No oil in filter... what gives?

[GLPalinkas]

A friend of mine (yes, really) has the RV-6 described below. He is the builder and it's been flying for 4-5 years (350+ hrs, I believe). He did an oil change the other day and found that the filter did not have any oil in it. Oil pressure and temp are ok.

What would cause a engine to not have oil in the filer if pressures are good? The fact the pressure is good must mean the oil pump is working ok (or bad sensor?) How about the vernatherm? I think the vernatherm only limits the oil flowing thru the cooler, right?

Additionally, recently his cht's have been elevated. Oil flow problem of some kind, I think, but what?

Any help appreciated.


RV-6 Flying
Mattituck TMX-360 (I believe)
Carb
Fixed pitch Sensenich

[airguy]

My guess is he's using the filter without the anti-drain-back valve, filter is draining to the crankcase on shutdown. Bad part of this is that oil pressure won't build on startup until the filter is filled by the pump.

[Noah]

Completely dry? Oil Filter Adapter Gasket installed backwards or wrong gasket preventing flow to filter?