rich_e777 Posted July 6, 2013 Report Share Posted July 6, 2013 Finally nailed the source of an exhaust leak, rear manifold cracked due to lack of flexible joint in exhaust pipe, also the last bolt has had its head broken off for what seems to be a good long while. Got a new manifold and gasket and now trying to get that bolt out. Problem is a drill doesn't have clearance and welding a new head on it hasn't worked, cars in a shop right now and they cannot get at the bolt either. Other than pulling the head off is there anything else some of you guys can think of? Thinking about just leaving it and patching the area around it with this stuff I got at AZ for exhaust repair, ideas? thoughts? funny comment? all appreciated. Quote Link to comment Share on other sites More sharing options...
Schurkey Posted July 6, 2013 Report Share Posted July 6, 2013 (edited) Remove crossover pipe, exhaust pipe (downtube), remove all other bolts and perhaps O2 sensor. Pull cracked manifold as far away from head as possible. Reach between manifold and head with vice-grips, unscrew broken bolt. Thinking about just leaving it and patching the area around it with this stuff I got at AZ for exhaust repair Only if you want to waste time, money, effort, and enthusiasm. Edited July 6, 2013 by Schurkey Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted July 6, 2013 Author Report Share Posted July 6, 2013 Not enough of the bolt is left to get at with vice grips. I think between the 20 years of heat and rust its fused in there. Would drilling/tapping the cylinder head work or would getting a new head be the way to go? Quote Link to comment Share on other sites More sharing options...
Schurkey Posted July 6, 2013 Report Share Posted July 6, 2013 (edited) Not enough of the bolt is left to get at with vice grips. I think between the 20 years of heat and rust its fused in there. Would drilling/tapping the cylinder head work or would getting a new head be the way to go? The HEAD of the bolt broke off, or the SHANK of the bolt is damaged? Heat the cylinder head. Aluminum expands more than iron/steel. You warm it up, the bolt should come out fairly easily. Some folks suggest candle wax as a lube. Others soak in penetrating oil. (I wouldn't bother.) If the threads in the head are damaged during removal, a heli-coil or competing thread repair insert should fix it. That may require head removal, depending on working clearances/tool access. Edited July 6, 2013 by Schurkey Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted July 6, 2013 Author Report Share Posted July 6, 2013 At first it was just the head, once the manifold was off it appeared that some of the shank was damaged as well. So vice grips didn't work, After that to the shop the car went and the guys there tried welding a head on it and after a few hours of cooling off and soaking in yet more PB and heating the cylinder with a torch that head twisted of as well taking the exposed shank with it. I think everyone is in agreement now that to fix it properly the cylinder head has to come off. Fine will do but in the meantime I need my car to work to pay for things to fix said car with. So we went with leaving it for now and going with the exhaust repair stuff which will handle the temperature once it cures up for the week end. The exhaust guy said it will work fine, he has done it before, the manufacture VersaChem says it more than handle the application so thats what Im going with for now. Will see how it goes this next week. Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted July 7, 2013 Author Report Share Posted July 7, 2013 Ok the stuff has had time to cure and its hardened up. Can no longer hear the car when its running and the only indication of the engine running is the Tach. No longer smelling exhaust in the cockpit or when the hood is popped for that matter. Idle has smoothed out, power has increase slightly. I don't particularly trust the repair 100% yet but for a temp fix until I can pull the engine apart this has worked awesomely. Hopefully the manifold will come off without damaging the head where this stuff is. Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 28, 2013 Author Report Share Posted September 28, 2013 Getting ready to re gasket the engine and I want to properly fix this embarrassment. I will try to save the cyl. head and attempt to remove the bolt. Considering the need to maintain torque specs, would drilling the old bolt out and re tapping the head be a good option or just replacing the cylinder head be better. If replacing the cylinder head would I need to replace both and can I get away with using ones pulled from a lower mileage 3100? Quote Link to comment Share on other sites More sharing options...
Schurkey Posted September 28, 2013 Report Share Posted September 28, 2013 IF (big IF) there's nothing else wrong with the head, removing the broken bolt and repairing the threads with a heli-coil (or similar) thread-repair insert would be all you need. Depending on mileage, you might want to freshen-up the valve seats and faces, check the valve guides for wear, and replace the valve stem seals. (i.e., "Valve Job") You may need to plane the head deck surface to assure that it's flat and smooth. Hopefully you don't need to plane the block deck surfaces. BEFORE you pull it apart, perform a leakdown test on it so you know if the valves are still sealing. Other (junkyard) heads may be better--or worse--than what you have now. Be sure to verify that the replacement heads are properly interchangeable with what you have now. Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 28, 2013 Report Share Posted September 28, 2013 Be a good time for a 3400 topswap Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 28, 2013 Author Report Share Posted September 28, 2013 That would be the desired route, cobbling together workable parts might work for an Ak-47 but not a 3100 v6. 125K-ish is the mileage, about 65k all me. So most defiantly will be going over every little nook and cranny to remove build up and maximize airflow. Thanks for the advice, will do the leak down test too, planned on a compression test as well. Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 28, 2013 Report Share Posted September 28, 2013 Might wanna do a lil more research on 60 degreev6.com you might find that "cobbling" 3400 parts onto a 3100 more than works fine Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 28, 2013 Author Report Share Posted September 28, 2013 Negative, I want to get the engine in good working order first, do my suspension job and then I got some major bodywork to do on the front end and on the driver`s side rear wheel area. I need the reliability of the engine right now instead of power, once my finances get back in order I plan on swapping powerplants. Which one and how it will be sitting is still debatable. Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 28, 2013 Author Report Share Posted September 28, 2013 Might wanna do a lil more research on 60 degreev6.com you might find that "cobbling" 3400 parts onto a 3100 more than works fine I am familiar with 3400 top swapping and 60degressv6.com. Future plans include an engine swap but to something that's not so fire prone like the L67. Quote Link to comment Share on other sites More sharing options...
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