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Old 03-08-2013, 05:01 PM
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JCL JCL is offline
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Originally Posted by lordshin808 View Post
Why is applying anti-seize on the plugs NOT recommended? I thought the you're suppose to apply it so the plugs don't get stuck in there.
1) Too much gets on the electrode.
2) The effective heat range of the plug can be affected by the conductivity of the paste (plug to block)
3) The plugs already have an anti-seize coating. If it is a very old plug (black, no silver threads, no label indicating anti-seize) then this doesn't apply.
4) Anti-seize changes the effective torque spec. Lubricated threads reduce the friction, so the plugs go in further (against the crush washer) up to when you hit the torque spec. That means they sit lower, and the exposed end can get deposit buildup. That is what can cause seized plugs. If using a lubricant/anti-seize paste, then reduce the torque spec. There is a reason that all the torque specs are usually dry specs, though. BMW, most automakers, all the major plug manufacturers, all recommend not to use anything on the threads. Lots of home mechanics (and some professional mechanics) think they know better, though.

I leave them dry, I don't overtighten them, and I don't get seized plugs.
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