[V8] Engine Oil Pressure Warning

[Gunter Lorberg]

Has anyone ever had problems with their 'Auto-Check' system engine oil pressure warning?
 
The black '90 V8 with 150 000 miles has been running well.  I have owned it for about 1 1/2 years.  My GF is the principal driver.  About two weeks ago she reported that the engine oil pressure warning came on (red warning accompanied by irratating tones) while driving on the highway without the car missing a beat.  She stopped, of course, and called me.  I was able to drive out to her to have a look at the car for myself.  Car ran well and oil level normal--warning did not come on while I was evaluating the situation.   I sent her onwards and it happened again several hours later.  It has been an infrequently recurring problem the past few weeks, and it happened most recently to me today when I briefly drove it around.  No signs of any mechanical distress.  I was sitting idling when it went off and was able to inspect the oil pressure gauge at the same time--the needle indicated normal oil pressure.
 
I can't think of any recent changes to the car that could account for this new problem.  I have always used the same oil (Castrol GTX 5W-30) which I realize is a little on the light side for the summer, but I have used this oil since taking over ownership without problem.
 
I am inclined to ignore this warning, but would prefer that it was operating properly.  I am concerned that it might incr. in frequency and become a real nuisance while serving no useful purpose.
 
Gunter
(2) '90 V8's