ok so my cousin borrowed my car... came back and it was running funny... like my car was dieing so i checked under the hood didnt see nothing till i tilt my head looking at a spark plug wire hanging... i reached for it and ZAPP!! i didnt know i should of turned the car off but there was sorta blue powder or residue on it. any idea how the wire could of blown off like that? its the end where the wire hooks into the distributor. i look into it and the metal piece is just gone.

 

It probably needed new wires like 30k ago (exaggerating). Sounds like wear and tear, just should have replaced before this happened.

 

yep, mine use to pop off all the time, replaced em and worked just fine

 

Loose electrical contacts will destroy themselves pretty quickly, arcing causes all sorts of fretting and erosion.

 

how often are you supposed to change them??

 

Give them a visual inspection periodically for corrosion, tears, and burnt contacts. Stores or dealerships will sometimes give you a certain mileage, and you could even check your owner's manual. It only takes a minute, tops, to pull off the the wires and check them. So why not every oil change or just whenever your fucking around under the hood.