any ideas on what might cause repeated coil failures? I am not a great
mechanic, but want to try and square this away b4 my son gets back
from Iraq for the last time.
I have a tool to check each coil to isolate and replace, but do not
understand why they keep failing?

Thanks for any advise in advance

 

An open plug wire or a excessively large plug gap can stress a coil out because it allows the voltage to exceed design limits before it can discharge through the gap. I am not saying that this is your problem, but you must also consider that age gets to be a factor, use of a CID box with standard type coils can cause problems, and if your engine uses multiple coils the chance of failure increases proportionally.

 

Could also be the Ignition Control Module under it as well. The terminal plugs in on the back side, so you never really see any wiring back there. As above stated, check your plugs for gapping issues. I've been having trouble since I replaced my plug wires with it burning through off the EGR valve and causing misfires. Check all your wires to make sure there are no breaks. Best way is to remove a wire at a time, and roll them up tight so you can see any breaks in the shield.

 

Most of the time it's because of an open plug wire...

 

In addition to what has been said -- heat, but more likely other things.