1998 E320 4matic - warning lights / starting problem

[jenningsm62]

I have a few warnings indicators on the dash display and a starting problem:

" oil sensor defective" this comes up on dash display with key in position 2. It is intermittent, doesn't happen every time. Oil level is OK on the dipstick.

FSS indicator comes on, indicating service needed in 1200 miles. Has a wrench symbol.

Starting problem - this happens rarely, but it does keep happening. Turn the key to "start", the engine turns one revolution and stops. Wait a second, try again, it starts fine. Has happened 3-4 times in 6 months in all kinds of weather, hot or cold. Don't understand this. Worried that sooner or later, it won't start at all.

Any suggestions?? Looking for some advice and input please.

Thanks, Mike