When I changed the engine oil filter the other day I noticed the filter was not completely full of oil. The oil came to about an inch below the top of the filter. I’m thinking this is not normal and air is being sucked into the system someplace. Anyone have experience with this?

 

Did you fill the filter with fuel when you installed it? If so, is the filter on tight enough, without over tightening it? Was the rubber gasket properly installed? If all that is good, check the lift pump for leaks. Sometimes you have to pressurize the full tank to find suction side leaks...Mark

 

Thanks for the tips maybe368. My question is in regard to the engine oil filter not the fuel filter. But, the oil filter sealing rubber gasket was seated well as the filter was tight and did not leak prior to removal. I do fill new oil filters with engine oil prior to install.

 

Sorry, My brain just instantly read fuel filter, I'm going to give it a good whoopin' ...Mark

 

Mine is the same way, I think it's nice not having oil running all over when removing the filter.

 

Marf75, it is good to read that you have the same 'no mess filter change option'. The oil pressure seems to be OK; the gauge does wander at times. I am planing to try Jim Lane's electrical connector fix to see if that stops the gauge wander (link to Jim's fix: https://www.dieseltruckresource.com/...+pressure+wire ).

My concern is that I do not know if this (air in oil filter) is, or is not, a problem.

 

Maybe when the engine is shut down and as the oil drains from the passages
a little syphoning happens??

 

This happens on each of our company trucks (27 Dodge CTD"S) when we perform oil changes on them. Also occurs on my vehicles as well.

 

*Filters mounted such that oil tends to drain from them usually incorporate an anti-drainback valve to hold oil in the filter after the engine (or other lubrication system) is shut down. This is done to avoid a delay in oil pressure buildup once the system is restarted; without an anti-drainback valve, pressurized oil would have to fill the filter before travelling onward to the engine's working parts. This situation can cause premature wear of moving parts due to initial lack of oil.

the preceding paragraph was copied from wikipedia after googling anti drain back valve in oil filter. this also explains why its a good idea to fill the oil filter with oil prior to installation. not sure what kind of filters you guys were using where your finding an air pocket in the filter when changing, but its indicative of not being equiped with an anti drain back valve. whats going on is a siphoning effect upon shut down.

 

Thanks for all the feedback. It appears that siphoning is a likely cause. The filter just removed is a Napa ProSelect, 27620.

 

From your citation: This situation can cause premature wear of moving parts due to initial lack of oil.

This might pose a problem if the oil between the friction surfaces actually drained out, too. Believe me, there is a good film of oil clinging to everything, especially the crank and rod mains. If I watch carefully, I might see 1/2 a second without pressure after start up. Unless you're someone who revs a cold engine, I wouldn't worry too much about it.