Dodge: Ticking in motor, dodge dealership, dodge avenger

Question
I own a 1999 Dodge Avenger. For about 3months or more it has been this ticking noise in the motor. I took it to the Dodge dealership and they said it was a lifter, so they put something in it to stop it but they said it would take time. It seems to me though it has gotten worse. It sounds louder than what it was and sounds like it is a knocking noise but I know nothing about cars. So if you can help I would really appreciate it.
Thanks!

Answer
Does the engine do it all the time or just while under a load(air conditioner on).How many miles are on the engine?A lifter will cause a ticking noise,and they do make an additive to put in engines to stop it but it won't stop it forever.It's just a quick halfway fix.The reason i asked these questions is because low grade gas will also cause a clattering sound but this usually happens while driving,if it's doing it at an idle,it's probably a lifter ticking.