How does a fan blade slicing through the radiator sound?? If they say to replace it, I would do it.
I have seen the fuel pump on my old Corvair leak fuel onto the harmonic balancer and the rubber got all messed up. I bought a car that wouldn't run, acted like the timing was off but the mark was exactly where it was supposed to be. Turned out the outside ring on the harmonic balancer had moved a bit and threw the timing mark off. I re-timed it by ear and drove the car home after I bought it. I didn't know the harmonic balancer could move like that. After that, I seemed to find a lot of them that were all swelled up or cracked. Not that uncommon