[svxistentialist]

Keith's approach is good as I see it.

The pulley is mechanical, and will have a certain failure rate built into it, like all things mechanical. The longer the number of hours it has been running, the closer the failure point will get. A car that has done 160K miles has had its pulleys whizzing for a long number of hours.

So when you add to that the fact that the engine is over 15 years old, it would seem to indicate the idlers need replacement if the car has run more than 100K.

Sensible? No?

Joe