Originally Posted By: Kira
Hello, Could someone please explain what "two piece plugs" are if at all possible?
Sparky-poos haven't changed in 80 years. Why now?
Is the sleeve portion more like a heat shield?
I will look on RockAuto as well as Google it to see.
Super odd and stupid for any car company to complicate spark plug design or create installation difficulties.
Also, the blowing out of plugs I've read about....who are these fools?
My friend bought a 1997 F-150 with the 4.6 last year with 50K. Trying to learn about the truck. Kira
The launching plugs are on any '03 or older 2V modular including the 4.6L, 5.4L and 6.8L V10. There are only three threads holding the plugs in the heads and when you change them the threads get damaged and then the plug can later eject with the threads. Usually the plug backs out a bit first and you'll hear what sounds like an exhaust leak. It isn't. Sometimes you can get away with re-torquing the plug that has backed out, other times, it'll later eject. I've had both happen. #4 (worst plug on the engine) which has the rear A/C and heater lines running over top of it (which drops condensation down on it, which doesn't help) came out on me, so I put it back in. 30 days later it dramatically launched. I had another plug on the engine get a tad loose (#6 IIRC) but it torqued back down fine and it has been years. All the plugs were changed at the same time and torqued to the value prescribed by Ford.
The 2V is generally bulletproof aside from this issue.
The 3V, which came later, has a unique spark plug design due to the plug's location. It has a long "reach" into the combustion chamber, which required the bottom part of the plug to be extended:
The extended part on this particular plug had a tendency to accumulate carbon on its shank, seizing it in the head. When you went to remove the plug, the threaded portion came out, but the lower portion broke off and remained in the head.
The Champion "one piece" plug mentioned earlier in the thread looks like this:
And doesn't suffer from the same issue. I believe the Motorcraft plugs were also redesigned to alleviate it.
The 3V is also notorious for cam phaser noise but this is generally regarded as a nuisance and doesn't affect the longevity of the engine, despite hattaresguy's post. He has an obvious disdain for the engine family which doesn't reflect their actual service life.
Both issues can be seriously annoying/inconvenient, but once fixed, the engines generally live extremely long lives. Unless of course you are GHT and thin a 0w-20 down with 25% solvent, beat on it like a red-headed step child and then act surprised when you cook a rod bearing