How do I remove a broken spark plug?

[Farrar]

Can't believe there isn't a thread here already, so I'm starting one.

Technically, I don't have a broken spark plug stuck in the engine. What I have is the end of a compression tester stuck in the engine. Technically, though, it's the same problem.

The internet is full of advice on how to remove broken spark plugs from truck engines, but nothing for the PRV. I can't find anything long and skinny enough to get down in there and grip what's left of the thing.

Suggestions?

[opethmike]

Can you post a picture of it? It could be broken off in a bunch of different ways.

[David T]

This is potentially harder than the removal of a typical broken spark plug. With a spark plug you have some idea of what you are dealing with. There is no good way to grab anything in that well. Not too many ways to deal with this. The best bet might be to take the head off and have a machine shop deal with it. With the head off maybe you can get an "Easy Out" or something and try turning it from the other end? Worst case you punch it out, destroy the threads and fix with an threaded insert.

[Ron]

+1 on a pic!

Seems you might use an Easy Out as is, i.e. w/o removing the head...

[Farrar]

OK, here's a pic.

Attachment 58401

The hole is where the air goes through to register on the gauge. It's dead center, so that might be as good a place as any to put a drill bit. I went to the hardware store and asked for a long drill bit, but they suggested I buy a drill bit extension instead... which they didn't have in stock... so I ordered one online. In the meantime I bought a screw extractor set, but none of the bits is long enough to reach down in there. I guess I will have to wait for the extension to arrive.

Thanks, y'all.

[Ron]

fwiw, most Easy Outs have a square head on them, which would fit a 12 point socket....

I wouldn't drill it unless I had to because of the metal shavings that might fall into the cylinder (depending on how the tester end was made...).

[Farrar]

depending on how the tester end was made...).

If memory serves, at the bottom is a check valve. Assuming I don't drill into the valve,

... but what am I saying? I'll definitely screw this up. After all, I couldn't manage a simple compression test without turning it into a disaster.

Thanks for the tip.

[dn010]

So don’t run the motor then. But find a way to heat the head up. Heat makes things much easier to remove.

[David T]

No good way to get the heat where you need it unless you remove the head. I agree heat can help but only if you can heat the right part. That part is only supposed to be hand tight. I can't believe it is so stuck that some tapping and prodding can't get it loose.

[Ron]

So don’t run the motor then. But find a way to heat the head up. Heat makes things much easier to remove.

FWIW, spark plug manufacturers and shop manuals all have warnings to let aluminum heads cool before removing the plugs...