I did the search but didn't come up with too many useful matches...

how often the oil pump fail?
any useful link on replacing it?

1990 GXE (auto...140k)

 

Doing a search on, "oil and pump" would probably tell you. I have not heard of anyone having problems with their oil pump, it should last the life of the engine.

 

yeap, I searched the 'oil pump' but couldn't find any exact matches.
(there were one thread asking how to prime the oil pump...)

The reason I asked is because my mechanic tells me that my oil
pump is going out (some weird noise from engine compartment only
when gear is engaged...this is an automatic)... I guess I have to
do some isolation now that the oil pump does not likely to be the
case.

thanks davis4005!