good reason to NOT prefill your oil filter

[turbodog]

Prefilling puts oil on the downstream side of the filter media... straight to the engine when cranked.

This is not the first time I've seen this. Have noticed in mobil1 synthetic, delo 400, pennzoil, castrol synthetic, etc. No reason to think any brand is immune.

Caterpillar's official stance is no-prefill also...

 

[JimIslander]

Unused new oil is dirty?

 

[chillinn]

I have never prefilled my filters and didn't even know that was a thing. About the only thing I do that is questionable is grease the filter seal after dipping my dirty finger in the oil container.

 

[raggie33]

I've learned recently to not even use oil .. switch my motorized bike for a electric lol

 

[fredx]

So - isn't there oil there after the engine shuts down? It's there every time the engine is shut off and cranked back up. Besides the majority of the oil priming a new canister / filter gets absorbed / soaked into the paper element anyway. I have always primed mine and done so in the Military and @ the nuclear plant that I worked.

What's wrong with putting new clean oil " straight in the engine " any way? Arent you dumping all the rest of the oil thru the valve cover down thru the engine into the pan any way?

I for one dont see the issue

 

[turbodog]

Unused new oil is dirty?

Yes. They don't do micron-level filtering at the factory.

 

[fredx]

Well its clean enough for me

Now if I were riding' on the space shuttle....... Nah, still be good enough for me!

 

[turbodog]

So - isn't there oil there after the engine shuts down? It's there every time the engine is shut off and cranked back up. Besides the majority of the oil priming a new canister / filter gets absorbed / soaked into the paper element anyway. I have always primed mine and done so in the Military and @ the nuclear plant that I worked.

What's wrong with putting new clean oil " straight in the engine " any way? Arent you dumping all the rest of the oil thru the valve cover down thru the engine into the pan any way?

I for one dont see the issue

Oil poured into the fill hole ends up in the pan, and gets run through the filter BEFORE entering the engine's bearings.

Oil prefilled into the filter during a filter change is poured into the large center hole, which is the 'exit' hole of the filter, so debris can be sent straight to the bearings WITHOUT being filtered.

 

[fredx]

I'm still good with it

What's the oil looking like after 2K anyways?

 

[AstroTurf]

i fill em, and let them soak up as much as possible while i drain out the old oil.

then drain it (new filter) into the engine fill port, and install the new drained filter.

wah lah

 

[AstroTurf]

I'm still good with it

What's the oil looking like after 2K anyways?

amsoil 25k for me

 

[turbodog]

I'm still good with it

What's the oil looking like after 2K anyways?

Well good for you. This was not a post about oil brand, life, viscosity, additives, etc. It's about contaminants from the factory damaging bearings, journals, cams, lifters, VVT assemblies, etc.

Many people prefill filters in an attempt to prolong bearing/engine life. Ironically there's a real risk for the opposite to happen.

Maybe your signature says it all, which contains a typo, BTW.

 

[fredx]

I have tried to be friendly and not made any dispariaging remarks about you-- even liked all of your posts although I dont agree with you. I am about 99.9 % sure most folks would think your overthinking this automotive filter thing.
My experience has been when folks start to attack others they know they have lost the argument.
Well you just keep on doing what your doing!
Good luck to you!

 

[raggie33]

Another day on cpf lol .

 

[knucklegary]

So - isn't there oil there after the engine shuts down? It's there every time the engine is shut off and cranked back up. Besides the majority of the oil priming a new canister / filter gets absorbed / soaked into the paper element anyway. I have always primed mine and done so in the Military and @ the nuclear plant that I worked.

What's wrong with putting new clean oil " straight in the engine " any way? Arent you dumping all the rest of the oil thru the valve cover down thru the engine into the pan any way?

I for one dont see the issue

Fred, if you don't mind me asking, what are you driving that you're filling through valve covers?

Nothing wrong with a little crud getting into an old Big Block V8. Most of us ran heavy single weight non detergent, and didn't wait but 2000 miles for oil changes

 

[chillinn]

My experience has been when folks start to attack others they know they have lost the argument

What you're describing is the ad hominem, but to be fair, OP's screen name is not turbopaladin, and otherwise has not employed fallacy. In fact, he makes a pretty strong argument supported by documentary evidence of his experience yet without claiming to be an expert. I am even less than not an expert, but that looks like sludge to me. Meanwhile, your argument seems to be entirely based on

I have always primed mine

Tradition? turbodog shouldn't have said that, but he didn't come here for an argument, only to save others from grief. It's also possible, not saying this is the case, but it is also possible that like many here have, there may be some difficulty in recognizing mistakes. I'll tell you right now that I am wrong just to show you all how easy it is.

My theory sounds like sticks and stones, but is neurologically based. It is possible to be assaulted, battered, but taking offense is a choice. Feelings are important, certainly, but no one can hurt my feelings, because they are my feelings, and my body causes them. IOW, we do it to ourselves. Be tough. Don't hurt anyone, but don't get hurt.

 

[idleprocess]

Prefilling puts oil on the downstream side of the filter media... straight to the engine when cranked.

For sure - and this results in additional potential for wear. But I gather filters generally go into bypass mode under certain RPM conditions and during cold starts so there are routine instances of unfiltered oil being pumped into the engine.

The point that prefilling the filter does not obviate and in fact contributes to engine wear is however entirely valid. And on my present vehicles it would be folly to do so anyway - spins down on my daily driver and laterally on my occasional-use second vehicle.😆

About the only thing I do that is questionable is grease the filter seal after dipping my dirty finger in the oil container.

Same. I gather this results in better sealing characteristics in operation. An empty filter is also assumed for oil fills in every manual I've ever read.

 

[ABTOMAT]

I've always installed the filter dry and cranked it with the fuel pump relay pulled to prime the filter.

 

[knucklegary]

I've always installed the filter dry and cranked it with the fuel pump relay pulled to prime the filter.

We did same to freshly built motors but used the starter relay

 

[turbodog]

I've always installed the filter dry and cranked it with the fuel pump relay pulled to prime the filter.

Reminds me that some (all?) modern fuel injected vehicles have a crank bypass feature. Hold pedal down, crank engine. The injectors w/ shutoff until the pedal is released, allowing pressure to climb and the filter to fill.