Corvid Posted March 18, 2016 Share Posted March 18, 2016 (edited) Well kids, let this be a lesson to you. Don't indulge your insomnia by performing critical repairs at 3am, you might forget something small, like resetting your depth marker for drilling out your intake bolts. So, I had the rear intake bolt on each side of an EA82 snap off during careful removal. The stubs are completely chem-welded into the block, and multiple days of point blank heat gun, penetrating oil, left hand drill bits, cold chisel, etc failed. I cut the first one off flat , and noticed that the smaller drill hole was not center enough to keep drilling it out and Time Sert it. I used transfer punches in the manifold and checked their center locations against a factory gasket, and made a drill jig out of a 1 inch block of cold rolled steel on my mill. I bolted it up and it looked perfect. Thats when I failed to remark the depth stop, and plunged through the bottom of the intake bolt. If you are working on the head on a bench, this doesnt matter, because you will drop into air when you hit the passage for the headbolt. On the car however, you can cross drill a 1/4' hole allllllllll the way through the headbolt itself. Then you get to feel very smart. So, my inclination is to pull the engine, pop off the cam carrier, and replace that one damaged headbolt. Anyone with more engine experience see a reason this wont work? Or a reason why I shouldn't have to? Edited March 18, 2016 by Corvid Link to comment Share on other sites More sharing options...
Bantum Posted March 18, 2016 Share Posted March 18, 2016 (edited) Show us the damage & we might be able to work out what the next move is ... Add : It'll depend on how far you drilled through it - Bolts can be replaced, but If you drilled through any water passages ... :/Ciao, Bantum ... Edited March 18, 2016 by Bantum Link to comment Share on other sites More sharing options...
DaveT Posted March 18, 2016 Share Posted March 18, 2016 I'm not sure about what to do with the head bolt as far as remove and replace. But if yo decide to try to remove it, get the block up to near normal operating temperature with heaters and a heat gun. Meat thermometer or something to monitor. I have removed many very stuck bolts intact with that method. It has not failed. Once a bolt is snapped, my next trick is weld a nut or washer to the stub, then unscrew. This I learned before the heating the block trick, but it works once the damage has been done. I mention these also to possibly save others trouble if they read this before snapping a bolt... The drilled through headbold may fail where it was drilled, so you may be removing the head.... Link to comment Share on other sites More sharing options...
Corvid Posted March 18, 2016 Author Share Posted March 18, 2016 The drilled through headbolt may fail where it was drilled, so you may be removing the head.... Oh, I know. This was supposed to be a Weber Swap, and its ending up more like the beach scene in Saving Private Ryan. It's not my first rodeo, but some jobs just have the curse. I'd love someone to explain to me why I haven't compromised the holding strength of the headbolt, and that I should leave it there. 1 Link to comment Share on other sites More sharing options...
Bantum Posted March 18, 2016 Share Posted March 18, 2016 (edited) That will depend on how much 'meat' there is left in the headbolt, how far did you drill into it ? P.S. - Got any photos of the damage ? Edited March 19, 2016 by Bantum Link to comment Share on other sites More sharing options...
TomRhere Posted March 18, 2016 Share Posted March 18, 2016 Did same on my 1st ever "drill out the broken intake bolt" on a Subaru engine. I'd replace the bolt. You have removed a good portion of it's meat so to speak. 1 Link to comment Share on other sites More sharing options...
Corvid Posted March 19, 2016 Author Share Posted March 19, 2016 For anyone that missed it in the first post, I drilled all the way thru the headbolt. There isn't a coolant passage that I am aware of in jeopardy. What's even better, is that the intake bolt hole is slightly offset to the headbolt through-passage, which means I didn't cross drill the headbolt in the middle, but just barely wiped out one edge of it. What are the odds getting THAT out without snapping it off? If I hadn't ruined the headbolt, this would be a triumphant day. By making a drilling jig to core out the center of the broken intake bolts with a 1/4" drill, I was able to leave just the bolt threads hanging out in the block threads. I twisted a few coils out with a pick and needle nose pliers, and than carefully ran a M8x1.25 BOTTOM tap down the holes. If you do this, use thread cutting fluid and a real High Speed Steel tap, not some grey carbon-steel trash from Ace Hardware. Saved both the holes, pretty as a daisy, no Time Serts. Link to comment Share on other sites More sharing options...
frankenwagon84dl Posted May 11, 2017 Share Posted May 11, 2017 I was putting the heads back on my EJ22 and snapped head bolt #3. I got brand new fel pro bolts and gaskets. My manual said to torque to 22, 51, back out 180˚, back out 180˚, then torque the middle 2 to 25, then start on 3,4,5,6 to 132 for non-turbo. I can't seem to figure out where I went. Thoughts, suggestions? Link to comment Share on other sites More sharing options...
