Originally Posted By: goodtimes
Oil pumps wear and produce less flow, and it will take longer to fill a filter chamber in a 300K car compared to a new car. The lobes wear or the sides wear, but they do wear and they are high precision parts. They are precision made for a reason.
Shouldn't really matter if the ADBV is working 100% and the oiling system remains full. The OP was complaining of a long oil light with the M1 filters (which failed the ADBV blow test), but with other filters his oil light would go off much quicker.
Originally Posted By: goodtimes
In this case the filter is base down, the oil galleries aren't draining into the filter.
Depends on the exact location of the filter. In any case, even if the filter is mounted high with the base down (like it is on my '05 Tacoma), if the ADBV is leaking then the filter will drain down. If the bypass valve is leaking, it still won't drain down the filter if the ADBV is working 100%. Only exception to that is if the bypass valve is located in the base of the filter and the filter is also base down, then a leaky bypass valve might allow the filter to drain the same as if a leaky ADBV would.
Originally Posted By: goodtimes
It does matter if the bypass valve allows air in or not. Try making a hole in the top of a draining filter, and see almost all of the oil drains out with a perfect sealing adbv. It will drain down to where the media stops.
Like I said earlier, punching a hole in the can of the filter and allowing atmospheric pressure inside the can is way different than a filter mounted on an engine with no hole punched in the can. It's two totally different scenarios.
The only real way a filter can drain out on the vehicle is if the ADBV is defective.