> On the 3.5 SE, where exactly is the water pump? My guess is that it located
> inside the time chain housing and driven either the time chain or gears.
This is correct it is driven by the timing chain
I know on my senta is was external. But on the altima, how long does a
nissan
> water pump last and if every would need to be replace,
no telling , it all depends on the customers maitenence of the cooling
system
would it be
> expensive?
yes
Also if it driven by the chain, would it shorten the chain life?
No