Oil pressure sender

[tbrown@nosc.mil]

     Does anyone know a quick test for the oil pressure sending unit?  I 
     have an 86 Coupe GT.  My gauge is pegged and the idiot light and 
     buzzer come on intermittently although there does not appear to be a 
     genuine oil pressure fault i.e. I've had this indication for several 
     weeks.
     
     Also, is the sending unit the little 1 inch diameter tin can with two 
     terminals located on the block near the dipstick?  The Audi dealer 
     gave me a price of $148.00.  BAP-GEON gave me a price of $4.95.  
     Anyone have a legitimate part number???
     
     Tom Brown