PlsTell me what you know about filling oil filters

[ryan_of_the_e34]

A little preamble.
I'm writing a sample technical definition for a graduate class. I chose to do it about the pre-filling of oil filters. Any information that I gather WONT be published anywhere, nor posted on the internet. This assignment isn't going to be technically rigorous; it is only meant to give the student a workout at defining a problem and arranging text/text columns (and pictures) in a rhetorically sound (and aesthetically pleasing) way.

With that out of the way....
I would appreciate it if I could get this thread filled with information about the pre-filling of oil filters. ANY INFORMATION at all--i. e., you started pre-filling because your father/grandfather/uncle &c. told you to do so when he started to have you "help" him during oil changes, or if you started doing so because the oil filter package, itself, notes that you should do so (in the event that the latter is the case, I'd really appreciate you telling me which vehicle/filter brand recommends doing such). If you were directed to pre-fill because of a brand specific service manual PLEASE tell me as much as you can about your situation. If you have real-life information about WHY people should pre-fill, please pass it along.

If you don't pre-fill, please feel free to tell me why. I'm trying, as hard as I can, to learn about Cummins' recommendation to not to pre-fill (WRT the oil bottle seal under the bearing situation). If you have any examples of equipment manufacturers recommending against pre-filling, please pass them along. If I could address this topic by spending a couple of hours on journal databases, I would, but such is not the case.

Furthermore, if you know anything about motor oil cleanliness standards (at time of packaging) please pass that information on. Some of the arguments against pre-filling have to do with allegations of motor oil being inherently "dirty" in the bottle.

I pre-fill, so I'll offer that tidbit about myself. I have a few weeks to get this matter done, so please don't think that I'm attempting to have you all "do my homework for me," so to speak, by means of my request. The frequency of this practice seems to be predicated on a complicated matrix of criteria that necessarily requires that I ask mechanically inclined people about it to find out information about it.

Thanks

Edit: tl; dr version: please tell me everything that you know about oil filter pre-filling.

 

[addyguy]

It's not necessary, period.

If you read any official, or even un-official guide on how to change oil, there is rarely, if even, instructions to pre-fill the oil filter.

Millions upon millions of cars have OCI's done with no pre-filling of the filter - just grab filter, screw on, fill engine with oil, and fire'er up.

You don't see these millions of engines littering the raodway and junkyards from dying early. Even after sitting for a bit, engine still have an oil film on the parts, plenty to lube the engine before new oil makes it thru the new filter.

Just one opinion.

 

[jeepman3071]

I've been changing my own oil on cars and various farm machines for about 6 years now. My boss at the time (neighbor who owned a farm) taught me to pre-fill the oil filters when changing the oil.

In my opinion, pre-filling the oil filter with potentially "dirty" oil is a much better idea. The oil will only momentarily be run through the engine and then pass through the filter. Starting the engine with an empty filter will cause a "dry start" scenario and will cause much more wear than "dirty oil" would.

 

[Loobed]

I think I learned about pre-filling the filter when I was in High School auto shop. The teacher said to do it because it lessened the amount of time the engine was without oil. I think that the old 1950's Chevy small blocks needed to be pre-filled because they held over a quart of oil by themselves. They used very large canister filters.



http://www.classicchevy.com/chevy-oil-filter-canister-1956-1957.html


I do it to wet the filter media and to reduce the amount of time the engine is without oil. I don't fill it to the top: Usually I fill it 3/4 full. Sometimes I drop the canister and the oil spills out. I will pour a little in the filter to wet the filter media, and lube the threads and gasket, even if the filter goes on horizontal.

 

[EricF]

back 25yrs ago I was a young punk kid who thought he knew everything. Well a mechanic was prefilling oil filters (where applicable) and I asked him why. His response was because the oil pump has to take time to fill an oil filter first before it sends oil thru the engine. so by prefilling the filter, it eliminates that "dry start" time by possible a second or 2, which realistically is probably nothing, but in the back of his mind, he just helped that engine by a few seconds and allowed pressure to build just a bit faster and that was a good thing.
Also by prefilling he said he said it preps the paper element inside for oil and a high burst pressure of oil won't "shock" the paper and thus possibly causing something to get disrupted internally. And also it helped him fill the oil sump to the correct level before he started the engine.

