Sorry to hear about the issue. My shop has a car that had the exact same problem. Issue with the plug resulting in piston damage and rebuild.

 

You might want to look into what the warranty laws are in your state. Lots of products have warranty disclaimers printed on the packaging, but in some states these are of no legal significance. And while I cannot remember ever closely looking at a spark plug box, I do not recall ever seeing a warranty disclaimer or limitation of liability language on a spark plug box. Many states have implied warranties to the effect that the product is of good quality, free of defects, and suitable for its intended use. These implied warranties often derive from the Uniform Commercial Code, which is, as the name implies, pretty uniform from state to state.

There is also the issue of the damages recoverable if a warranty is breached, that is, under local law is just the plug itself covered, or the engine repair expenses resulting from the faulty plug.

Given the magnitude of the repair costs, I would be all over the plug manufacturer under California law. But I don't know NC law and cannot advise you on that.

Good luck

 

I'm curious why nobody went looking for the missing ceramic insulator and electrode after the first diagnosis? Ceramic doesn't burn up (a carbon electrode might)...

Or perhaps I'm missing something?

 

That's what I asked, too, few posts ago.

 

Warranty is a non-starter, ceramic probably broke from the new plug(s) being dropped at some point (I would replace all as they normally come in a box of 6 I think). To prove warranty, you could need to prove a manufacturing defect, the plug and ceramic will have taken a battering so no likely and you will be throwing good money after bad. And after all you have been through just be glad of another tail to tell while sitting on your new sofa

If you can afford it, replace all the valve guides, you will have taken care of the main wear item on the engine.

Could drop in some 4.0 pistons and barrels, would only cost you a kitchen or new bath room on your previous experience lol!

 

When Karl found the plug so damaged that you can spin the ceramic insulator with your finger, probably about to literally blow it clean off, and the center metal electrode gone, along with most of the inner insulator, he scoped the cylinder and found it looking good, so replaced all plugs and coils, and away I went, to have the problem occur a hundred miles on, when I once again ran it up to about 7K rpm.

No codes came up this time, so he pulled the cams and actuator out, the followers all looked fine, so decided to go further, and sure enough, the tiny electrode was still in the cylinder, and had not gone out via an exhaust valve as originally thought. The tiny electrode was just not able to be seen with his bore scope. So with a new piston and liner, and new valves and seats, it should be fine. The inner surface of the head actually is fine. As for warranty on the plug, I will see what I can do, but am afraid like mentioned above, the plug company can claim it was damaged after being boxed and shipped. All the plugs were changed after the first episode, so if it is a manufacturing defect in that lot of plugs, they are all out of the motor. I suspect that even the several thousand revs when I was coasting after the initial misfire would have damaged the vlave seats that it would have been necessary to pull the head to repair the valve and seat. Interesting that even with a hundred miles with the electrode in the bore, the compression and lead down are still fine.

But in a sense, if the teardown had not found found a definite cause, just some mysterious unknown, potentially recurring problem, I would always had some worry that the problem could recur and would have worried about trips and just driving the car. But now, with this absolutely fixable problem, our GT3 will be as good and reliable as it was previously.

Hard to be reassured that an expensive repair is because of such a cheap part, but just my bad luck. I happens. Just to add this unusual symptom to the collective experience of other forum members.

All the best...

 

It's reassuring to know that the problem is not the engine/block itself.

 

I'm sitting here in disbelief, and stunned by your dilemma. Your misfortune sounds like something that might happen to me....But what I am really concerned about is the "root cause analysis " which created this problem.


I'll chime in with this: the ceramic of the spark plug is very hard and brittle which in turn makes the ceramic crack from basically any form of hard impact; being dropped or knocked off a work bench onto hard concrete surface. Unfortunately, I'll bet this hard impact of the spark plug hit the ground just right which is like a one in a million chance, created very fine cracks. Now apply heat, pressure, firing of cylinder and a little time....


I would discretely have a discussion with shop and technician that might have performed any associated work recently. This is just something we will have to eat. I'm in Charlotte all the time. Please pass along the name of the shop so we can all avoid the same scenario if you might think this is your root cause. Regards

 

I guess I'll play devils advocate here.

If I read this right, the plug was severely damaged and replaced with another new one, (set), Engine had compression and leak down test and everything was ok. Borescoped the engine.

If there is no leak or hole then the compression and leak down test would show good. Even with a bad plug. Then it can be said the Valve and Valve seat must have been ok too. If the piston was not damaged at this point, and is now damaged, the part of the plug was still in the cylinder and not seen with the borescope.