DaveT Posted May 11, 2017 Share Posted May 11, 2017 Welcome to USMB. EJ is a newer generation engine. You will likely get more replies for this question in that sub forum. Do you have a factory service manual? There are links on a lot of new gen forum threads to online ones. Probably best to start a new thread, rather than adding to a year old one. Link to comment Share on other sites More sharing options...
idosubaru Posted May 11, 2017 Share Posted May 11, 2017 I'd use used Subaru head bolts before aftermarket head bolts. You're saying one head bolt broke right? 1. Chase the threads first with a tap before installing the head bolts. Pay particular attention to the bolt hole that snapped. 2. Carefully oil the threads - not so much that it pushes out and runs everywhere. 3. Thread the bolt by hand without the head first so it's not under any tension and see how easily it installs. 4. Verify your torque procedure 5. Verify the units you're using - are you converting or how does your torque wrench read? 6. Test or calibrate your torque wrench. How old is it? Link to comment Share on other sites More sharing options...
idosubaru Posted May 11, 2017 Share Posted May 11, 2017 I'd love someone to explain to me why I haven't compromised the holding strength of the headbolt, and that I should leave it there.Wish I had seen this last year. No way I'd worry about or touch it. That headbolt isn't going anywhere nor going to "give up" any tension or cause any issues. I mean look at your intake bolts - they're screaming at you that there's no chance those bolts are giving any ground without specific focused applied forces. I'd love to hear what you ended up doing. Link to comment Share on other sites More sharing options...
frankenwagon84dl Posted May 11, 2017 Share Posted May 11, 2017 Sorry about this. It appears I misread the inch-lbs step. Thanks for all the help Link to comment Share on other sites More sharing options...
idosubaru Posted May 11, 2017 Share Posted May 11, 2017 Sorry about this. It appears I misread the inch-lbs step. Thanks for all the help At least you caught it and figured it out. I'd chase all the threads and clean them up incase any were compromised. Link to comment Share on other sites More sharing options...
Craigar Posted September 1 Share Posted September 1 93 Loyale SPFI.. the back long bolt driver side intake manifold bolt is stuck / frozen - and so are the 2 long ones on the passenger/left side also... I havn't broke them off ( yet ) .. any easy way out? thanks all Craig Link to comment Share on other sites More sharing options...
Steptoe's photos Posted September 1 Share Posted September 1 two scenarios - either the shank of the bolt is fused to the intake manifold or the threads in the head are stuck. With first possibility, can you drill through the side of the intake manifold up high, in order to get some spray lube straw into the corrosion cavity ? I find when fitting shaved heads, I need to enlarge holes in manifold to make up for shaved amount - gives greater cavity, less chance for corrosion. Or tape up bolts in teflon tape. Threads get the copper grease. Shame the last person in yours not have copper grease. Link to comment Share on other sites More sharing options...
Craigar Posted September 2 Share Posted September 2 11 hours ago, Steptoe's photos said: two scenarios - either the shank of the bolt is fused to the intake manifold or the threads in the head are stuck. With first possibility, can you drill through the side of the intake manifold up high, in order to get some spray lube straw into the corrosion cavity ? I find when fitting shaved heads, I need to enlarge holes in manifold to make up for shaved amount - gives greater cavity, less chance for corrosion. Or tape up bolts in teflon tape. Threads get the copper grease. Shame the last person in yours not have copper grease. Thank You! The little plate under this particular bolt can move so the head isn't stuck at least not to the top of the landing (don't know about passenger side yet) and I also thought of the "drill a hole for the spray lube straw into the corrosion cavity" sounds like a really good option! I started a new topic here https://www.ultimatesubaru.org/forum/topic/186067-any-new-ideas-for-the-old-intake-manifold-stuck-bolt-problem/ Link to comment Share on other sites More sharing options...
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