A few months ago my car had been misfiring. It turned out to be the ignition coil, once I got that replaced the car seemed to run fine, but, a few months later, while I was driving my car began backfiring, I pulled over and noticed that a sparkplug was loose, I replaced it, but the next day another plug came out (different cylinder). After this, I replaced all plugs making them quite tight, about two weeks after, I checked all the plugs and they seemed to be just as tight, so I forgot about it but tonight while driving, about 3 or 4 months later another plug came out, it is the same plug that came out first last time, however this time I could not get the plug to sit.
So my questions are�.
Does anyone know what would make the plugs unscrew themselves?
And
If the plug cannot get seated, does this mean it is stripped, if so how can it be rethreaded?
Thank you for any response!
