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Discussion Starter · #1 ·
Hey everyone,

I have a 2000 DOHC engine with 185K miles that was starting to misfire. Replaced the coil, plug wires, and plugs. On the #1 cylinder, the plug came out but cracked a bit and I had a piece of porcelain or electrode that I think fell in to the cylinder.

I used a shop vac and straw to vacuum as much of the debris as I could out.I got everything visible out, but when I put all the plugs in, and crank it, it has a knock that was never there before. I only let it turn a little bit, because I don't want to ruin the valve or cylinder. I've tried to crank it a few times to cycle through and see if the debris reappears so I can remove it, but no luck.

Any ideas to remove the debris without removing the whole head?

I have a driveway to work and it is going to be cold soon.

Am I screwed?

Thanks for all your help.
 

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DTC P0606
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Cranking it a "few times to cycle through" was a mistake. An engine borescope should have been used to see if the cylinder was truly debris-free. Can you rent or borrow one? Might be too late.
Turn the engine over by hand in future; technique varies depending on type of transmission. Don't use the starter.
 

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Discussion Starter · #3 ·
I thought it was debris free and realize I should have done it by hand now. I don't have access to a borescope or ability to rent one.

I pulled out a few good sized pieces and I thought all of the porcelain. The only thing I am worried about is the electrode, which is bad.

I haven't done that in depth engine work for about 20 years, so I don't really want to have to pull the head and cylinder to clean it out. I've read lots of people have let it run a bit and the debris has been expelled out the exhaust, but that seems unlikely if it is the electrode and not just porcelain.

So what are the options? And how hard is it to pull the head and cylinder on this engine?

Thanks for all your help...
 

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DTC P0606
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Just how badly did this spark plug disintegrate upon removal? Do you have any pics of the plug? The center electrode snapping off would be unusual. Porcelain is very hard and can do as much damage as metal fragments.

The only trouble with "running it a bit" to expel debris is that any debris has to make it past the rapidly opening and closing exhaust valves and seat and that seldom ends well. That's if the reciprocating piston doesn't impale the debris into the surrounding metal of the combustion chamber first.

Get the affected cylinder up to top dead center (to minimize the combustion chamber volume) and use your vacuuming technique once again. Other things you might try putting gently down the plug hole: A blob of grease on the end of a stout wire or a magnetic pickup tool of some sort. Peer down the plug hole with a light and see if there is any noticeable scarring on the piston top.

If you think the cylinder is clear, only a compression test will tell if there is any lasting damage.
 

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I've seen this one before - timing was off, exhaust valves broke and hit the plugs on all cylinders. When we removed the head, the cylinders were littered with ceramic fragments but none of the metal electrodes came off the plugs. I also remember noticing how the fragments moved to the outer edge of the pistons but the cylinder walls were intact. I'm saying this because you might not be reaching far enough across the piston surface with your vacuum method.

Try using some tubing that is flexible enough to bend and reach the cylinder edge and put the piston in TDC on the compression stroke (valves closed) so you avoid sucking in any debris already sitting in the exhaust manifold. If you decide to crank it, remove the plug from the #1 cylinder, disconnect the coil pack and the fuel pump and see if any more debris comes out flying from the plug hole (always keep a safe distance !).

Hope you are as lucky as we were. Cheers
 

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I've seen this one before - timing was off, exhaust valves broke and hit the plugs on all cylinders. When we removed the head, the cylinders were littered with ceramic fragments but none of the metal electrodes came off the plugs. I also remember noticing how the fragments moved to the outer edge of the pistons but the cylinder walls were intact. I'm saying this because you might not be reaching far enough across the piston surface with your vacuum method.





Try using some tubing that is flexible enough to bend and reach the cylinder edge and put the piston in TDC on the compression stroke (valves closed) so you avoid sucking in any debris already sitting in the exhaust manifold. If you decide to crank it, remove the plug from the #1 cylinder, disconnect the coil pack and the fuel pump and see if any more debris comes out flying from the plug hole (always keep a safe distance !).





Hope you are as lucky as we were. Cheers


Zetec is a non-interference engine...
 

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IMHO the only way to see any loose crud is with the piston at the bottom of the stroke.

Can't see toward the edges when it's at the top, or reach around corners into that small space.
 

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@Mandroid - I'm not trying to be rude. Just pointing out that what you described is NOT his case

Not a problem - never thought you're being rude :)

How it happened in our case is irrelevant to bczippy's problem - it's just a little background of how the plugs ended up in a similar situation to his. The significant point of my post is what I observed i.e. the scattering of the fragments to the outer edges of the piston, which could be why his vacuum method was failing.

Cheers
 

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Spark plugs and glow plugs (on diesel) are two things that scare the hell out of me - cheap but very vulnerable especially because they're exposed to intense heat and numerous expansion and contraction cycles. Manufacturing defects and damage during shipment are also a concern. The engine might be running too hot or there might have been rough handling during installation. Hard to tell hence why I usually change mine every 50K - they're cheap and easy to replace (well, they should be...).

One question that I could never find an answer for is this - could ceramic fragments from a plug cause serious damage to an engine or are we somehow overstating the consequences ? I personally never seen it but I'm not a professional mechanic.
 

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It's got 185k miles, I wouldn't sweat it too much.

Since the piston has gone up/down already, big chunks would have already been smashed into the head or piston. Any pieces small enough to slip between the piston and bore already did so.

I would rotate it so the exhaust valve is open, then blow it out through the plug hole with compressed air.

That motor is already 3/4 of the way to needing a bore/hone job, if you accelerated that last bit of wear, so be it.

I would be more concerned with why the working end of the spark became damaged.
 

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elsolo - Any pieces small enough to slip between the piston and bore already did so.

That seems to imply that an oil and filter change are also in order.
 

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I agree with Elsolo. My cuz and I had junker 350 for a derby car that we were running on a cradle, and at some point someone had dropped some sort of BB down the carb while the motor sat, on first start up all it did was rattle around in the cylinder for a a few mins then it just spit it out the exhaust(at a quite violent speed i might note) He needed to rebuild the motor to begin with so he tore it down and it didn't appear to cause any issues bc we couldn't tell which cylinder it was in.
 

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185k miles doesn't seem like much...but then, I'm just a few shy of 300k and my Zetec has never seen a rebuild, fortunately. Still runs great, btw, knock on wood.

I keep some small plastic tubing handy along with a small funnel. A bit of duct tape onto my shop vac turns it into a very effective tool for picking up tiny bits of junk in small areas, like spark plug bits from plug holes. Also good for picking up that small bolt that you dropped and can see but can't reach, and the magnetic pick-up tool sticks to everything else but the bolt.
 

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Rotate engine as to close the valves and a couple quick blast from an air hose will probably blow the remaining debris clear out the plug hole and or keep using the shop vac method.
 

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elsolo - Any pieces small enough to slip between the piston and bore already did so.

That seems to imply that an oil and filter change are also in order.
There is a gap between the piston and bore, but to get to the oil it needs to squeeze past the rings. That is a 5-10 micron particle, you won't see those.

If you aren't gonna tear it down completely to clean it out 100% (and I wouldn't), blow out whatever will and stop worrying about the possibility of debris you left in there.

How did the working end of the plug break, that is the primary concern I have.
 
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