Sparkplug electrode broke off inside combustion chamber.....

[HoosierSX]

Last week i was doing some spirited driving and after a 2nd gear pull my engine started knocking, it sounded like someone taking a hammer to my engine block.After i limped it home, I then removed the spark plugs and noticed the sparkplug from piston #3 had broken its electrode. After i replaced the broken plug with a good one, the engine ran fine, but noticed a faint rattle which sounded like the broken peice rattling around. Today I took off the exhaust manifold and turbo off the engine hoping i would find that little peice, but i didnt. Has anyone had this happen to them or to anyone they know? should it just pass through the engine and turbo without more damage? any pointers?

[assassin7420]

I would fish it out, If its the metal part get it with one of those bolt pickups. (think car antenna with magnet on the top.) That or use an air gun and try to blow what evers in there out.

Now that im thinking...... Rig a small hose to your vacuum cleaner. Vacuum the cyl out.

[HoosierSX]

tried like hell to fish it out using one of those antennae things with magnet on top. I also blew compressed air through the exhaust port with the intake valve closed, exhaust valve open all the way. also blew compressed air all though the turbo and manifold and didnt see anything come out. i even used one of these tiny cameras to look into the combustion chamber, piston and exaust port and still didnt see anything.

ill try the vaccum idea tomorrow

[kouki munster]

Hell, I melted the tip off my #2 spark last night, popped a ring land to.(23 psi, 400 whp, stock sr bottom end, and a a sudden lean condition that I'm still trying to figure out what caused it)

Pop out the plug and use a flash light to have a look in the cyclinder to see if you can see anything. Also a compression test would be a good idea because spark plugs don't just loose tips randomly, and what ever took out the tip could have possibly done other damage.

Edit: If you used the little camera to look around and didn't see any thing then its probably not there as there aren't really any places for the thing to hide.
Modified by kouki munster at 1:47 AM 9/4/2009

[HoosierSX]

just fyi, only about this much of the plug broke off.

[kouki munster]

The plug I melted is missing about that much to, hang on I can get a pic.

[mattblancarte]

Hmm... You'd figure that a vacuum would be weak in comparison to the compression of the cylinder. Wouldn't the bit have already been sucked out when the exhaust valve opened?

How do the fan blades look on the turbo? Any shaft play or anything? If the bit flew through there, it may have caused some damage.

Maybe the bit smacked the exhaust valve on the way out? Who knows lol.

[kouki munster]

9 times out of 10 when the tip of a spark plug goes, it melts and is harmlessly blown out the exhaust. My car for example ran just fine(only had a slight random miss with the melted plug still in it) and still does other than the low comp. on #2 causing the idle to be a little unstable.

[HoosierSX]

There was no shaft play and the blades looked perfect on the turbo. but my plug didnt look as bad as that, it looked to have broken clean off

[kouki munster]

That plug went out under under extreme conditions, full throttle, about half spooled, 4k, and an unexplained 15:1 afr, it bucked and popped twice before I could let out. I figure the first pop/buck killed it and the second one was just makeing sure it was done.

Make sure you do a compression test to see if anything else was damaged when the plug tip let go.