I have a 93' 300ce w/104. I have had the car for about a year and put 21,000 miles on it. I changed the oil as I have allways (pump through the dip-stick) new filter. When I started it up this time after finishing and filling oil, the low oil warning lite came on when I started the car and has stayed on! I have good pressure on guage, no less than 2.5 at idle and 3 anything over 1200 rpm's. I have checked and re-checked the fluid level and it is just below the max mark on the dip-stick. I am gussing the sending unit for the low oil level is in-op or stuck. Where is the sending unit located? How do you go about checking what is wrong?