Regardless of plug brand etc, I think you were given the green light to go when in fact the missing part(s) were not found. You now face the cost of repair because of this. The part cannot leave the engine or its parts, It was either in the Intake manifold, trapped in the exhaust or still inside the cylinder. From your post, it doesn't say the intake or exhaust were searched for the missing part. To put an expensive engine at risk without knowing for sure the part was found was negligent in my opinion. You paid the price for this. Regardless of your predicament, travel plans etc, the person inspecting the engine has to make the hard choice and stop you from driving without checking deeper.

We expect this from our medical doctors, why not the doctor of the engine.

 

I want to be sure that there is no lingering suspicion of Aaron at Zuffenhaus, who dropped my engine to do the weld on the pipes, and other preventive maintenance about 1100 or so miles before the plug failed. He carefully puts the ingoing plugs in a wooden block so they don't roll around on his work bench, and then handled them to lightly wipe a little antiseize on the threads. Then carefully install them.

I don't know how spark plugs are made, but i have a hunch that from the time the components are loaded into the manufacturing machine, no hands touch them, even putting them into their little boxes. But somewhere in the manufacturing process, something went awry, and it failed.

I have accepted the fact that this is just what sometimes happens, when countless millions of spark plugs are made and shipped.

As for what happened to the missing plug parts, I trust that Karl did what he could to determine the problem was a failed plug, and get it running again with new plugs and coils. I am OK with what both shops did and are doing with my car's engine. But no more Bosch plugs in any of my cars. Beru only for the Porsche. There is an ongoing inquiry to the supplier of the plugs for information as to any history of failed Bosch plugs of my car's model.

Interesting that even with damaged seats and valves in #3, the compression and leak down is STILL within spec.

all the best....

 

Nam Vet,

I mean no disrespect to anyone here, but maybe some info for others to know. If the plug failed after 1000 miles, I think you had an issue with detonation after some lower octane fuel. maybe the mapping is any is on the limit.

I would not rule out Bosch plugs or any other plug. The cause I would bet is not the plug.

This may sound harsh but the damage to your engine is the fault of the last person to touch it. If it looked good before he gave the car back to you, (borescoped) he or the business are at fault. Any good mechanic knows that if you remove something from inside the engine and its broken with missing pieces, find and establish where the missing parts are.

Nothing can get out of these engines. It could be in the Intake and the filter box if it got sucked up with vacuum, inside the Cylinder or in the Exhaust before the cat. There is no escape route. To find the plug broken and not find the other parts, and then send you on your way was negligent. Your engine was put at risk and subsequent damage by this action.

At no time should any engine be put to risk by any in actions. The cost of disassembling the engine is upon you now along with parts repair and replacement. Before you only had to disassemble the engine and remove the parts. Hopefully before the engine was disassembled the part may have been found in the Intake manifold or exhaust. If not the engine gets disassembled and the broken parts removed before any further damage results. In your case several prudent steps were overlooked which resulted in your present expenses.

One hopes the shop steps up and takes care of this for you. It was their mistake not yours. Hopefully others will remember this if the same happens to them.

 

I would guess the damage was already done. As the owner you decide if you want to spend $10k on a strip down or take a gamble on the new plug remedying the situation. Most of us have been in this dilemma before.

I would move on, the fate was seal along time ago and I don't think Nam Vet needs more stress in his life.

 

I feel that way Ur20V. In about two months I will likely find out if my prostate cancer, unfortunately a high grade disease, is metastatic, and what chemo choices I will have. As a mostly retired physician, I am a realist about potentially lethal illnesses, and just want to get our GT3 back on the road. It is a thousand miles away, and when it is done, I will fly out and take the long, winding road back to SC. As for the $ spent, I tend not to think about "what if's" both for my hobbies and my own health. Besides, my other interest and hobby is making and shooting ammunition. I reload for 14 different calibers, and a few days ago was accepted into another gun club, this one has ranges out to 800 meters, so when I get a good scope on my new 257 Weatherby, I will see what kind of ammunition i can make for this rifle too. Started on some 30 30 Winchester ammo yesterday for my son's new '94 Win lever gun. Gave his wife a rare, tuned by Cylinder and Slide early '70's Colt Combat Commander in 9mm last week, just perfect for her smaller hands. I load light rounds for her, as she is still recoil sensitive.

And my wife's new furniture looks very nice in our home.

I am good to go, so as always, all the best to each of you.....

 

You're a wise man Hal! I look forward to hearing about your drive.

(and I'm glad you like that new furniture )

 

YOLO my friend, enjoy in (hopefully) good health