steel bolt in an aluminum hole is to use alum, water, & heat to dissolve the steel. You can look up the details online, but basically the alum will dissolve the ferrous metal without damaging the aluminum.