Prefilling Oil Filters - Necessary?

Messages
55
Location
AL
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!(y)
 
Messages
36
Location
GA
Horizontal filters are installed empty. I make enough of a mess as it is. If it is a vertical filter, I fill it out of habit. The exception is my 2016 Ford Focus. If I hold the accelerator pedal to the floor and turn the key it will turn the engine over for it's predetermined amount of time without starting it. It's not as messy and it does the job.
 
Messages
1,178
Location
Ontario, Canada
Horizontal filters are installed empty. I make enough of a mess as it is. If it is a vertical filter, I fill it out of habit. The exception is my 2016 Ford Focus. If I hold the accelerator pedal to the floor and turn the key it will turn the engine over for it's predetermined amount of time without starting it. It's not as messy and it does the job.
As long as the vertical screws UP if it screws down as in MB for example, that wouldn't work ;) I never prefill, nor have I seen tech do it these days. It used to be recommended in the past (more years than I care to remember)
 
Messages
801
Location
Saint Nazianz, WI
My Hyundai GDI engine (Gamma GF4D) has the oil filter mounted vertically, dome end down, and it is recommended to prefill a new filter before installation. I just did this last week and I did not find it at all difficult to do with the car on ramps while I was laying on my back.
 
Messages
141
After being on this site, if it is convenient I will do it, but for the 60 years before that I never did it, and so far as I know it never caused a problem. I always used it as a judge of the condition of the rod bearings are in the engine. No knock before oil pressure comes up, good bearings. LOL
 
Messages
15,847
Location
...
I do it out of habit if the filter placement let’s me but my current filter holds less than a cup of coffee so this last time I didn’t do it.

It’s a old habit from the days of large filters. If you still have a large one then go ahead. Tiny filters can be skipped.
 
Messages
323
Location
D-FW, Texas
I remember reading a thread some time ago where engine failures were attributed to foreign objects getting introduced during the filter pre-fill. IIRC, it was something like bits of foil from the bottle seal getting into the bearing journals. Someone said the filter the oil through a paint paper filter.
 
Messages
15,847
Location
...
I remember reading a thread some time ago where engine failures were attributed to foreign objects getting introduced during the filter pre-fill. IIRC, it was something like bits of foil from the bottle seal getting into the bearing journals. Someone said the filter the oil through a paint paper filter.


That sounds like careless work to me. Those same bits of foil would end in the crankcase anyway.

A moment of diligence is all that is needed to wipe the jug down of dust or any dirt particles. I use a small knife to cut the foil seal unless it’s Valvoline which has a pull tab ring.
 
Messages
25,786
Location
PNW
I do pre-fill as much as possible ... even if the filter mounts vertical with base down, then I just soak the media as much as possible to the point where no mess is made when installing the filter.
 
Messages
57
Location
Ontario Canada
I had never heard of this before joining the forum here. My filter hangs down not at a perfect 90 degree vertical, but more like 75 deg. First time I tried it, I filled it up too high and had a little dribbling of oil. Next time, I filled it about half way and no spilling. Main difference I noticed was that oil light would appear for about 5 seconds with no prefilling, but with filling filter half way, the light only stayed on maybe 1 second. Will it make any meaningful difference over the life of the engine? I'm not sure, but its not difficult to do and what the heck, it makes me feel like I'm helping; so there's that :rolleyes::unsure:
 
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Messages
1,480
Location
USA
I wonder if all modern fuel injection cars will turn over without starting with gas floored. Non hybridized of course. :D
 
Messages
1,173
Caterpillar has recommended for many years now to NOT prefill filters. Their reasoning is they’ve seen engines and other components damaged by prefilling filters. New oil can have some level of contamination in it and by prefilling the filter you run the risk of those contaminates circulating through the bearings
 
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