clancy

Update: replaced plugs and drove for a few days. Drove just fine until it didn't. Started missing badly. Found the same #6 cylinder plug had the tang or ground bent up into the center. I am guessing the previous plug's electrode and center must still be in the cylinder bouncing around on top of the piston and struck the new plug and bent it. I am trying to figure how to get it out of there without disassembling the motor.

I am going to try removing the plug and using a vacuum with with a small hose stuck into the plug hole. Although I am skeptical it will work. Guessing the stuff floating around might be too big to fit into the hose.

Any suggestions? Other than tearing down the motor..

Anyone in the Denver area with one of those micro cameras?

Thanks

tester123

A vacuum may not work IMO because there is little air and if the valves are closed, there won't be any air for vacuum cleaner to 'vacuum'. Even if you get a small hose and that allows air from its sides through the spark plug hole, how would you maneuver it and make sure you got it? I don't know. In theory it should work.
What good will this do other than allow you to make some youtube video... okay, you'll see where it is.... then what?
Try this: Take a small neodymium magnet (not the black ones you find on refrigerator magnets.... some of these now have the "steel" looking neodymium magnets... ), then secure it with duct tape etc. to a metal wire with a bend or a small loop towards the end. Secure the duct tape with a wire-tie above the loop. The idea is to make sure your magnet won't drop or get stuck in there. Lower the wire with magnet and move it around the cylinder slowly and bring it out. This should pick up any metal fragments in there. Spark plugs are not aluminum so, it should work.

That is what I'd do. Others may suggest something better. Your call.

jcman

Clancy I was afraid of that as I've seen it before, a mag tipped flex tool might do the job with the piston all the way down and unfortunately at this point you might consider having the chamber scoped out to see how the valves look but a simple compression test can determine any further diagnosing.

clancy

I like the magnet idea, but am told the center electrode is not magnetic.

My confusion is how the electrode has survived inside the cylinder. I would have thought it would have been broken up bouncing around and getting compressed into the head and/or valves. But it has apparently survived intact enough to have bent the ground tang. I am assuming it may eventually either score the cylinder wall, or get exhausted into a turbo or both.

I've never seen a spark plug center electrode outside of the plug. This is the part that is inside the cylinder. Is it going to be too long to be able to suck up with a vacuum? I am visualizing trying to suck a pencil up a small tube. Is the pencil point going to align with the vacuum nozzle or will the nozzle draw the pencil up along the middle of its length?

clancy

Now that I am thinking about using a vacuum, instead of putting a hose into the cylinder, what if I find a vacuum hose tube that butts up to the spark plug hole around the outside? Thinking that this would allow a larger item to come out of the cylinder if I don't try to shove a tube into the spark plug hole. Then what if I turned the engine over while doing this so the piston moving up and down might help encourage the electrode to get sucked up the vacuum? Also wouldn't the valves opening would give me better suction?

Is there a simple way to temporarily shut off the electric spark to the other cylinders? I don't want the engine to actually start. Also, the fuel? Maybe just take the fuel pump fuse out? If so, which one is it? 2000 A6 2.7 tiptronic.

Thanks

tenspeed

I would use a shop vac and put a piece of nylon stocking as a filter across the snout to catch anything that comes out of the cylinder. Then I would use a piece of 3/8" poly tubing duct taped to the hose and cut the business end at an angle.

Concentrate on the lower side of the piston. If there are any loose parts, they should be down on that side.

jcman

^^^THIS!!^^^

clancy

Well, it has been a year since this issue. Tried the vacuum w/o success. Did not scope it. Just replaced the plug and drove it. It took a few days of driving to clear up the occasional miss due to carbon build up in that cylinder because of the lack of detonation.

It has been a daily driver since, without any issues. Guess the electrode made its ways through the system without damaging anything. Or at least nothing that has shown up in the last 15000 miles or so.

the_duke

Glad it worked out. Thanks for the update too. There are too many threads that never have a conclusion.

jcman

A good mystery should have a end.....whatever the outcome is.