Quote Originally Posted by Tobert
It could be valve adjustment. Mine taps like crazy, especially on lighter weight oils.
I was just throwing out ideas with the electrical snapping idea. I guess I had just assumed that the 3.5L VX motor used hydraulic lifters, but I see from the cd manual that a solid lifter bucket/shim type adjustment is used, so valve adjustment could very well be the cause.

How many miles on the engine? VX valve adjustment intervals are every 60k miles.