what do you remove to gain access to the oil pump on 1994 Buick Park Avenue

not getting enough oil to #5 valve lifter, lifter keeps failing. low oil pressure after engine warms up

Asked by for the 1994 Buick Park Avenue
2 answers
The engine bearings or oil pump may be worn out. The oil pump screen may be clogged, also. If the engine has a lot of miles or has run on dirty oil, the oil galleys may be blocked. It may be a good idea to drop the oil pan and check a bearing or two to evaluate the engine wear.
you have to remove the oil pan and the pump is located there.