I was helping my brother do some routine (hah!) maintenance on his 92 Camry 4 cylinder. I offered to change the spark plugs and wires for him. What a disaster! In my attempt to remove a spark plug, I broke the plug off. Now, the porcelain DID NOT break, but the steel threads that screw into the head DID break.
Two mechanics have tried to back it out using an easy out without success. I figure the spark plugs have been in there many years without changing. I feel guilty about this since I should’ve just left well enough alone, but I don’t want to have to remove the head to solve this. What other tricks are there? No mechanic is readily willing to drill the plug out and use a heli-coil to repair it…
Help!
Do feel guilty about this. It is not your fault and happens to even the best mechanics.
A prime example of why I consistently whine on this board about not leaving plugs in place for eternity.
I’ve had to wrestle a few like this and sometimes there is nothing on earth going to free the plug from the cylinder head threads.
What I would do is drill it out in stages. Apply heavy grease to the drill bits and continue to remove the bit and clear the metal shavings off the end. Continue to work your way out with larger bits until you’re near the threads.
Take a pin punch and gently tap the side of the threads in to see if the remaining thin shell will collapse on itself. Attempt to remove the shell with some stiff needlenose pliers, etc.
Now, I know you’re wondering about any possible metal filings, pieces of porcelain, etc. dropping into the cylinder. Not to worry. Stand clear and crank the engine over. If there’s anything in there it’s going to either vaporize, blow out past the exhaust valve, or out the spark plug hole.
Of course, make sure you have the majority of the old plug in hand before doing this.
If the threads are ruined anyway then there are several methods of thread repair; Heli-Coils, etc. JMHO anyway.
Try PB BLASTER penetrant on those threads. Get a REVERSE drill bit just a little less in diameter than the spark plug threads. The action of the counter-rotating drill bit could help the thread shell to turn out of the head. Where to get one? Try auto repair shops, run down one of the tool supply trucks (such as Snap On) which go from garage to garage. Or, call a tool supplier in your area. A Granger store in your area may have one. Good luck.
I second the PB Blaster and would add Sea Foam Deep Creep to the list. After an overnight soak, you might try heating the plug with a propane torch. If you get it out that way, be sure to use a silver colored anti seize on the new plug threads unless the new plugs come with an anti seize plating.
i HAD THE SAME PROBLEM WITH AN OLD VEGA. i USED A HELI CIOL TO SLOVE THIS THIS. BUT REMEMBER THE COIL WIL COME OUT IF YOU RPLACE THE PLUG DO NOT OVER THIGHTEN THE PLUG OR YOU TURN COIL AND IT WILL POP OUT. i WOULD TRY TAP THREADS AND MAKE A LARGER SIZE AND LOOK FOR A LARGER SIZE PLUG
THAT WOULD WORK. AN OLD PLUG IS BIGGER AND MIGHT JUST WORK. AT ONE TIME THEY SOLD AN ADAPTER YOU WOULD PUT IN HOLE AND MOVE THE PLUG BACK TO ADVOID OIL FROM GETTING ON THE SPARK PLUGS IF YOU HAD AN OIL BURNER. FIND ONE FOR OLD SIZES TAP HOLE FOR THIS AND USE THE FACTORY PLUG.LOOK ON
JC WHITTEY THEY HAVE HAVE ODD ITEMS