Been monitoring a small oil leak on my 420SEL thats popped up in the last 3K miles/6 weeks. At first I thought it was from the filter housing O-ring as there was a little seepage from there. I know the O-ring that came with the WIX filter was a fraction smaller in rubber diameter. ( I'll never use another WIX for that reason.) But now I'm pretty sure it's eminating from the oil pressure sending unit under the filter housing. Because theres lots of splatter on things beside and behind it (in relation to the front of the car). Can't seem to catch it in the act while idling, so I'm thinking it does it while under throttle.


Does this seem logical? Or should I focus on something else? It's a pricey item to change if it's not the culprit.

Cliff