97 pontiac grandprix pieces of junk?



i own a 97 pontiac grandprix gt 3.8 and i have replaced the belt tensioner pulley 3 times in past 3 years and each time with a brand new from auto zone assembly and had a proffesional install it and anythime my belt gets wet or i drive thru a pretty decent size puddle the serpetine belt just comes right of… my ? is was it assembled correctly or have i just become a 1-1000000 luck to get 3 posssbile manufactor defects assemblies and/or is a prob with others or am i the only one incountering this?


i also noticed each time that the the actual pully on the assembly is about 1-2 lines( lines on belt) over to the left and not exactly inline with the rest of the assembly or serpitine belt so i know that this cannot be helping the situation either!!!