good reason to NOT prefill your oil filter

chillinn

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When I still had a gas vehicle I changed my oil every 2500 miles or so. Oil is cheap and it's easy to change
I have heard a number of "oil leaked out entirely" stories in the last decade, along the likes of "drove 1000 miles with no oil," that I suspect contemporary oil is so good, even drained the engine will still be lubricated from residual oil sticking to the internals and won't overheat under highway speed limit conditons as long as there's water and the pump works, but it can't be good for the engine.
 

bykfixer

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Does anyone here run Royal Purple?
It's supposedly the Hi Cri of motor oils.
My (now retired) boss uses it in his 63 Pontiacs and other special edition cars of that era like a 63 Impala Chevy only made 14 of with the motor/tranny seat combo he has.
He raced Pontiacs in 63/64 at NASCAR short tracks and for years restored models of Chevy's and Fords once raced on Sundays. He turned his attention to Pontiacs in the last few years. There was a Tempest that wiped the floor versus other cars at Daytona including the Vette.

He does not pre-soak his oil filters.
Needless to say the engines don't run very often or for extended periods but he has a 63 vette and 63 Ford he does drive on occssion for charity events and such. The vette was his first car and he still has it. It's been restored thrice. The last time it went from white with red seats to what I call silver but he says is Corvette blue with white seats. The Ford is black with red seats.
 
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The Hawk

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I have been changing the oil in my cars for about 50 years. I never pre filled the oil filter. So far, so good.
 

bubbatime

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I have over 10,000 post on the oil forum. I've studied and been fascinated with tribology for decades. I know a bit about motor oils.

What's in the bottom of your oil container is some of the additive package falling out of suspension. Most oil companies advise to use motor oil within 2 years or so. None of that gook will damage your engine.

Some guy tried to make this argument on the oil forum not to pour oil into the filter and prefill the oil filter because the oil "was non filtered" and his argument got tore to shreds, , rightfully so. You don't filter the clean oil straight out of the jug before dumping it into your engine.

You are overthinking a non issue. Yes keep prefilling your oil filters. Or don't. It won't make a difference.

I use my oil filters for two oil change intervals. I use filters designed for 20,000 miles of use that are built to handle the longer intervals. Plus filters get better the longer you use them. They filter out smaller particulates the longer they are in use (up until a point) I've done this for over a million plus miles. It saves on cost plus makes the second oil change very fast and a little cleaner too.
 

turbodog

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Well do what you want to do. I've seen more than just additive package in the bottom of new oil containers: flakes of metal/etc. Overall takeaway is also that the large center "fill hole" is actually the exit/downstream/unfiltered hole.
 
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Stress_Test

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Well do what you want to do. I've seen more than just additive package in the bottom of new oil containers: flakes of metal/etc. Overall takeaway is also that the large center "fill hole" is actually the exit/downstream/unfiltered hole.

Doing a visual inspection of anything you're about to install / pour into a vehicle is good practice anyway. Does anyone here inspect the oil filter itself?? I do. Many years ago I had bought a Mobil 1 filter and discovered it had RUST on the inside surfaces. Before I buy a filter, I take it out of the box and look at the threads, check for debris, corrosion, etc.

On another note.... it occurred to me that in all the years I've spent reading about cars, I've never seen an actual plumbing schematic for the oil system from pan to pump to filter to block etc. Has anyone seen an actual diagram that confirms the direction of oil flow?? I wonder if it might be different on some engines...

Only relevant info I remember is that apparently some engines will have a check valve of sorts (in the pump?) which, if the oil filter gets too clogged, will bypass the filter entirely. The idea being that it's better to send dirty oil through the engine as opposed to starving the engine of oil flow due to a clogged filter.
 

turbodog

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... I've never seen an actual plumbing schematic for the oil system from pan to pump to filter to block etc. Has anyone seen an actual diagram that confirms the direction of oil flow?? I wonder if it might be different on some engines...
...

Pickup tube screen (large chunks), pickup tube, pump, filter, and then to engine. From all the engines I've ever seen, either in diagram or cracked open, this has always been the same.

After the filter... mileages may vary on the path at that point.

You want oil flow through the filter from 'outside' to 'inside'. This compresses the filter media, helping hold it in place. Otherwise, the pressure tries to expand it, tearing it apart. Also, due to the angle of the pleats, this exposes a larger surface area to filter the oil. This means the large center hole is an exit/outflow.
 

orbital

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+

Talking with a buddy today, the subject was his work & a large diesel motor. His co-worker needed a quick how to on installing the fuel filter.
'couldn't be easier, fill the filter, lube the gasket and screw it on'
..immediately thought of this thread & asked if he pre fills his oil filters too.
He said Yes
I said there could be excess back pressure ect.. he said 'well, is it before or after the pump...'

There was no way I'm about to dent a friendship over prefilling a filter or not, so I left it alone.
 
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Might have asked him, innocently, which way the oil flows through the filter, spotlighting the issue for him without pretext.

What did you not understand about the following?
+

Talking with a buddy today, …..

There was no way I'm about to dent a friendship over prefilling a filter or not, so I left it alone.
 
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