I have an oil leak developing that appears to be coming from around the oil level sensor on an M113. From what little I can see, it looks like the bolts holding the sensor can only be accessed after removing the oil pan. Is this correct?

Do you think this is a simple matter of the bolts loosening up and allowing the leak? From the EPC, it looks like there's an o-ring or a seal on it, too. I'm wondering if a simple retorque would fix it, or if I should replace the o-ring or seal ring too. It's certainly not the most accessible item on the engine. That's for sure!

Thoughts?

__________________
1973 280SE 4.5 (Sold)
1984 LWB 280GE (Sold)
2000 G500 NMLE - "Deep Throat"
2007 ML320 CDI (Sold)
2010 Porsche Cayenne S Transsyberia TipTronic (Sold)
2010 Audi Q7 3.0 TDI (Sold and Sorely Missed)
2014 ML350 BTC
2015 Audi Q7 3.0 TDI (On Order)