I noticed my AC had stopped working on my way back from an out of town trip. Didn't think a whole lot of it, maybe it needed another charge, but I didn't look into it that night after six hours of driving.
The next day I hear a weird whap whap whap
noise when I started the car. Didn't check under the hood until I got to work, and saw the AC belt had partially shredded and wedged itself behind the AC compressor pulley. I cut the belt off and was able to drive the car home.
It wasn't until I got home last night that I looked more closely, and realized the AC belt was the symptom and not the cause. It looks like my crank pulley has started to delaminate, and that outer grooved ring section has started to back off the inner hub. The outer section had worked its way about 1/4" into my timing belt cover, which shredded the AC belt. In the pics below you can see the crank pulley-shaped hole eaten into the TB cover, and on the overhead view you can really see how the pulley is out of alignment with the rest of the accessory pulleys.
Good thing, too, or I might not have investigated properly before it worked its way into the timing belt itself. Clearly this failure mode could have been catastrophic, especially had it occurred two days ago while I was out of town on the Interstate.
What do you guys think? Am I on the right track as far as the crank pulley delaminating being the root cause? The crank snout, key, and front main seal in the pic below all look good, which seems to eliminate some of the scarier possibilities, like crank walk.
Thanks for looking. All suggestions, comments and commiseration are welcome!
PS, car specs:
2000 Outback Wagon, 2.5L SOHC, AT, 164k miles