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There is no reason to change the water pump or the timing chain unless you suspect a fault.
First, inspect the water pump in the following manner...
Pressure test the cooling system. If the pump is leaking it needs replacement. Remove the belt. Spin the water pump pulley, it should spin free with no bearing noise. There should be very minimal play in the pulley when you jiggle it up and town in and out. If the bearings are noisy and the pump has excessive play, it should be replaced.
As for the chain...
Timing chains are designed to last as long as the engine. But, there are instances where one of the chain guides, the tensioner may fail and cause a rattle. If this is not repaired, then problems arise. But if the chain is making no noise, then there is no reason to replace it.
There is no reason to change wither comonent unless you see a problem with it.
Thanks; I do hear a "bird/tweet" in the engine frequently when things are cold and then it usually goes away when the engine warms up. I assume there's little chance that's the water pump and more likely a belt (which none have been replaced).
What you will do is remove he belt. Spin ALL the pulleys, idlers, tensioner, alternator, compressor, and the waterpump. You will wobble the pulleys. If any are growling when spun or have any excessive play, they il be replaced along with a new TOYOTA belt. Please save yourself the headache and use a Toyota belt.
Thanks much, bu the Toyota belt, I assume you mean the serpentine belt?
Yes that would be correct.