Boxerworks.com

I've just seen some solid evidence that pre-filling a new oil filter measurably reduces particles compared to a dry filter at start up.

Our airhead filters slide in sideways makes pre-filling impossible.

I would like to know if you soak your filters before insertion.

Or?

I've never thought of doing that, the only thing I do before starting the engine is crank with the plugs removed and lying on the heads until the oil pressure light goes out.

I can see no harm in pre-soaking the filter but with fresh clean oil where are the particles coming from to challenge the dry filter media. Another consideration is that the filter bypass valve probably opens on every cold start due to the high differential pressure across the filter with cold oil and that would negate any consideration of how efficient the filter media was.

I hadn't heard of "particle" issues with a new filter. What evidence have you seen?

I do not soak my filter...would be messy on installation. I change the filter as normal, then drop the float bowls with petcocks off. Then I hit the starter button until the oil pressure light goes out...takes probably 5-10 seconds. Then put the bowls back on. You could do the same thing by pulling the high tension leads on the spark plugs, insert extra plugs, and ground the threads of the plugs to the engine case.

I do prefill my car filters before I spin them on.

Kurt

Sorry, I don't actually get the logic behind that. Particles are carried to the filter by the oil so, surely, the filter will be oil soaked in any case. I'd be interested to see the evidence or at least be told just what evidence there is...

Rob

The particles are from dry start wear:

https://www.youtube.com/watch?v=939WTeorBnQ

I'm not real familiar with the oil system on my R75. But I think the filter is the last thing in the line before the oil just falls into the pan. So the oil is pumping through the engine as normal.

After reading the link below, the filter is not the last in line for the oil. When I have looked into the filter housing while changing the filter, it looked like it went through the filter and back into the sump. Looks can be deceiving.

If a spin on filter can be filled and installed, I will fill it. On my Guzzi's, I have to pull the pan to change the filter. When I go to install a new filter full of oil, I have to hold the pan upside down to spin it on. Even on the Guzzi, I think the filter is about the last thing in line before the oil goes back into the pan.

Tom

This is the oiling sketch for the engine. I would think that the path of oil defines how it works. First it's picked up from the sump. The oil filter is quite early in the circulation. Wouldn't you want to clean the oil before sending it out to the rest of the engine??

https://bmwmotorcycletech.info/oilsketch.htm

Kurt

I really don't think this is a big deal one way or the other. On a vehicle with a vertical spin on filter I can see the sense in filling it with oil but with our cartridge filter it would be a messy to pre-soak it and I can't see it achieving much. If you can't pre-fill then obviously there is going to be a few seconds of no oil pressure and cranking without firing seems to be the way many of us go. But even that can't readily be done on modern vehicles. My car has a vertical upside down filter so it can't be pre-filled and I can't crank it without firing. Even if there was a way it would probably throw an engine code. So what else is there to do but fire it up and let it idle until the oil light goes out. Like many millions of other vehicles it seems to survive this treatment. Airheads survive it too.

Thanks,
I'll definitively start priming the filter on my oilhead.