Prefilling Oil Filters - Necessary?
- Thread starter BackwoodsAL
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I would say it would make it HARDER as it is an obstruction along the way to the oil pump to evacuate air,
Think of water hammer. Unless you could fill the drill all the way back to the Pump.
I used to prefill. when I had VVT rattle after oil change.
It Didn't do anything that I could tell.
Then, For a while I half filled them. So the pump could push the air column out quickly, without a slug of oil travelling at
high speed like a bullet, then whacking into who knows what inside the engine.
On the new Subaru series it doesn't matter as the car starts DRY every time after a hot cool-down.
Every time.
Somehow its still running. But not quietly. I don't think the stationary HLA are as happy as they once were.
But at least you don't have to adjust them. Just tear the whole engine apart to replace them at great cost.
What progress!
Zee09
$200 Site Donor 2023
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I have done that but a filter used like that can be loaded up the night before and you can get a lot
of oil in one if you let it soak overnight- no mess either- but as stated not required.
I have always prefilled but I would bet hunderds of thousands of filters are screwed on at fast-lube places empty every year. Can't imagine it makes much difference but I prefer to minimize the time without flow at start-up.
If a slug of oil hitting parts was detrimental, you'd see damaged engines all over the place because the majority of oil changes do no involve pre-filling the oil filter.
gathermewool
Site Donor 2023
I just pre-filled the upside-down filter on my Subie and it went well. I filled it to the brim and let the media soak up as much as possible, which was all but a little in the bottom of the center hole. I then rotated the filter horizontally to distribute the oil and installed it. Not a drop was a lost.
I do not pre-fill because I always worry about spilling oil. If I had a hoist where I could stand underneath my vehicles it would make pre-filling easy. The Jeep is impossible to pre-fill and my F-150 has a sideways filter. The Honda is kind of difficult to pre-fill as well. My Corvette could be pre-filled however its so low to the ground and not worth even trying. I was at a car show one time and they had a car that was run without oil wide open until it quit. People could buy tickets and write down how many minutes and seconds before it would quit. The engine about 10 minutes before it finally seized. It was run without any oil in it. I believe the layer of film on the oil is enough to protect the engine for a couple of seconds. I believe a flooded engine is much harder on initial startup than running with an empty filer after a new oil change. The trick is keep decent OCI intervals and maintain your vehicle if you want it to last a long time.
There will be no slug of oil - compressed by an air column - with a filter that was NOT pre-filled.
My exact point.
Thank you
Again do a partial fill on larger filters - but not all the way - unless you can also pre- fill the drill down to the oil pump.
I do this on the FB subaru by pouring oil in the filter adapter outlet and the inlet, then quickly screwing on the filter.
Actually a waste of my time as these dry start every morning to to an empty inverted filter.
Another Stupid Subaru engine design.
Time they go to a "slant" I4 and get away from this garbage engine design.
gathermewool
Site Donor 2023
There will be no slug of oil - compressed by an air column - with a filter that was NOT pre-filled.
My exact point.
Thank you
Again do a partial fill on larger filters - but not all the way - unless you can also pre- fill the drill down to the oil pump.
I do this on the FB subaru by pouring oil in the filter adapter outlet and the inlet, then quickly screwing on the filter.
Actually a waste of my time as these dry start every morning to to an empty inverted filter.
Another Stupid Subaru engine design.
Time they go to a "slant" I4 and get away from this garbage engine design.
Shirley you jest.
gathermewool
Site Donor 2023
That boxer looks weird...
It's a V8 from a Porsche 928, but it was hit hard on the driver's side ....
I never pre fill the little 7317 filter for my Honda but if I had a 2 qt filter I would consider it. However, as mentioned earlier the oil film is probably more than sufficient during the 2-3 sec it takes for the pump to fill the filter and other areas.I always prefill the 2 qt filter on my Silverado
I never do it, all our cars have sideways filters so it would be a messy faff and there is plenty of oil inside the engine so I’d never worry about a dry start. I could see the benefit on large class 8 semi trucks where you’re putting like 15 gallons of oil in and the filters are enormous and can take a couple of gallons each.
I guarantee someone on this site has bought a jig like this purely so they can pre-fill their horizontal filter.
My Chevy dealer pre fills anything I give him.Hey, guys. I know, I'm sure I am beating a dead horse and it's inevitable I'm going to annoy some people with this question. For years, I have prefilled (as much as I can) the oil filter on my F-150, in an effort to help the engine receive oil flow to the bearings, as soon as possible. I'm getting ready soon to do the first DIY oil change on my 2007 Mercury Grand Marquis that I recently purchased and I'd like to hear your opinions on prefilling the oil filter before installation.
Being that the Modular engines in light duty Ford F-Series pickups and Ford Panther Platform cars have horizontally mounted filter angles, it somewhat makes it a bit more challenging to prefill the filter, without spilling, which pretty much limits me to only a halfway prefilled filter, at best.
So, now to the point: Being that the filter these engines take only holds about maybe 1/2 - 3/4 of a quart of oil (if it is completely filled to the top), is there really any scientific advantage to prefilling the filters before installation, or is it negligible? I've been on the fence on this topic for a long time now and I've never actually asked anyone else for their opinion on this topic. Just always used this method, based on my own assumptions. Thanks!
No not necessary but kind of fun kinda like OCI foreplay!
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