Never Prefill oil filters!

[ZeeOSix]

Originally Posted by quint
As far as prefilling a filter, if I were you guys I'd be a lot more concerned about the cleanliness of the filter before I'd worry about anything in the oil. I've done oil changes on maybe a dozen cars in the last year, and on every filter I have been able to wipe away metal flakes from the center threaded section, and a black, dusty dirty substance from the oil inlet holes and accessible interior exposed surfaces. Some of these metal flakes are alarming. Fram Ultras, Kia OEM, Mazda OEM, Purolators, you name it. Every single one of them. I wonder how many people actually think to do a thorough (as possible) cleaning of the filter surfaces before they install it. BITOG people, probably a high percentage. The rest of the world? Probably a very low percentage.


Very good point. It's always good to inspect and clean up the filter as much as possible before installation. Most of the time there will be some contamination on the base plate mounting hole threads. I always clean the threads up. Look down inside the center tube with a good flashlight and look for any debris or anything that looks like it could break off and go into the engine. I use the strong LED light on my cellphone at the store when buying a filter to look down the center tube - better there than at home.

 

[ZeeOSix]

Originally Posted by CT8
Originally Posted by ZeeOSix
Like I said before ... the delta-p across the media is dependent on the oil viscosity and oil flow. That would be no different if the filter is full of air or full of oil.

It does


It does what? Not sure where your misconception is on this. The delta-p doesn't change if the viscosity and flow doesn't change. The flow will not change (positive displacement pump) just because the filter is empty and full of air instead of oil. DoubleWasp explained it pretty well in this post - LINK

 

[Shannow]

Viscossity of air us around …. nothing … while it is flowing through the filter...no DP...no bypass

 

[ZeeOSix]

Originally Posted by Shannow
Viscossity of air us around …. nothing … while it is flowing through the filter...no DP...no bypass


Exactly ... that's another good way to put it.

 

[Mr Nice]

I agree its best to prefill oil filter .

 

[Shannow]

You claim it's unimportant, but are up to post four, and now it's best to.

Please explain "why" it's best...

 

[dlundblad]

I prefill even if the filter faces down.

It makes a mess, but what's left inside is very beneficial.

 

[Shannow]

Originally Posted by dlundblad
I prefill even if the filter faces down.

It makes a mess, but what's left inside is very beneficial.

And how is it "very beneficial" ???

 

[Job]

The talk about dirty new oil is odd. Caterpillar states somewhere that when they looked at contaminants in new oil under a microscope, they found them to be largely organic matter. Lint basically, from the air. I have never seen anything settled out of oil even after years on a shelf. Additives shouldn't be particles or separate fluids of something they should be in solution with the oil spread evenly throughout. If it were a mixture they would say shake the bottle on it, like a medicine does. Someone posted this link, don't see any contaminants.

http://pqiadata.org/Toyota_0W20.html

 

[CT8]

Originally Posted by Shannow
Viscossity of air us around …. nothing … while it is flowing through the filter...no DP...no bypass
What would be then the pressure differential between the room temperature oil on the outside of the filter element and the inside of the element with out oil in it?

 

[DavidJones]

I attempted to prefill the filter on my 2.7 Ecoboost. Made a [censored] of a mess..........

 

[dlundblad]

Originally Posted by Shannow
Originally Posted by dlundblad
I prefill even if the filter faces down.

It makes a mess, but what's left inside is very beneficial.

And how is it "very beneficial" ???

I was thinking my post was so rediculous nobody would take it seriously.

 

[y_p_w]

Originally Posted by dlundblad
Originally Posted by Shannow
Originally Posted by dlundblad
I prefill even if the filter faces down.

It makes a mess, but what's left inside is very beneficial.

And how is it "very beneficial" ???

I was thinking my post was so rediculous nobody would take it seriously.

I'm so used to it I'd probably still do it if I had a Subaru with the base pointing down. I frankly don't "fill" the can with oil. I mostly just wet the media so that it's "primed".

