Hello all, I have just had my car serviced and the oil light comes on when it is idling. It  has done 160k it  is diesel and has been running fine. Could it be the sensor?

It could be the sensor, but with 160,000 miles on the clock its far more likely the engine has just run out of miles

What engine size. Years ago I had a car with this problem which was because the spring had broken in the oil pressure relief valve. My brother had this problem recently in his Audi TT. He hadn’t changed oil for years. It was because the oil filter was clogged up. New oil filter cured it. 

the spring on the oil pressure relief valve is made of Chinese's finest, almost good enough for a road bridge in italy.... the good news on many is its external, but no idea where u get a replacement spring that's suitable (other than buying a whole pump)

 

 

What oil filter did you use? Has it been fitted correctly?

1 hour ago, Botus said:

but no idea where u get a replacement spring that's suitable

Just do a Google search on "engineering springs" there are lots of options all for about £12