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Discussion Starter #1
So, the title says it all. #5 cylinder was hungry and ingested some or all of the spark plug. Needless to say, the engine runs like cr*p. Borescope shows a pretty beat up piston head. No idea what other damage may exist. Any ideas on value as a donor body?
 

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Discussion Starter #4
Anyone care to chime in on the viability of just repairing the one cylinder and leaving the others stock? Google results suggest possibly putting a sleeve in the offending cylinder and using stock replacement parts to keep everything balanced and even. Thoughts?
 

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If the damage is limited to nicks on the piston head and valve damage, it might be possible to pull that head and have those valves serviced/replaced.

Years ago I was rebuilding the engine of my turbocharged '72 Datsun 510 at my friend's auto repair shop. I took the shop rags off the top of the block, plopped the gasket and head on, tightened it up. After installation back in the engine compartment, Joe fired it up. There was an immediate metallic clatter from the engine, and to my shock Joe just revved it up. Suddenly the noise was gone, and I asked WTH was that??

"Oh, must be that sheet-metal nut from your car that I found on the floor. I put it in one of your cylinders so it wouldn't get lost. Must have gone out through the exhaust valve"!
 

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Depends on how bad the piston is. I would try a compression test to make certain the plug did not get caught in an open valve. If compression is good, put a new spark plug in and drive it till it dies. If the cylinder is bad, a used engine is far cheaper than a sleeve. Without repair, I agree with 4zfed that the car is worth $4-600.
 

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I would check the cyclinder wall with the borescope. If it’s a bit nicked, it may be possible to bore it out, but I don’t think sleeving is an option on the 1.8. Piston sets are about $600, and the block bore shouldn’t be too expensive (if you disassemble). You may just want to go the used engine route.

If the cylinder wall is good, and there’s no hole in the piston, then you can probably get by with just pulling the heads, fixing the valves & seats, and smoothing down any rough spots on the piston.

One unknown is any turbo damage from flying chunks in the exhaust.
 

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What is the mechanism for an engine "eating" a spark plug? Electrode erosion? Something we can prevent with regular spark plug replacement? Pardon my ignorance ... .
 

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Very rare for spark plug to be the cause of failure, suspect detonation or impact from foreign object (valve or seat damage?). If you have compression try a new plug!
 
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