To this day I prefill oil filters when I can. On those cars like some Toyota's where the filter sits topside down and relies heavily on the ADBV, you can't prefill it. but what I do is prep the filter by filling it to the top and just slow spin it until the filter media absorbs the oil.. to me the media is wetted and in the back of my mind I shouldn't have any shock to the filter as if it were dry. I do this for filter that I can't prefill all the way. if a filter mounts horizontally I fill what it with whatever I can and when everything settles I spin it on real quick and go for it.

I've never seen any manual that says to prefill a filter, I do it to help prime the system I suppose.. it's probably a mechanics myth, but I do live by some of them.
In the end.. can it hurt? Honestly... no.

as for oil being dirty in the bottle.. well so what? what about the possible shavings from the oil filter media that potentially will get pushed into the engine first? Or dirt/dust/debris from the filter packaging? not all oil filters have a seal on the base, although I found that a lot of the white box branded filters have the cellophane seal attached to the base.
I believe honda filters have this?

I personally am not worried about dirty motor oil out of the bottle because if it's dirty oil in the bottle it's because I put it there.

 

[HerrStig]

Hard to prefill a Toyota filter which is mounted base down. I used to do it on my Saab 900s which mounted filters base up but usually spilled some anyway.

 

[david_ES2]

My bone head says if the filter hole angle screws up right and fill the oil filter without possibly spilling it all over while trying to screw it on, then why not? Now if the filter goes on completely sideways...forget it.

 

[Chris Meutsch]

I've never done it. So far, I've never blown an engine.

 

[bullwinkle]

Actually the reasoning by Cummins on not pre-filling is related to the piston cooling nozzles that spray oil up onto the underside of the piston-the foil can clog the tiny spray hole, resulting in piston overheating and possible burn-through. I don't think foil would be capable of damaging a bearing, other than clogging a hole/passage somehow.

 

[ARCOgraphite]

Prefilling a filter COMPLETELY will put a slug of oil "blockage" between the "pipeline" of air between the oil pump and the filter, then, also, the big manifold pipeline of oil in the main gallery which feeds the main bearings and other vertical feeds. This will NOT help an oil pump that lost prime or regain prime as the ADBV will prevent drainback to the oil pump and, again, the slug of viscous fluid will be inhibiting the movement of the feedline of oil from the pump. Now 1/2 or 2/3 filling the spin-on filtercan will not be an impedement on a horizontal filter mounting position or base UP mounting position as there would still exist an air cavity would in the can near the base-end to allow the free filling of the filter and then into the main drill. Fianally various slugs of oil in the drill can lead to water-hammer like "bullets" though which seemingly benign are, just by their existence,troubling. Amazinly this complete pressurisation process can take less than 5 second on a dry start.

- Arco
B.S.M.E., NIASE MASTER (both very yellowed and dusty)

 

[CarbonSteel]

Originally Posted By: ryan_of_the_e34
Some of the arguments against pre-filling have to do with allegations of motor oil being inherently "dirty" in the bottle.

Jim Allen is doing some work now on how "dirty" new oil is in the bottle, but this "dirt" is miniscule if my particle test results are any indication and one could wonder "does it matter"?

I have a 2010 Ford F-150 and the oil filter is attached at about 15 degrees or so below horizontal. I do partially fill the filter when changing the oil. No old traditions handed down, just seems like the thing to do to lessen the "fill time" on the filter and thus the overall time to full lubrication. Would it cause a problem if I did not partially fill? No. How much time is saved in "fill time" by partially filling? Indiscernible; but there is a bit of comfort factor there and so I do it.

However, I owned Chevy trucks in the 1990's that had filters hanging straight down from the engine. On that application, I would tend to argue a little over fill time especially when using the longer filter over the shorter one:

Long Filter:

Short Filter:

While I could certainly be wrong, when using a long (empty) filter, I think there would be detectable difference in the time the engine cranked to seeing pressure on the oil gauge versus the same situation using the shorter filter (i.e. engine goes a bit longer without full oil pressure).

