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Discussion Starter #1
Hey folks,

I'm new here. I've been doing a top-end rebuild on my 2003 325i--valve job, seals, head gasket, and the other goodies while I'm in there. Things were going great today as I started the timing procedure. Had to go back a couple of steps when I realized I forgot to insert two of the cylinder-head-to-timing-cover E8 external torx bolts. I ended up getting the wrong torque specs, overtorqued the 70mm bolt (driver side), and it snapped deep down in the timing cover.

Unfortunately, everything I have tried so far has not worked (picking and attempting to access with drill bits), and the go-to options don't really work here given how deep the snapped bolt is in the timing cover. Can't seem to even find any left-hand thread drill bits appropriately sized and capable of reaching that low.

Do you guys have any advice on this? I thought about removing the timing cover and leaving the head in place, but that sounds like a major PITA. I guess the other option is to remove the head I JUST torqued to spec. Sounds like a PITA too, but maybe less than the timing cover. Any other ideas?

Any help is much appreciated. This is my daily driver and has been out of service for about a month now while I've been working on it. Was really expecting to finish it up today, and then this happened. Thanks in advance.

Will post some tips about the various jobs if/when I get this done.
 

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Wrong torque spec***8212;how much?
Bolt snapped above or below the threaded hole? If above then removing timing cover might not be possible.

Technically head must be removed to ensure a good seal between head/timing cover. If it were me I remove the head.
 

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Wrong torque spec-how much?
Bolt snapped above or below the threaded hole? If above then removing timing cover might not be possible.

Technically head must be removed to ensure a good seal between head/timing cover. If it were me I remove the head.
Plus 1 on this. That is really a tough area to access. I would hope the bolt snapped above the threaded part of hole so that when you remove the head you will have a piece of the bolt to grab onto to turn. That would be the proper way to do it.

Then again , how much sealing goes on in that area? Is the timing case under full oil pressure? The use of H8 bolts tells me not much. The head to the block is sealed by the two last head bolts. Its about the same work to fix it now as it would be afterwards. I might be tempted to see if it leaks.
 

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Have you looked at Mcmaster to find a long 'reverse' drill bit. If I tried that, I'd probably look for a sleeve to fit in your hole so as not to damage any threads down there...slip a drill bit inside the sleeve...maybe?


https://www.mcmaster.com/

Good luck!
 

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Have you looked at Mcmaster to find a long 'reverse' drill bit. If I tried that, I'd probably look for a sleeve to fit in your hole so as not to damage any threads down there...slip a drill bit inside the sleeve...maybe?


https://www.mcmaster.com/

Good luck!
This bolt is located at a tight corner of the head, and with the head still installed he might mess up the timing cover more and then more headache. Head out.

Think twice torque once.
 

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Just remove the head and do the job right,since the bolt snapped while tightening,the bolt will come out easy.now when a bolt snap when removing,now you have problems.
 

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Discussion Starter #7
Hey guys. Thanks for the feedback. I am just going to play it safe and remove the head. I'm hoping and thinking that there will be a few threads sticking out above the timing cover. Also hoping that I did mess up any of the threads on the timing cover when I tried to pick the broken bolt out. Unfortunately, I'll need new cylinder head bolts and gasket now since I'm removing the head again...Oh well, such is life. The new parts will be here tomorrow. Maybe I'll give it a shot tomorrow if I'm feeling unusually energetic after work lol. Thanks again for the advice.
 

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Discussion Starter #8
BTW, Effduration, it's not under oil pressure at the location in question, but it has a lot of water pressure from the water pump. The main inlet to the head passes through there. But, I don't know how much sealing those bolts really do: they are supposed to be torqued only to 89 inch lbs. IIRC (not 180 inch lbs, i.e., 15 ft. lbs,as the erroneous torque sheet I read earlier indicated). Yet, I am sure it is enough to make a difference. It would actually be a huge pain to fix if I put everything together and it didn't work***8212;you have to remove the intake manifold, fuel rail, throttle body, idle air control valve, electrical harness, etc. before you can remove the head.

I'm using a fel pro MLS head gasket. You guys have any thoughts as to whether I should use a sealing compound around the timing case portion of the gasket? When I originally put it on, I just did a dry seal. I know the Bentley manual calls for some compound, but I don't think it contemplates the use of an MLS gasket.
 

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Always use a think sealer at the seam on the timing cover/block.

7.5 or 8 ft lbs and not 15 ft lbs for those bolts.
 

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Hi, I did the same when I did my first head gasket job. Those 3 bolts are really brittle, never use a ratchet like i did, try get them hand tight with a normal T wrench or similar. The only way we got it out was by removing the head again, we then drilled the bolt and used a screw removal bit. Also when you remove the head, make sure you redo a Helicoil or T sert job with big inserts as removing the head bolts will likely mess with your new threads (I found out the hard way). Also make sure you helicoil the three E8 bolts to M6, it gives you great strenght as the threads may have been messed up when you overtightened. Good luck
 
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