Hello all! I'm going to be as vague as possible, to protect myself and everyone involved and to not out myself, as I haven't decided how I'm going to approach this issue yet. I took my car into JLR for a single-cylinder misfire issue. Diagnosed injector as bad/ stuck open, replaced both injector and spark plug. A few months go by, and same misfire in the same cylinder. They find the spark plug crushed and the injector uplugged. The replaced the spark plug and plugged back in the injector. A few days go by and same misfire AGAIN. They found another spark plug crushed, and borescoped the cylinder, to discover my piston has a chip in it now. They never mentioned the spark plug as crushed, or even bad the first time I brought it in, just specifically stated the injector had electrically failed. OEM new engine block is $25000 with labor. Looked into used cylinder head and piston for the correct aspiration method which would save me a good $10-12k.

I'm wondering if anyone had any input as to what I should do? Dealer wont budge and states the injector being unplugged wouldn't have done anything, and I don't think this problem occurred out of the blue.

 

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Sorry that's a new one on the forum??
Never had a piston chip reported. I don't understand how a chipped piston will crush spark plugs? That indicates something is loose in the combustion chamber and bouncing around.
If so they should be able to fish it out and inspect it.


You did not say what year/model car you have or the mileage so I am not sure if your under warranty or not?
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Well... this OP is a couple of years old now, don't know why it was revived other than the novelty of it.
True, it would be odd for a chipped piston(?) to damage a spark plug, but consider instead what would happen if the spark plug itself was the wrong one. What if it was too long. What would you think might happen to the piston dome if the spark plug is much longer than spec'd?
Otherwise, if there were anything loose bouncing around in the combustion chamber, it would be noticed pretty quick and cause a lot more damage than a crushed spark plug.

 

it was revived because my device had an issue and somehow I responded to this thread and one I intended at the same time, thus , the delete above.

 

As for the piston chip, My guess would be that the spark plug was over torqued breaking the porcelain insulator. In the alternative the plug was dropped cracking the insulator and installed anyway. If the insulator or a piece of it came loose, it would shot peen the piston top and possibly go out the exhaust port. I actually saw this on an 87 XJ6. A dead plug when pulled was missing some of the insulator. The car was high mileage almost 200K. A compression test was performed and was within limits. No teardown was performed.

 

We will probably never know what happened, as the OP appears to be long gone from this Forum. He had a 2011 XJ.