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

[sgtsandman]

I found this video to be interesting and I liked the way it was presented.

 

[alwaysFlOoReD]

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

 

[racsan]

Very interesting. I myself have always pre-filled filters, probably still will. Just did a oil change today, the 1.5 turbo in the equinox.

 

[Bill]

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.

 

[Brain75]

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

Ultimately the end story is, when you change the oil after 1 minute of running and are constantly cleaning out the pan by washing it with new oil then the parts per million just keeps going down. So he didn't do a fair test - a fair test would have taken him 50 years with 1 vehicle or 1 year with 50 vehicles. He did however do about as closely controlled highly scientific well designed tests that can be done.

 

[Brain75]

And with a change from 10 parts per million to 7 or 7 to 4 the results were so tiny that could not be considered statistically meaningful.

 

[Brain75]

I am gonna throw something out, that also kinda nullifies his findings... high zinc oil (what he was using) leaves a zinc layer behind to sacrifice itself before pressure builds up - marketting hype and scientific tests say this.... Problem is high zinc oil ruins the cat converter, it is called "classic" and recommended for flat tappet engines for a reason, most of those predate cats. His test is only relevant for those who can or do run high zinc oil... since I have a cat I wont be running it in mine.

I do run different oil in my '48... pain in the ass to have 2 different oils, but it calls for straight 30 weight and a lot of guys run diesel 40w - they are a high volume low pressure system and believe it or not the old flathead engine still runs perfectly fine between 3-5 psi oil pressure. My first block that came from the PO would empty the whole pan out the filter housing in 2 seconds and it had LITERALLY zero psi reading on 3 gauges. (It uses a "toilet paper tube" style filter inside a housing - rare to even have a filter before the 60's.)

 

[Snoranger]

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.

 

[85_Ranger4x4]

I always prefill the one in my Ranger.

It is remote mounted and it makes the dipstick read a little more accurate when I get done with only whatever is in the hoses not accounted for. It isn't hard to do and I don't see any good reason not to do it.

Everything else I have is mounted open end down or is a cartridge... and is mounted on the engine.

 

[Rick W]

I always prefill the one in my Ranger.

It is remote mounted and it makes the dipstick read a little more accurate when I get done with only whatever is in the hoses not accounted for. It isn't hard to do and I don't see any good reason not to do it.

Everything else I have is mounted open end down or is a cartridge... and is mounted on the engine.

ditto, I don’t think it’s mandatory, but it certainly can’t hurt, so I pre-fell when it’s easy. When I can’t, sometimes I pull the coil wire, and crank the engine with no load until the oil pressure starts to wiggle.

Road Rangers has 300,000+, so any little trick is worth a few minutes to keep it going. The engine was replaced in the 87, so it only has about 45,000 miles. All the Lincoln’s are under 100. The F250 7.3, different animal….

My two cents….

 

[JoshT]

@Brain75 pretty much summed up my thoughts when I came across the video the other week. I'm not going to say that the test wasn't fair, he did give all the filters the same run time under as close to the same conditions as he could manage. IMO the established conditions could not provide an accurate result. Most bearings are made of multiple materials, as they wear the traces in the oil sample will gradually shift. The only way he could test accurately would be 50 years with one vehicle and regularly rotate between filled and not filled during the life of the test. Then repeat that test with several vehicles to establish repeatability of the results. Due to usage, material devciations, etc, the 50 vehicles for one year version would introduce too many variations to be an accurate test. You also couldn't do 25 filled, then 25 unfilled over an extended period like that due to material variations in the wear surfaces.

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.

Anyway, I'm not going to say filled or not. I fill. All my stuff is easy to pre-fill, it doesn't take much added effort, and I haven't been presented a good reason not to. I heard the guy's claim about introducing trash into the filter, but that's nonsense. Been prefilling lying in the dirt and grass for the last 20 years, it isn't difficult to keep the filter clean while you are pouring in oil and installing. If I had a vehicle with a horizontal or inverted filter, I wouldn't fill and wouldn't worry about it.

 

[Bill]

ditto, I don’t think it’s mandatory, but it certainly can’t hurt, so I pre-fell when it’s easy. When I can’t, sometimes I pull the coil wire, and crank the engine with no load until the oil pressure starts to wiggle.

Road Rangers has 300,000+, so any little trick is worth a few minutes to keep it going. The engine was replaced in the 87, so it only has about 45,000 miles. All the Lincoln’s are under 100. The F250 7.3, different animal….

My two cents….

Just start it up the next time you change the oil and watch how fast the oil pressure comes back. Also, watch the videos on youtube where people run engines without oil to see how long they last. They last quite a while at idle. Some of them have to be run at a high enough rpm to burn the oil out of the bearings before the engine self-destructs. Modern oil is that good.

 

[Brain75]

I will point out that his own video (he dropped the clock off the dash) and then said "it took about 5 seconds" - looked more like 9 to me counting mississippi's in my head

 

[Bill]

I will point out that his own video (he dropped the clock off the dash) and then said "it took about 5 seconds" - looked more like 9 to me counting mississippi's in my head

I don't think I've ever seen oil pressure take that long to come up. But, I've always used 5w20 or 5w30. He is using 15w40.

 

[SenorNoob]

Now I wanna put a stopwatch on mine next time I change it. It feels like a couple seconds...