For the last several months, every few weeks the oil failure indicator light comes on and the oiol pressure guage drops to zero. This may last from a few seconds to a nerve racking minute or two. Then it bouces back to full pressure. I have checked the oil level and it seems ok. Does this sound like a problem with the sending unit? Any advice?

 

Don't be worried about it.

It would be probably the oil pressure sensor:

 

Yup I agree mine actually has stopped working a few times this year as well. Though not bad enough to warrant a special trip to the mechanic.

 

The oil sensor has two conections. Sometimes one of them begin to fail and sometimes they keep on running well.

The sensor gets dirty as is located in an area where It's not well protected.

I'm going to show you a Carrera 4S oil sensor from a buddie. His car is in Spain , but was imported from Germany, and got a lot corrosion from the salt roads in winter time.
We call it The Titanic (cause of the corrosion)


Compared it to mine (upper pics)







Compared it to mine (upper pics)




To access to the oil sensor to work in the engine lid, Porsche dealers get down the engine, and replece it properly without effort.
My mechanic made by himself a special tool to manipulate the screw without gtting down the engine