On Thu, 27 Jan 2005 13:45:42 -0600, (James
Goforth) wrote:

> I'm sure most of the guys in here would have an opinion about your
>mentioning that the plugs don't need service for 100,000 miles; here's
>mine FWIW:
>
> Aside from the obvious risk of not being able to get the old ones out
>after 100K; also by this time the gap in them is wider than hell,
>shortening the life of the coil as it's working way overtime trying to
>fire across that way-too-wide gap, and of course by this stage of the
>game the vehicle is out of warranty so you're buying coils and etc as
>well as hassling with the busted off plug(s)...
>
> In other words, anyone who suggests that you don't need to change
>plugs until 100K...FORGET THAT! :-)
>
> Just my 2ç
I agree with you, forget 100,000km plug shanges - but not because of
the gap with P2 plugs (platinum center electrode and ground) it is
surprizing how little the gap changes over the 100,000.

The big risk is thread siezure. Compression seal leakage is still an
issue on some plugs (the expensive critters with the German name) and
insulators crack, glaze, and deteriorate too.

When you loosen the plugs and apply antisieze, use it judiciously, and
put silicone dielectric compound on the plug boots too, to keep
moisture out and keep them from "vulcanizing" themselves to the plug.