Anyway...hope this helps in some way (I submitted the last paper in the last class that I need for my MSCIS/ISS last night--so I feel your pain regarding homework assignments).

 

[sdan27]

I don't worry about it too much when it is a small quart-sized oil filter on a typical commuter vehicle. Usually those will fill up so fast anyway that the vehicle won't even have time to blink a low oil pressure light. On larger pieces of agricultural equipment or OTR trucks that have filters that can be as large as 4 or 5 quarts, I do prefill the filters. Some of these engines will have fuel filters that are spin-on filters and are as large as a quart or two and those you usually have to prefill with fuel becaue there is no other way to prime the system once you take the old filter off. I'll usually use some type of a diesel fuel additive to prefill fuel filters because it comes from a sealed container that should not have any dirt or debris in it. I figure the straight shot of additive should do good to help maintain the injectors and keep them clean and stuff. I never used to do it but I've also begun to prefill hydraulic and transmission filters on ag equipment. Those can be even larger than oil filters some times and when you change the oil and filters out and don't prefill the filter you can hear the air moving through the hydraulic system for a couple seconds or so.

 

[bullwinkle]

Also, I used to prefill, but when I found that NO professional mechanics were doing it, I quit. The EP/EW additives in the oil will protect the bearings for the second or so that it takes to build up full pressure, and oil FLOW, not PRESSURE, is what protects bearings from damage.

 

[Quattro Pete]

In both our cars with cartridge filters on top, pre-filling is not even possible. Not that I'm saddened by it...

 

[RF Overlord]

Originally Posted By: EricF
I've never seen any manual that says to prefill a filter, I do it to help prime the system I suppose.. it's probably a mechanics myth, but I do live by some of them.
In the end.. can it hurt? Honestly... no.
^^^This^^^
Originally Posted By: 2010_FX4
I do partially fill the filter when changing the oil. No old traditions handed down, just seems like the thing to do to lessen the "fill time" on the filter and thus the overall time to full lubrication. Would it cause a problem if I did not partially fill? No. How much time is saved in "fill time" by partially filling? Indiscernible; but there is a bit of comfort factor there and so I do it.
^^^And this^^^

 

[ryan_of_the_e34]

Originally Posted By: Quattro Pete
In both our cars with cartridge filters on top, pre-filling is not even possible. Not that I'm saddened by it...



I have a car with a cartridge type filter on it (a BMW with the m50 24v I6) and i'll pour a small amount of oil into a baggie and allow the filter element to soak--I'll also toss a little bit of oil into the canister itself. Not for any meaningful reason other than peace of mind.

Thanks for your responses thusfar, everyone.

 

[Quattro Pete]

Originally Posted By: ryan_of_the_e34
I have a car with a cartridge type filter on it (a BMW with the m50 24v I6) and i'll pour a small amount of oil into a baggie and allow the filter element to soak--I'll also toss a little bit of oil into the canister itself. Not for any meaningful reason other than peace of mind.

Whatever helps us sleep better at night, I guess.

 

[antonmnster]

I'm prefill when I can, but I'm not obsessive about it.

I certainly pre-fill my diesel filters. Getting air into the IP is a real pain.

 

[Danh]

I don't pre fill for three reasons: I doubt it really matters, it usually creates a mess and it results in unfiltered oil circulating through the engine for few seconds. Instead, I install the filter dry and "pre fill" it by cranking the engine for a few seconds with the accelerator floored. On a a fuel-injected car this shuts off the flow of gas so the engine doesn't start, but it does fill the filter under low-stress conditions. Start-up clatter is much reduced.

At the end of the day I really doubt any of this matters for a typical passenger car.

 

[Kiwi_ME]

I pre-fill because my knowledge of tribology gained professionally as an engineer tells me that sending a slug of air through the oil system is never a good thing while bearings are turning. The load while cranking with WOT is not that insignificant and the low speed makes the oil film even thinner.