Serpentine belt replacement

I had my serpentine belt replaced 3 months ago because it was starting to shred. Yesterday it broke again The garage said the second time was caused by a problem with the crankshaft pulley. Shouldn’t they have noticed a problem with the crankshaft pulley the first time it was replaced?

Yes, they should have looked for the cause of shredding the first time, but even mechanics make mistakes and overlook things. Or they may have just assumed that the first belt was coming apart due to age.

The problem with the crank pulley may not have been apparent three months ago and may have worsened substantially since then. You don’t give much information about your Cutlass, but if you have the 3.3L engine, you are not alone with the crank pulley issue. It’s a fairly common failure on that engine, but the new, aftermarket version is much less failure-prone.

This could be a pulley alignment issue, there are tools and techniques to check this out. 3.3L? is this a typo? I really can’t remember when the last cutlass came out.

3.3L was offered in the Cutlass Ciera in the early '90s. The OP does not specify the year or whether it’s a Cutlass Ciera or Cutlass Supreme (same as Pontiac Grand Prix). It looked very similar, physically, to the 3.8L and shared a lot of components. For some reason, I saw a lot of balancer failures on the 3.3L, but very few on the 3.8L, which was used in the larger cars. Could have been a completely different balancer.

I’m almost positive that the 3.3 and 3.8 were different pulleys, but I’ve seen the rubber come apart on both of them. Sounds like they are about the throw a rod in both cases.