Quote Originally Posted by baludoy View Post
When changing your ride's serpentine belt, is it a must to replace the tensioner too?
IMO, it's not required as long as it's not making any fuss.... no bearing noises, excessive play, and especially if the pulley wheel condition is still good, etc... it can stay. If the pulley wheel is worn down and has ridges, it might eat up the new belt. Otherwise, they are pretty much accessible and can be replaced at any time.

It's when replacing the timing belt or timing chain is when you should replace many of the other timing components... guides, tensioner, sprockets, and sometimes including the water pump if it's in there and/or driven by the timing belt or chain.