The TRUTH about PRE-FILLING Oil Filters... ACTUAL SCIENCE - Freedom Worx

[Brain75]

with the filter primed it was about 2 seconds, with the filter unprimed he said 5, I counted to 9...

 

[Brain75]

I remembered it well enough I could find timestamps real quick...
filter #1 (primed) is 14:58 give or take and it looks like 2 3/4 seconds to start moving and 4 seconds to reach full pressure
filter #26 (unprimed) at 21:32 give or take it looks like it took 6 seconds to start moving and 9 seconds to reach full pressure
and I felt the needle moved much slower.


... but again counting mississ in my head, I tend to be just a tiny little bit fast.

 

[Bill]

@Brain75
This guy is only slightly more scientific than someone hacksawing open a used filter in their barn and saying look what I found. Slightly being the result of (A) not using a hacksaw in the barn, and (B) actually sending the samples off for analysis.

Those videos always amuse me. Opening a filter, counting the pleats, and checking the weight of the components in the filter isn't going to tell you much more than how many pleats it has and how much the filter weighs. A real test would involve testing the filter's ability to filter particulates down to a given size and if the bypass valve opens when it should. Maybe see if the filter lives up the its advertised lifespan.

 

[Brain75]

I haven't said what I do or how I feel about it and here's the big reveal.
Yes I do prime mine on the one and only where the filter is vertical, I figure if the motor will last 300k mi. without it primed and I can make it 350k mi. by priming it why not give it the extra love... It doesn't cost me a penny to do it. The first thing to go out like he said is gonna be rings or something else, not your bearings. I'm probably the only guy I have ever heard of that pulled a motor because of bearing wear. I've never had a motor that I wore out myself (the one and only I pulled with zero psi oil pressure was about 2k miles after buying it from someone else, and that whole 2k was spent chasing low oil pressure and learning about flatheads.)


All my cars have gotten crunched by some idiot except my first one, that had total meltdown worn out failure (I blew up the motor, put a new one in and wore everything out - I was 16-20yr and drove a ton of miles hard as hell). Since almost nothing lasts long enough to wear out I can't argue it is worth it or not and don't see a point in planting a flag and getting up in arms about it.

 

[JoshT]

I haven't said what I do or how I feel about it and here's the big reveal.
Yes I do prime mine on the one and only where the filter is vertical, I figure if the motor will last 300k mi. without it primed and I can make it 350k mi. by priming it why not give it the extra love... It doesn't cost me a penny to do it. The first thing to go out like he said is gonna be rings or something else, not your bearings. I'm probably the only guy I have ever heard of that pulled a motor because of bearing wear. I've never had a motor that I wore out myself (the one and only I pulled with zero psi oil pressure was about 2k miles after buying it from someone else, and that whole 2k was spent chasing low oil pressure and learning about flatheads.)


All my cars have gotten crunched by some idiot except my first one, that had total meltdown worn out failure (I blew up the motor, put a new one in and wore everything out - I was 16-20yr and drove a ton of miles hard as hell). Since almost nothing lasts long enough to wear out I can't argue it is worth it or not and don't see a point in planting a flag and getting up in arms about it.

You're not the only one. That's what was wrong with the first 5.0L I put in my 99. Good compression, cylinders looked good, low oil pressure as a result of worn bearings. Not zero oil pressure, but low enough that I didn't trust it to get away from home.

Pretty certain that is also the problem with the 360 FE in my '68 F-100. Since I was a kid it has had terrible oil pressure. Not as low as that 5.0, but terrible. It has also run like a champ though. Even when I revived it after dad parked it for 12 years the story was the same. Since I wasn't prepared to rebuild the engine at the time and needed to fix an oil pan leak, I popped in a high volume oil pump and used a heavier weight oil. Might be a bandaid, but it's maintaining acceptable oil pressure now.

 

[Curious Hound]

We were told to always prefill oil filters in autoshop back in a community college engine course. I mentioned I couldn't do that with my car. The dude teaching the course said, "sure you can. we can put your car on a lift tomorrow and I'll show the class how it's done." So, the next day we put my car on a lift. He had me remove the old filter while he was explaining stuff about engine lubrication to everyone else. Then he asked me if it was ready for the new filter. I said, "yep!" He then filled the new filter, walked under my car and stared at the filter mounting surface, then said, "some cars have filters that mount sideways, In this case you can't prefill the filter because the oil will run out when you are installing it."

