Unfortunatly when all the glow plugs are burnt out it makes me a little suspicious Tom. For starters the glow plug relay may be coming back on.I would either monitor that or if I had a spare good relay around the garage exchange it. . I would also ream the plug holes for potential excess carbon build up in that situation.

Fortunatly in your case the plugs just aged out or the filaments just wore out out so to speak. So no ongoing concerns at all. Nothing lasts forever.


Unfortunatly it is not a record either. There is no reason to despair though. Since there is no tangiable reward or recognition for holding the record. What does it really matter? The only trophy just might be the burnt out award. At our approximate ages who really needs that particular one?

In ancient times we were taught that filaments and cathodes had finite lives. Efficiency just falls off with time and use. Probably the repeating on/off cycles oxidized the filaments impairing their ability to boil off or transfer electrons.

In a glow plugs case if the fundemental resistance was still very low The slowly developed coating or changes might act as a restriction to the electron/heat transfer. Or perhaps the very nature of the metal filament is changed with time and use. So the plug will not glow red.