2002 Gen 1 Prius, 118K miles. I am coming up on my 120K servicing. As far as I can tell, my timing belt has not been replaced. When it is time, should I replace the water pump as well? I read an earlier thread about timing belts and couldn't tell if this was a chain or a belt car. If it has a timing chain, does that drive the water pump as well?
Prius has a timing chain, not a timing belt. Unless you hear lots of chain noise, there's no need to periodically replace the chain. It wouldn't hurt to replace the engine coolant pump at 120K miles. However you can see coolant weeping by looking at the interior of the pump pulley, visible when you open the hood and look down. So if you want, you could defer that replacement until you start to see a pinkish or whitish stain that shows the pump bearing is starting to leak. The engine coolant pump is powered by the serpentine drive belt. At minimum, you should replace the serpentine drive belt now if it was not previously replaced.
The NHW11 engine is rev limited to 4,500 rpm. In fact the normal control laws try to keep rpms under 4,150 rpm so it really has an easy life. I don't see the timing chain replacement as being called out for any given mileage so at 130,000 miles, I'm not headed that way. From what we've seen: 30k - replace transaxle oil based on testing 60k - inverter coolant 120k - test engine coolant 120k - test brake fluid (Doug has advocated) 120k - check struts 120k - spark plugs Bob Wilson