I still don't bother prefilling oil filters because it takes about two seconds for the oil pressure to come back after an oil change.

That's where I'm at on this. You can't do it on a 3.0l. I guess I could do it for the powerstroke. But I probably won't. They're always full when I pull the old one off. So it must be working OK without prefilling.

 

[19Walt93]

Fleet mechanic here…

Don’t bother prefilling the filter.

We had about 50 or so E250/E350 vans in our fleet (were down to about 15 due to rust). Over time a few of them had the oil drain plug nut inside the steel oil pan (the V8 a have steel pans, the V6 a have aluminum pans) break loose. They will still seal up and not leak any oil, but you can’t remove the plug.
At 120K miles, we are not going to pull an engine out of a van just to replace the oil pan. So here’s the dilemma… how do you change the oil without being able to remove the drain plug?

I know you’re all thinking simple… you remove the oil filter and crank the engine until all the oil is pumped out. So that’s the way we changed the oil on at least 3 vans for years. Not one of them was auctioned off due to a bad engine. 2 of them went to auction due to rust issues, and 1 is still in the fleet 8 years later.
If we can use the oil pump to pump the engine dry and have the engine last, then a few seconds of low oil volume isn’t going to hurt anything.

Don't they still sell slightly oversized plugs that cut their own threads?

 

[19Walt93]

I didn't watch the video, with all those Fram filters I just assumed he doesn't know what he's talking about. I prefill my filters because it takes seconds, might help a little, and can't hurt. The remote filter on my Ranger and the filter on my Escape hang straight down. The Mustang filter is at an angle so I can only fill it a little over half.

 

[sgtsandman]

Great discussion and that was what I was hoping for when I posted this.

The results of the video didn't surprise me considering how it was done but I do believe his overall premise at the end of the video was correct. Piston wall and ring wear will take out an engine before bearing wear will most of the time.

I do prefill my filters just because it doesn't hurt anything. Granted, the filter on the 2019 only gets filled about half way because it mounts horizontally rather than vertically. Enough to soak the media and get some oil in there. It's a small filter, so it isn't like it takes that long to fill anyway.

The only time I've ever replaced an engine was when the head gasket failed and the resulting steam pressure from coolant entering in a hot cylinder destroyed a couple of pistons.

 

[sgtsandman]

I don't have 40 minutes. Condensed printed version?

Cliff note version, prefilling the oil filter doesn't make enough of a difference to matter. Cylinder wall and piston ring wear will take out an engine before bearing wear will in most cases. Something a prefilled filter or not is not going to effect.

 

[Snoranger]

Don't they still sell slightly oversized plugs that cut their own threads?

Yes but the Econoline oil pan is stamped steel with a “nut” welded inside. When that weld breaks and the steel piece that resembles a nut is no longer attached, the pan isnt really thick enough to hold up to repeatedly removing and installing a thread cutting drain plug. If it just stripped the threads, that’s a completely different story. So, you just paint the bottom of the pan red and everyone in the shop knows what that means.

 

[Bill]

Don't they still sell slightly oversized plugs that cut their own threads?

I think it's an insert you thread into the damaged hole and you insert a smaller drain plug into it.

 

[Shran]

I pre-fill them when I can and especially my V8 swapped truck with the remote oil filter. There is a lot of oil in the hoses that go to it.

I had a 2.3 that would tick really bad for about 10 seconds if I didn't pre-fill the filter. Filter full = no noise.

 

[85_Ranger4x4]

I remembered it well enough I could find timestamps real quick...
filter #1 (primed) is 14:58 give or take and it looks like 2 3/4 seconds to start moving and 4 seconds to reach full pressure
filter #26 (unprimed) at 21:32 give or take it looks like it took 6 seconds to start moving and 9 seconds to reach full pressure
and I felt the needle moved much slower.


... but again counting mississ in my head, I tend to be just a tiny little bit fast.

We are dealing with gauges calibrated by GM 40 years ago, not Texas Instruments last week...

 

[Brain75]

I do have a horror story to add... my flathead in the process of diagnosing the zero psi oil pressure I went through everything step by step and posted to the FTE forum over and over.. well when I pulled half the oil pump out it piddled 1 tsp of oil and I thought nothing of it, reassembled it all after cleaning and checking tolerances and the wail it made would make a banshee blush. Tech note: if you ever pull the oil pump, prime it with vasaline in those old flathead girls.