Originally Posted by larrie
I would be more worried about the bolt being frozen to the threads. If they are it is possible to damage the intake manifold that the threads are pressed into. If the damage the intake manifold solution is to either replace the manifold or epoxy the threads back into the manifold.
Bottom line is be careful. To much leverage is you enemy.
Correct---all of the above.
Every time I remove a COP bolt successfully I'll use a dab of aluminum anti-seize or dielectric grease is applied to the threads. When tightening them I use a 1/4" drive hand ratchet only---there's no need to crank them down to some insane torque value. Using the hand tool and lubricant helps avoid cross threading which can cause the brass insert to loosen and no longer hold the COP tight against the spark plug.
As Larrie says the COP bolt threads are pressed or heated and then installed in the plastic intake. Long time between plug changes or heavy handed installation is the main culprit when those inserts become a problem. Replacing the intake is one way to do it but if you're able to remove the bolt and insert without damaging the intake you can re-install the inserts like this:
FWIW the COP bolt thread is M5 x0.8 pitch.
You can also use Loc-Tite's thread repair system which is suitable if done correctly.
Removing a spinning COP bolt would require drilling the head with a large enough bit to eliminate the entire bolt head. The OEM bolt with integral flange or washer is about 11MM or 13/16" in diameter. You could also CAREFULLY cut the COP mounting tab off to remove the coll and deal with the bolt and insert at that point. Naturally this would necessitate replacing the COP--use nothing but Motorcraft please.
Here's two photos of the COP's as they'd appear installed:
With bolt in place:
If drilling the head away drill use increasingly larger holes to help center the largest bit required to remove the COP without damage to its case.
So that's what I know---hope its helpful.