Leaking Oil sending Unit-2004 Quest

[mwd571]

I have replaced 4 sending units , still leaking. Are they all bad or is there something I am overlooking?
Thanks

[dtownfb]

Did you replace them yourself or did the dealership do the work?

[Ithinkican]

If you are sure that the oil leak is coming from that area, replace the oil cooler oring, which is behind the part that the oil filter screws on to. I've yet to see a leaking oil sending unit on a 3.5L.