I've changed the oil in cars in my family where the oil filter base is straight up. Several GMs and my WRX. I heard there was an alternative to the common AC PF47 filter that didn't have an ADV. However, I've heard it may not be the greatest idea because it's not just an ADV but serves as a check valve in case there's back flow.

 

[Purpfox]

Originally Posted by DavidJones
I attempted to prefill the filter on my 2.7 Ecoboost. Made a [censored] of a mess..........

lol, I never thought about trying that. i could see it turning into a splatter fest.

 

[ZeeOSix]

Originally Posted by CT8
Originally Posted by Shannow
Viscossity of air us around …. nothing … while it is flowing through the filter...no DP...no bypass

What would be then the pressure differential between the room temperature oil on the outside of the filter element and the inside of the element with out oil in it?


The same as if there was oil in the filter. Delta-p is only caused by the flow and viscosity going across the media ... and it doesn't matter if there is air or oil on the outlet side of the filter. The delta-p across an empty oil filter will be the same at start-up just as if the filter was full of oil. Oil pressure on the dash is not going to jump up significantly until the oil is way past the oil filter and filling the tight flow passages inside the engine's oiling system. Oil pressure seen on the dash has nothing to do with the delta-p across the filter or when the filter bypass valve opens.

 

[ZeeOSix]

Originally Posted by Farnsworth
The talk about dirty new oil is odd. Caterpillar states somewhere that when they looked at contaminants in new oil under a microscope, they found them to be largely organic matter. Lint basically, from the air. I have never seen anything settled out of oil even after years on a shelf. Additives shouldn't be particles or separate fluids of something they should be in solution with the oil spread evenly throughout. If it were a mixture they would say shake the bottle on it, like a medicine does. Someone posted this link, don't see any contaminants.

http://pqiadata.org/Toyota_0W20.html


PQIA doesn't measure contaminates ... no particle count data seen.

 

[JeffKeryk]

I simply prefill filters just enough that the media absorbs it.
Unless it's a real tiny filter like some Nissans.
If the filter mounts fairly vertical, I fill it most of the way.

Why is it better?
Cuz I feel better about it.

But that's just me.

 

[y_p_w]

Originally Posted by JeffKeryk
I simply prefill filters just enough that the media absorbs it.
Unless it's a real tiny filter like some Nissans.
If the filter mounts fairly vertical, I fill it most of the way.

Why is it better?
Cuz I feel better about it.

But that's just me.

Sure. A lot of people who at least do simple fluid changes on their own cars do a lot of little things just to feel better about it. I certainly do. I usually let the oil drain to the point where it's barely dripping out of the drain hole, even though it might take 20 minutes to get to that point and it's only draining out one-tenth of a quart more. When I've gone a while over the OCI (time or mileage) I might even pour a bit of new motor oil in there with the drain open to supposedly get out whatever gunk is in the pan. No shop is going to do that. They want the drain to be quick - maybe 2 minutes where about 98% of what's coming out is out.

But I certainly understand that what I'm doing is highly unlikely to provide any benefits that I'll ever notice.

 

[Job]

Originally Posted by ZeeOSix
Originally Posted by Farnsworth
The talk about dirty new oil is odd. Caterpillar states somewhere that when they looked at contaminants in new oil under a microscope, they found them to be largely organic matter. Lint basically, from the air. I have never seen anything settled out of oil even after years on a shelf. Additives shouldn't be particles or separate fluids of something they should be in solution with the oil spread evenly throughout. If it were a mixture they would say shake the bottle on it, like a medicine does. Someone posted this link, don't see any contaminants.

http://pqiadata.org/Toyota_0W20.html


PQIA doesn't measure contaminates ... no particle count data seen.



It's on the page to see.

 

[ZeeOSix]

Originally Posted by Farnsworth
It's on the page to see.


I must be blind today ... got it. It's in ppm instead of the typical ISO cleanliness code format, and only of metallic type particles, not all particles regardless of make-up.