[cnn]

Just google "honda spark plug blew" and you will tons of threads on this topic.

However, I am not certain what causes it. I am just curious what the ROOT CAUSE is:

1. Was spark plug not installed properly (loose at factory) and works its way out?

2. Or is the aluminum head thread weakens with time and the spark plug comes out together with the threads?

Does anyone know the ROOT CAUSE?

 

[cnn]

From what the pros tell me: Spark Plug blowing out of the hole is usually a result of loose torque (not tightened enough).
With time, the spark plug works its way out and kaboooom.

If you decide to fix this, research Helicoil (basically a spring) vs Timesert (a full insert).

Most pros recommend Timesert.

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You may want to visit this thread FYI. Also, see the attached pic. Honda V6 cylinder head has some12 threads, not like some other makers engine with only 4 threads ---> spark plug blowing out.

So in the case of Honda V6, you can see the spark plug (which has about 14 threads) is fully seated in the thread. So to have the spark plug blowing out, my guess is a spark plug loose to start with.

DIY: 2007 Honda Odyssey Spark Plug @ 40K miles
http://www.odyclub.com/forums/showthread.php?s=&threadid=132134