Tips on removing plug insulator pieces from cylinder?

Never had this happen before. I was removing the plugs from my '89 Cressida when I noticed the ceramic electrode insulator on one was broken. I looked in the cylinder with a boroscope and sure enough, the missing piece is sitting on top of the piston.

Obviously, I need to get that piece out but so far have been unsuccessful fishing it out with a 4-finger grabber. It's large enough that I imagine the grabber could hold it, but it's kind of off to the side (couldn't be conveniently right in the middle, hell no) and of course I'm trying to do the grab blind. Tried a shop vac with a piece of vacuum hose sealed off with duct tape to the larger wand and snaking it down there to suck it out, but so far that hasn't worked. I tried slicing the end of the hose at an angle to increase the opening, but no go so far.

Any ideas? I'm not sure what I did to cause it to break off like that just unscrewing the plug, though it was a bit stubborn coming out.

Thanks for all input.

Reply to
Doc
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I think you are on the right track with a vacuum hose. Try a smaller diameter hose to both give you more wiggle room in the plug hole as well as increase the suction.

Reply to
John S.

The vacuum hose is really smart... I like that one a lot. How about bubble gum on the end of a long screwdriver?

--scott

Reply to
Scott Dorsey

If there's room with the boroscope, I'd get a piece of wire and see if you can watch the wire end and manuver the piece until it's in the center and then hope that you can get the grabber on it.

It would seem that the vacuum hose idea doesn't have enough air flow to get the piece to move over so I think that might be a lost cause. The only way that would work is if you could get the hose to touch the piece. I would imagine you should be able to get some kind of tubing that you could bend a little bit to get it closer to the part.

If you could get it to flow enough air, you could try opening the intake or exhaust valve and sealing the shop vac to the cylinder hole and see if you could suck it out that way.. Make sure the piston is as close to the spark plug hole as possible. I think the vacuum hose constricts the air flow too much to be effective.

I assume this is where the spark plug holes are on top of the engine, not on the side? If it were on the side, you might try washing the piece out with water and then sucking the remaining water out using the shop-vac method.

Reply to
Bruce Chang

vacume will work providing the vavles are closed

Reply to
tudysmuck

blutac or chewing gum on a bit of welding rod

Reply to
mrcheerful

uh.. not the way I've described it. You'll just have a vacuum in the cylinder and the piece won't go anywhere.

Reply to
Bruce Chang

Got a hot melt glue gun? Get a straw and fill the end with hot melt. let it get a little tacky and then stick it down the hole on top of the insulator so a little of it will run out of the straw and bond to insulator. Let it set up for a while then try to pull it out with the straw.

Bob

Reply to
Bob Urz

A last choice, workable if messy way is a)rotate the engine to about 30 deg BTDC for the affected cylinder

b) pour 10-15cc of oil into the cylinder, swish it around with a piece of L shaped wire. and crank the engine over with all the plugs out. The krud will usually be ejected at speed out of the plug hole. You might want to cover the engine and maybe put something over the hole to catch the oil.

Stewart DIBBS

Reply to
Stewart DIBBS

I wouldn't do this. Cranking the engine with debris in a cylinder is call for potential damage.

Reply to
mst

You have plenty of good responses regarding insulator removal. Now, I'm going to guess this happened to cylinder #6? If I'm wrong, stop reading here.

If correct, I suggest that you have a small head gasket leak around cyl

6 on your 7M-GE. Slow headgasket death around #6 is fairly common on that engine. As a result, the relatively cool blast of finely atomized coolant from a very small leak cracks the porcelin of that cylinder's plug.

By now the ceramic may have bounced around in the cylinder and pockmarked the piston and combustion chamber -- unless it has cracked off recently during an engine-off cooldown. The resulting marks are harmless. The ceramic is pretty tough, but the fact that you can still see a large portion of it leads me to believe this happened recently, as it eventually gets ground up into many pieces.

The head gasket will get worse. If this is your problem (why would you read this far down if it wasn't?) then it's time for a new gasket and head resurface if the typical 7M-GE ring and corrosion marks are deep enough to warrant such action.

Toyota MDT in MO

Reply to
Comboverfish

I read it for informational purposes and curiosity. This is actually on cyl

  1. The engine was rebuilt by a pro shop with a good rep about 15-20k miles ago, so I'd say while such a thing as you outlined while not impossible, it's not at the top of the list. Still, I wonder why the ceramic cracked. My reason for wanting to change the wires, plugs, cap and rotor is that the engine suddenly developed a miss.

When I rebuilt the engine, I put in new plugs and I think wires, not sure, but definitely reused the old cap and rotor since I was just trying to get it going and at the time scraping/sanding the contact points on the cap and sanding the rotor a bit made it run fine but they've further degraded to the point where I'm sure they're not getting good spark through.

Reply to
Doc

And btw, thanks for all input.

Reply to
Doc

As I said, its a LAST choice, short of taking the head off.

I did this some years back to remove a piece of broken ring on my rally car during an event. The engine was already toast so a little bit more potential damage was not an issue.

Stewart DIBBS

Reply to
Stewart DIBBS

The missing ceramic insulator on a spark plug will cause a hard misfire in it's cylinder.

Hopefully the broken insulator was just a fluke, but for peace of mind you should monitor coolant usage. It's always possible that there's a pinhole leak in cyl #5 gasket area, though cyl #6 is the common failure point.

Toyota MDT in MO

Reply to
Comboverfish

Shortly after I got a car tuned up it started missing. They found out that a fairly good-sized chunk of the plug's ceramic insulator had fallen off. I asked them about damage but they sait it would have instantly shattered into dust and been blown out the exhaust. Now that you've posted about using the boroscope, I wonder if I didn't have a chunk of ceramic bouncing around in the cylinder for a while after that.

On the plus side, maybe it's a good thing, to create turbulence and mix the fuel and air better, like the marble inside a spray paint can mixes the pigment with the solevent. Sorry, I was kidding there.

Ok, would it be feasable to idle the engine for a few minutes without a plug in that cylinder? It's almost certain to bounce that piece right out of the plug hole, unless it's at a sharp angle.

Reply to
Ernie Sty

I had a NGK plug sitting in a cylinder that had a miss. I ended up doing much of what you are doing to correct it. The plug's insulator actually slid down the center conductor and touched the fingered (bent) adjustable contact of the plug when held in the "insulator down" position.

When I viewed the plug with the "insulator up" as one normally does when inspecting the plug, the insulator would slide back down into the plug as though it were a normal plug. Just when it goes into the engine (down pointing) did it cause the engine miss.

That was a fun plug! I suspect it cracked when they crimped the shell of the plug to seal it.

B~

Reply to
B. Peg

I've caught a couple of Nippon Denso plugs with that issue. Just like you said, it can be hard to spot if the insulator slides back into position during inspection.

Toyota MDT in MO

Reply to
Comboverfish

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