Date registered: Jan 2007
Vehicle: 1962 W111 220SE Coupe
Location: Cloud City, OR
Mentioned: 1 Post(s)
Quoted: 8 Post(s)
Spray a penetrator (WD40 or similar) and go have a snack while you let it do it's work. If the stripped head cannot be grasped at all by a smaller diameter socket or a specially made tool for extraction, or vice grips if it's already mangled. Some have suggested cutting a slot using a hack saw to put a screwdriver on but I doubt that will work if they are solidly in place.
You could also try warming the whole area again and then immediately hit the bolt head only with a spray of supercold compressed air. If you get right on it there may be enough shrinkage to the bolt to remove it. You would spray the bolt head with compressed air (the kind you use to clean keyboards) held upside down but DO NOT inhale the vapor or let it touch you as it is extremely cold and will cause damage quickly to skin and lungs. Spraying upside down will send cold liquid rather than air as you would get holding the can upright, and the liquid will begin to evaporate quickly. I'd try this as a last resort so you don't risk a fire or cracking the case due to temp changes, I'm assuming it's made of cast aluminum?
Whatever you choose to do, have spare plugs on hand so you won't be putting the same old ones in again.
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