Has any one tried intermittent application of a spray lub, ie. PB Blaster,WD-40 to the spark plugs of these F150 engines that have the sticking/breaking plug problem over a period of weeks, with any luck ?
I have never needed to (anti-seize + regular inspection/replacement pretty much takes care of that). But there’s absolutely no reason not to do it. Go with the PB Blaster. WD-40 has its uses but its not really a good penetrating oil.
One of the main things to do when installing plugs in any aluminum head engine is to not overtighten them. Forget any torque specs that may be cited in the manuals.
With a non-gasketed tapered seat spark plug just run it down until it hits and nudge it a bit.
With gasketed spark plugs run them down until they hit and then nudge them maybe another 1/6 of a turn.
Use anti-seize on the threads and I agree, forget the WD-40. That stuff is good for plastics and rubber but not so good on metal.