911 Sparkplug Replacement

[E Sully]

I've seen a lot of corrosion on old wires that did not have dielectric used. In one case on my friends '87 there was no way to get the wire off the coil, and it had to be replaced.
http://forums.pelicanparts.com/porsche-911-technical-forum/1127313-ignition-coil-wire.html
I use a light dab of dielectric grease on the ends. If not installed carefully with a firm push, air can get trapped and the boot will tend to push off.
As far as anti seize, Porsche recommends it, here's a TSB. I use NGK spark plugs, and they don't recommend anything when new. According to the website, the threads on NGK's spark plugs already has these properties. When reinstalling I would use it, but not when new.

[PeteKz]

How may Pelicans does it take to change a spark plug?

One to do it. And another dozen to advise on whether/what anti seize to use.

[PopsRacer]

FWIW.[anecdotal]. I have a friend who works for a big automotive supplier and who focuses on connectors. Takes part in lots of reliability testing He is a big fan of Nyogel for places such as inside the spark plug boots, or the crank sensor plugs, etc. He’s seen water creep up into all kinds of connections. The gel does not conduct current, but it keeps out water/moisture. It does not interfere with the electrical connection (there is plenty of metal on metal contact) It’s incredible to me that the insides of these things corrode, but I would bet we’ve all seen it happen. I use it on my engine grounds as well. I guess time will tell.

re: plugs - I have also had good results with the magnetic gearwrench socket (there is a set of 3 wobbley plug wrenches btw), and there is also a neat tool from Hazet (#2505-2) which has 3 different depth settings. I really like the factory tool, but had the rubber bit stay on a plug once and ngl, it really tripped me up. I glued it back in with 3M black weather seal adhesive. We’ll see how it goes. I think I am leaning towards the magnetic ones for now…

[85RedCarrera]

You are screwing steel spark plugs into aluminum threads…it is the aluminum that is wearing/moving every time you remove and replace. After some time in the head, if you don’t use any product on the threads, the plugs will cause dissimilar metal corrosion of the aluminum threads and they will be difficult to remove, which means you are wearing/damaging the aluminum threads even more when you apply more effort to remove them.

Aircraft heads and motorcycle heads are the same - aluminum threads. Always use a lubricant with spark plugs going into aluminum threads. The old way was using a drop of oil on the spark plug threads. Anti-seize, if applied should not be applied to the last two threads, to avoid contaminating the electrode (which is a real thing). If the manual says lubricate the threads and gives a torque value, and you are not lubricating threads, then you are not torquing the plugs to the specified torque value- you are simply torquing until you reach a thread friction value.

These old heads are getting rarer every day- do the next guy/gal a favor and lubricate your spark plug threads. Every time. Clean the spark plug threads after removal, and lubricate the threads before re-installing.

At the very least, put a drop of oil on them before re-installing. There is nothing to be gained by installing plugs dry, except that they might be less prone to loosening- but if you lubed clean threads and used a torque wrench, wouldn’t loosen anyway. My .02 from a lifetime of working on air cooled motorcycles and aircraft engines.

FYI- Molykote is the good stuff….