What are the trouble sign on a timing belt that is nearing the end of its life? Should you look at thickness, tensionor for center strip to appear? Also is there any way to diagnose the lifein a water pump?

Many times it it the TB tensioner that fails so it's good just to replace the tb at the recommended interval. my tb looked fine but my tensioner was well on the way out...

waterpump- if you're doing the tb, do the pump. it's cheap and easy to get to at the same time. all your other belts and other stuff which others can tell you or search for.

most importantly when it comes to your timing belt, look at the mileage on your vehicle... people all have different opinions about when they should be changed but generally its from 60k up.....

I have the same issue if the new A4 1.8T I bought. Through the grace of God and now I want to make sure about changing the belt. The mileage is at 69,000.