I'm about to go in for my 90k mile service, and the dealer wants to replace the water pump and timing belt as indicated by Toyota's service schedule. I'm curious what the experts say -- is the preemptive replacement worthwhile? I don't want to run an unnecessary risk of failure, but I don't want to drop a grand on replacing good parts, either. Is there any reliable indicator of whether they need to replaced?

I've had a rattling/light grinding noise when accelerating hard for a few months, and the past few days the engine has been a little loud, as if there's a break in the muffler or something. The car still rides and accelerates just fine, just with a bit of noise. This makes me want to bring it for service; I'm not sure that either is related to the maintenance they want to do, though.

fogster

Scheduled maintenance for my 2004 Highlander does not list the water pump, but sometimes dealers have their own recommendations beyond Toyota's; maybe that's the case here. As for the timing belt however: if you don't replace it, you might get another 5K out of it but the consequences if it breaks could be CATASTROPHIC, maybe requiring replacement of the engine. I definitely would not risk it. Timing belts seem to be one of those items like car batteries; tightly designed to "fail on schedule".