Spark plug replacement time....

[Steve Tinker]

Ahhh - back to that thorny question of using / not using anti-seize on the plug threads.
I do, but Porsche says not to.......

[JFP in PA]

Originally Posted by Steve Tinker

Ahhh - back to that thorny question of using / not using anti-seize on the plug threads.
I do, but Porsche says not to.......

Porsche's rational for that has to do with the type of anti-seize compounds that used to exist vs. what you can get now. Old types were not particularly electrically conductive, which could lead to misfires because the plugs were not properly grounded; new types are metallic (usually copper or aluminum based), which are conductive. Use a small amount of anti-seize and your cylinder heads will thank you. We have been doing it for decades and have never had a misfire, a plug come loose, or one pull the threads out of an expensive cylinder head..........

[lkchris]

More to the antiseize story ...

Published tightening torque figure assumes dry threads.

Antiseize is a lubricant and you'll have no idea how tight you get them but it will be over tight and risky unless you adopt a lower spec.

[JFP in PA]

Originally Posted by lkchris

More to the antiseize story ...

Published tightening torque figure assumes dry threads.

Antiseize is a lubricant and you'll have no idea how tight you get them but it will be over tight and risky unless you adopt a lower spec.

Not really; fastener manufacturer's like ARP have published several white papers on the subject of dry torque inaccuracies when compared to using different lubricants; in every case, a lubricated fastener was correctly torqued while the dry fasteners were not. Lubrication aids in obtaining consistent torque values, not detracts from it.