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I'd try spraying a lubricant onto the threads and let it sit over night. These usually spin right out as there is no pressure on them. If that doesn't work, try tapping on the edge with a screw driver to see if it will turn. Do the simple things first.
Get some PB Blaster - penetrating oil for rusty bolts. Makes all the difference. They sell it at Home Depot. Then follow some of the suggestions about welding or slotting.
it snapped off cuz it is rusted in. pliers, easy outs, etc ain't gonna do it. heat the manifold with acetylene torch and it will probably work. Mig also works. or grind it flat and drill it and helicoil it. find a long bolt type gooseneck to use as a drill guide. find a boat place that works on mercruiser stuff and they will give or loan you a rusted out thermostat housing to use as a guide for a 3/8 drill bit.
Last edited by derekderek; Feb 19, 2023 at 02:34 PM.
dremel cutoff wheel too slot bolt for screw driver
Originally Posted by Tech141
A very small pipe wrench after applying some penetrating oil.....
Originally Posted by HeadsU.P.
^^^^^ This ^^^^^
Walmart has Dremel cut-off wheels only an inch in diameter. Go slow & steady, just barely make a slot without gouging the casting.
BUT... before trying to back out the broken bit, heat all around the bolt's boss with a propane torch to expand the manifold metal a bit. Try to keep the heat off the bolt itself. If you've used a penetrating oil, you'll get plenty of smoke, so ventilate well.
The broken fastener appears to be in an aluminum intake. Spray a little penetrating lubricant and let it sit. Take out the T-stat and draw down some coolant if you need to so that you can tape off the hole and effectively get heat around the bolt. Clean the manifold surface and tape off the hole. Center punch the old bolt and drill it for an easy-out (the set may suggest a drill size). Clean up, pull the tape and heat the manifold around the bolt and go for it. Worst case you reseal the opening, upsize the drill and replace the threads. Worst, worst, case you pull the intake and send it to Wilson in Florida and it will come back as good as new.
Heat and the "claw" portion of needle nosed Vice grips......the "claw" is the half round jaw part choked up on the tip.....get it as tight as possible....heat the **** out of the husing area with a MAPP gas torch....and back it out.......have the pliers already clamped on as you heat.....if it doesn't come off that way....you are grinding it flush and drill/heli-coil.....
The drill n easy out route is a trip to more headaches. Do ur self a big favor and take the manifold to a welding shop with tig capabilities. They will weld a bolt to the broken one and the combo of heat ( Al expands much faster than steel) and a new bolt head will spin the broken bolt right out. Once that is done, run a tap in both intake holes n clean up the threads.
That is how we in the aviation world handle those situations. Parts n time are too expensive to risk more damage n u damage the unit beyond repair.
Hi All,
Thank you for all the suggestions and advice on this issue! I was able to finally fix it this weekend.
We were able to weld a nut to the part of the bolt that was sticking out. After welding the nut to the bolt, it was pretty easy to remove.
The car is now running great and I got to take it out in some nice weather this weekend.
Thank you again!
Help Needed - broken bolt
