pretty much just look at them. If they look old/cracked, and or when you rev the engine a little and you can see it moving, it may be time for them to be replaced. Not neccesarily though, only if the rocking is excessive.
ATLANTA DA-Squad member #26...[{Home.BASE.Racing}] •R.I.P. LsVtec DB1....hello b20v EF...!•