A few days ago we had a customer asking why his 3500 mile engine he bought from us had a water leak from a spark plug !.
He sent the picture attached and only when we looked closely you could just see the the spark plug was at a very slight angle.
Now curious , I then went further and cut up a Rotor Housing using an industrial band saw and found the the water gallery runs very close up behind the Leading Spark Plug .
As many will know you cant get directly onto the lower plug on the rear rotor on an RX-8 and I had seen people strip the threads before on this one.
This guy had cross threaded the plug on entry, then just animaled it in and cracked the housing :roll: and chances are the plug will snap trying to undo next time.
Moral, of the story is "Make sure you put your Spark Plugs by hand first before fully tightening "!