93 Subaru Loose Spark Plugs

[Scott White]

I have a 93 Subaru legacy that has a spark plug problem. The drivers side
front spark plug always comes loose. I torque it tight and 2-3 months later
it is loose. Any way to fix it?

 

[Edward Hayes]

I have seen Champion plugs where the threads were undersize. Put in new NGK
plugs with the crush washer and torque to 15 foot/pounds. You should have no
problem UNLESS you over torqued previously and distorted the threads. eddie