accessory belt still very loose after replacing alternator

[tttomttt]

I seem to remember that there is a belt for hydraulic tensioner and a different belt for mechanical tensioner.
I apologize is this was mentioned already as I did not read the all the posts.
Glad you were able to fix the issue.

[jdstrickland]

Originally Posted by oldskewel

I've got a different engine (M54), but assuming you bought the right belt, I'd double check the routing around all the pulleys. Somtimes there are different ways that it will route, and one is right and one is not right.

If you hold the new and old belts up to each other and measure them, and they are the same, then you must have the new belt routed improperly. The old belt cannot stretch so far as to be loose. It can be shredded, and it can be cracked with age, but it cannot be stretched. It could be stretched something less than 1/4 inch, but it cannot be stretched so far as to not fit. A new belt will be marginally smaller than the old belt, but if it's the same size then it will work. If the new belt is larger, then it's the wrong one.