U Dont Need To Prefill Oil Filter..Scotty Kilmer

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I agree, unless specified its probably fine NOT to pre fill. I do anytime it makes sense by filter orientation because it gives me the warm and fuzzies.

That guys voice is very hard to listen to sometimes, the start of his videos is downright agonizing. Stop yelling at me old man!
 
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Given that Stinky Peterson (RIP) posted a whole bunch of VOAs with particle counts, there is no way I'd be putting those contaminants on the clean side of the filter intentionally.

As to the premise that you "don't need" to prefill, that's exactly correct unless your OEM particularly recommends it as a part of the service schedule.
 
On my 1mzfe I can't pre-fill anyway, since the filter is pointing down 35 degrees and most all the oil would fall out when I screw the can in.
 
Originally Posted By: Shannow
Given that Stinky Peterson (RIP) posted a whole bunch of VOAs with particle counts, there is no way I'd be putting those contaminants on the clean side of the filter intentionally.
Except the oil filter will be in bypass until there is enough oil on both sides of the filter to give the proper pressure differential for the bypass valve to close.
 
Originally Posted By: CT8
Originally Posted By: Shannow
Given that Stinky Peterson (RIP) posted a whole bunch of VOAs with particle counts, there is no way I'd be putting those contaminants on the clean side of the filter intentionally.
Except the oil filter will be in bypass until there is enough oil on both sides of the filter to give the proper pressure differential for the bypass valve to close.


No, with air on either side, and even when the oil gets there, the bypass will be closed.
 
In general he is right about this. There are applications where it could be me necessary to pre fill a filter. In one of his videos he says not to worry about placing a support under a car with only a jack holding it up. Now that is downright stupid. I couldn't believe what I was seeing and listening to when he stated that. Many people have died as a result of a hydraulic jack giving way..
 
Originally Posted By: Chris142
He is mostly a hack


Yep. All the serious youtube mechanics constantly make fun of the guy.
 
"Most cars are bypass systems and oil doesn't go thru the filter to fill the system"....what is he talking about?!!!

Every car is a full flow system and bypassed only when filter obstructed enough to initiate "bypass".
 
This is one of the few things Scotty Kilmer has gotten right. I don't pre-fill my filters and... drum roll... I don't oil the o-ring! OMG!
 
Empty oil filter vs. "potential" contaminants that will be filtered out the first time around the system? Probably not a huge difference. I'll go with the empty filter as being slightly more harmful...on those vehicles where you can pre-fill (ie vertical filter with discharge oriented up).

The contaminant I'd be most leery of would be an oil bottle foil seal remnant or junk from the oil jug bottom getting into the discharge of the oil filter. Simply fill from the outside of the filter rather than the center hole (clean side fill). Fwiw, those going 2X and 3X OCI's on the same filter have the potential to send junk into the engine when/if the filter media tears. Some manufacturers like Cummins have in the past have recommended pre-filling. I guess if your OEM states NOT to pre-fill, then don't. If not mentioned, do what you prefer. No doubt that cars or trucks that don't have vertical filters have survived just fine on dry fills. It doesn't mean they didn't experience more wear than the ones that pre-filled. Back to the argument that if it doesn't blow up, it must be the best way.
 
I believe the only folks worrying about prefilling an oil filter are on this board.
 
Originally Posted By: ammolab
"Most cars are bypass systems and oil doesn't go thru the filter to fill the system"....what is he talking about?!!!

Every car is a full flow system and bypassed only when filter obstructed enough to initiate "bypass".


Some cars have internal bypass valves built into the oil pump in addition to the oil filter. The old Ford 3.8 V6 motors used to be famous for this valve binding up and staying in bypass.
 
Originally Posted By: 69GTX
Empty oil filter vs. "potential" contaminants that will be filtered out the first time around the system? Probably not a huge difference. I'll go with the empty filter as being slightly more harmful...on those vehicles where you can pre-fill (ie vertical filter with discharge oriented up).


37542143.Mobil10W40.jpg


Per this analysis, a cup full of oil put in on the clean side has added 13,500 25um and up particles that "may" be additives.
 
Originally Posted By: ammolab
"Most cars are bypass systems and oil doesn't go thru the filter to fill the system"....what is he talking about?!!!

Every car is a full flow system and bypassed only when filter obstructed enough to initiate "bypass".

My dad's '96 Buick Regal Custom spec'ed the AC PF47 filter, which had no bypass in the filter. There's a separate bypass valve that can be replaced.

https://www.amazon.com/ACDelco-25014006-Professional-Engine-Filter/dp/B000EPT4U8

71snVDomslL._SX355_.jpg


"Most cars" might be an overstatement though.
 
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