I'm really surprised to see a stripped pan thread, as the hollow bolt usually breaks so easily (so I've been told). Some ham-fisted clown must've cross-threaded the bolt going back in (likely breaking off its head) and then did an amateur job with the Heli-coil.
Originally Posted by JayMac
I am in the process of sorting out an s54 for an engine swap to my e36 and came across this thread. Dropped the pan today in advance of rod bearing job and discovered I have a pan that has been helicoiled.
I am trying to get the plug out but it does not want to move. How much torque will this thing take? Any ideas, maybe a little heat or just more slow steady pressure?
If you're dead-set on doing it right, drill out the bolt, it should be soft enough, staying exactly on the hole's centerline. Once the bolt is out of the way, you can unravel the insert by pulling/unwinding the HARDENED steel coil from the inside of the pan.
Take care that your unraveling process does no further damage to the threads, or you'll wind up with too big of a hole and have to go up a size for the drain plug.
The insert should not extend beyong the aluminum casting, and should've broken off "square" to allow the bolt to pass through the end of the insert__that's what likely jammed up the installation you have before you.
Or take Terry's advice and put the whole thing out of your mind, commiting all future oil services to be done with an extractor...
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Last edited by Randy Forbes; 10-28-2012 at 07:12 AM.