I recently bought a 2001 Sports Trac.  The original owner has told me that
once it gets cool outside the engine oil pressure gauge doesn't function for
the first few minutes.  Well, it's getting cooler outside and the gauge is
doing exactly what he said it would do.  When I start the track, I have no
oil pressure(on the gauge, there is no tapping or any other indication I
actually have no oil pressure).   Once I drive the truck about 1/2 mile the
gauge snaps up to it's normal position.

Does anyone have an idea as to what this could be?  Sending unit, something
in the dash, any ideas?

Thanks!
Jim