Nissan Repair: Oil leak, nissan altima, rubber gasket

Question
1998 Nissan Altima 4cylinder 68k miles
After a recent oil change we have had small amounts of oil leaking.
Mechanic told us it was not filter or the oil pan but something called an oil simulator..
What is an oil simulator?
What does it do?
I hope this is not a difficult or costly repair.

Thanks

Answer
I do not know what the mechanic is calling an oil simulator.  He is probably talking about the sensor that lets you know if the oil is low.  Some vehicles have a sensor in the pan that reads the level of oil and they tend to leak after a few years.  That would be my guess from what you have said.  You could put the car up on a lift and check for a wire going to the pan and see what you have to do to remove and replace the seal.  I have  just pushed them back in on those that I have seen and that has corrected the problem.  The center section just pushes back into the rubber gasket.