1987 vw vanagon blinking light/alarm?

my oil light on 87 vw vanagon
starts blinking and making horrid noise after 10 miles of driving. oil is full, and engine is not overheating. other that the fear of impending doom for my vanagon because of the warning signals, everything seems to run ok.
what is wrong?
gary carter, June 2005


done
warning of low oil pressure. posssibly big problem or faulty sensor, mine went off after the head gaskets blew (big problem) so sounds strange before a prob if it still runs sweet,

Robin, November 2005