Ignition Coil Bracket 3 R/R

It can be a combination of two things. One you mentioned vibration and all engines have some it’s just has to be mitigated to it’s lowest level. Then you may have too much side torque or stress on the bracket. It should be in a relaxed state as you snug it down.

not uncommon here

Thank you for the quick responses.

I’ll check for side loading or torque. It sounds as if it happens, but not necessarily frequently. 

Cheers!

I’ve seen very few, but I have seen them.