5.4 3 Valve missing tip of the spark plug

Mekanik · September 7, 2013

Has anyone ever extracted a 3 valve spark plug on a 5.4L and find thet the tip of the electrode has broken on both sides and is missing? :ohnoes:

I've had plenty break where the electrode is broken on one side, but it doesn't break off. I blew air in the cylinder several times, blew shop air throught the exhaust pipe and out of the spark plug hole. I can't see it in the cylinder I'm hoping that it came out with the compressed air.

Jim Warman · September 7, 2013

Only suggestions I can come up with include a remote viewer (much cheaper now I have purchased my SeeSnake for way too much). Also, turn the motor over by hand several times. After that, the customer can roll the dice on the decision to fire it up and see what happens. There is every chance that the resulting crap has already passed from the motor - how often do you see a motorist turn it off st the first sign of trouble? Right!! drive it till it don't move is the norm.

You didn't design it, you didn't build it and you didn't break it.

Matt Saunoras · September 7, 2013

Many times with the lisle tool. Yes there is always the chance something will end up where it shouldn't, no it hasn't happened yet.

Mekanik · September 8, 2013

I was able to look in the cylinder with the boroscope with a limited view because the plug hole is so narrow. I blew it out really good, both from the spark plug hole and through the exhaust pipe. With air blowing into the cylinder through the exhaust valve If it was in there I should have seen it blowing around. I ended up satisfied that the teeny piece of metal was no longer in the cylinder, put a new plug in it and it was fine.

Yeah, I use the Lisle tool too. I like it but I think the tool that presses the porcelain down has a tendency to break the electrode and porcelain.

Fredsvt · September 10, 2013

I've seen it in a fleet truck, 200k on a 5.4 3v. The number 1 plug LOOSENED and backed out just enough for the thing to start detonating and it blew 3/4 of the bullet end off the plug, then started missing when the coil boot burned up from the combustion.

The plug screwed right out, new coil and plug, checked all the rest of them, all were loose, (replaced) and it's still going down the road.

Matt Saunoras · September 11, 2013

Yeah I have seen a handful of loose 3v plugs. The telltale brown combustion stains and the boot will smell pretty bad. A few were so loose half the plug was melted away.

mrbudge · September 11, 2013

I have also seen loose plugs in the 3v engines, always after someone's buddy changed them because I dare to expect to be paid to work. I find even if they are just a little loose they can cause a misfire at high load/rpm.

If I have broken porcelean in the spark plug I use a tool that I made up to chip some of it out before pushing it down and cutting threads.

This prevents the electrode from breaking off.