I don't of any scenario where a "timing jump" could could cause the piston to contact the spark plug as any timing issue would be with respect to the valves and pistons, not spark plugs and pistons.

I'm reading between the lines, but if a valve timing issue is noted, than a much more likely scenario is that the valves and pistons collided, breaking a valve which then proceeded to destroy a spark plug.

Is your car manual or auto? The most frequent cause of an engine jumping time and causing the damage we're talking about here is a botched downshift to too low a gear which overrevs the engine.

- Mark

 

Okay, I reread all your posts to get a clear review of events... The best I can tell is you are saying a piece of the sparkplug broke off and damaged a valve seat and cylinder wall (Do you have a picture verifying the cylinder wall damage?). No pistions hit the valves and no pistons hit the spark plugs. Engine replacement is required because of the cyclinder wall (and possibly rings) damage, plus the valve damage. Is that right?

I would think if the cylinder wall and rings were not damaged, then a simple head repair would fix it (?).

Where I am confused... Did the timing chain ever jump like the mini dealer is claiming? Either before the timing chain replacement or after? (The piston did not hit the spark plug and the timing chain should not have jumped after the replacement - It's all new!)

If it jumped before the timing chain replacement and some kind of oddball piston firing explosion damaged the plug or broke it, the plugs should have been replaced then (Again, the piston did not hit the sparkplug!)

If a plug was dropped while the carbon was cleaned and bent back into position before being reinstalled in a weakened state, that's just bad practice by the party doing the repair, but difficult if not impossible to prove.

For what it is worth, IMHO those plugs should have been replaced when the carbon was cleaned. IIRC spark plugs on JCW's get done at 30K (correct me if I'm wrong) and if I had an MCS that I ran hard, I'd follow that schedule.

What you have against you is that low oil confirmation on your records. Excessive heat can do all kinds of things to engine parts and apparently the S engines run really hot. Although, if the engine was too hot at any point in its' history you should have gotten an engine warning light for that . That's way I like good old fashioned analog guages with warning lights and buzzers (Idiot proof as it can get! That's why they call them idiot lights. )

Still very curious about what your "black box" says about what was happening at the time of the failure??? Oil low? Temp high? No oil pressure? To bad you weren't the one driving...

 

I would be VERY reluctant to hand over any money to have it repaired until I knew exactly what the problem is. There is no way a new cylinder head is going to cost as much as installing a brand new motor. Sounds like the shop is trying to get some extra money out of you.

Call around, get a second opinion.

 

Too late, it seems the OP dude already swapped the engine. I guess the stealer keeps the old engine as a core item. Pity, it would be interesting to tear that thing down. I don't know if I'd spend 6-8K on a MINI with 60,000 miles. Probably would have found an indy shop willing to work into the repair rather than jump to a swap. Failing that, I'd have parted the thing out and gone in another direction before going back to a stealer with that much cash. Damn shame.

 

Guess I didn't read enough of the posts.......

WOW....I can't believe someone would pay that kind of money without getting another opinion, and doing some more research. Could have been a $1000 (or less) fix

 

Hmmm... I guess Satang has dropped it now that the engine has been replaced. I'm now wondering if the prior low oil issue is at the route cause, thus adding to the timing chain failure because of excessive heat and lack of timing chain tension due to lack of oil/oil pressure???

If they found cylinder wall danage when inspected, I may in fact be heat scoring from when the oil was low, damaging the rings and spark plug electrode(?). If the rings were gone by the time he loaned the car out for a long trip, it would burn oil rapidly and once again go low, heat up and come close to seizing when the engine light was finally noticed. If the CPU says oil was low at the point of damage, that "might" explain what the dealer is telling him in incorrect words. Of course that is all once again just speculation on my part...

At least he's back on the road and hopefully enjoying his mini with a brand new engine!

 

I think BBB.org would have helped here. At least they would have asked MINI usa to contact NGK formally. They always help. They helped me with unnecessary dealer warranty stuff on my older Altima. I would suggest this, but I think its too late now.