Pre-fill OF

[Reloader59]

Prefilling is the exact reason why most filters have an anti-drain back valve. To eliminate dry starts. Funny how people are cutting apart filters to show what's inside, Talking about the "silicone" anti-drain back valve, yet some overlook its true design. It's there for a reason and it's the reason you pre fill the oil filter. Doesn't matter the position of the filter, it can still be partially filled or the filter soaked in oil.
And filters that don't have a valve will usually have one built in the engine.

 

[ZeeOSix]

I prefill if possible.

Years ago I was at a customers house, in a basement where the water filters were. THe customer had complained about sediment in the water, and had explained that he had changed the filters recently....like the one pictured on the bottom....

After a little diagnosis, I found that there was damage to the filter near the seam, looked blown out a bit.. I changed the filter and turned the water back on, in the way it should be turned back on, slowly.

Of course the customer was perplexed by the slow introduction of water into the vessel. The original installer had told him to turn the water on as quickly as possible........I them understood how the filter had internally burst.

Understand there are some differences between the closed nature of a plumbing system and the open system of an engine, but the principle is similar.

Of course, oil filers are more robust, than these filters.......but filling the filter cannot hurt.

If an oil filter was dry or completely full of oil, if someone cold stated the engine and it went to near redline very quickly (I've actually seen someone do that - lol) causing max oil flow rate and near instant max dP (like your water filter example), it's possible the filter media could be damaged too. Even more so the colder and thicker the oil is, and if the filter was dry it would also take longer for the oil pump's pressure relief valve to react and cut back some flow.

The filter bypass valve might help mitigate damage from such a scenario, but if the max flow happened very quickly, the bypass valve may not react fast enough, and most filter bypass valves aren't really meant to flow a lot of bypassed oil (ie, small diameter flow area).

 

[burbguy82]

If an oil filter was dry or completely full of oil, if someone cold stated the engine and it went to near redline very quickly (I've actually seen someone do that - lol) causing max oil flow rate and near instant max dP (like your water filter example), it's possible the filter media could be damaged too. Even more so the colder and thicker the oil is. The filter bypass valve might help mitigate damage from such a scenario, but if the max flow happened very quickly, the bypass valve may not react fast enough, and most filter bypass valves aren't really meant to flow a lot of bypassed oil (ie, small diameter flow area).

I agree, which is why I prefill if possible. The only ones I cannot (horizontal mounted) I soak a bit with oil\fluid just to give it a better chance.

 

[Mechanician]

I've only had one instance ever, where prefilling a filter caused a problem.
Back in the early 90s there were few VW Golf oil pumps with sticky pressure relief valves.
During cold start the car would start, then die. The engine would lose all compression, due to the hydraulic lifters floating the valves. Had one where the oil filter exploded.
The pressure relief was built into the oil pump and sealed, the only repair was replacement of the oil pump.
After I replaced an oil pump, I prefilled the filter and started it, and found it would not build any oil pressure.
The pump was not able to prime itself, the air in the galley was not able to clear, due to the oil ahead of it.
Installed a new empty filter, and the problem was gone.

 

[Al]

People who are OCD SHOULD prefil their filters. Also those who expect to keep their vehicle for more than a million miles.

 

[350Rocket]

People who are OCD SHOULD prefil their filters. Also those who expect to keep their vehicle for more than a million miles.

I'd say more like 400k miles or 20,000 hours maybe.