Never Prefill oil filters!

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Originally Posted by Pinoak
[You'd love the filter for my car. Not only does it come sealed in plastic, but they actually test it on a rig that pumps oil through it and cap the base end with a hard plastic cover before bagging it.


What filter is that?[/quote]

Maserati/Purflux filter for my GT
 
Originally Posted by CT8
Originally Posted by DoubleWasp
Originally Posted by CT8

The bypass valve operates by the pressure differential between the unfiltered side of the filter element and the filtered side. If the oil filter is empty or the oil passages are empty the bypass valve will remain open until the oil pressure stabilizes with oil pressure on both sides of the element the bypass will "close"


Ummmm........what?

Until the oil travels far enough to encounter the resistance of the engine, how do you imagine the oil to be under much pressure at all? Empty cavities of air don't present a lot of resistance.
You are telling us the oil filter element doesn't cause a resistance to flow to the engine oil? What then would be the pressure differential between the oil on the dirty side of the filter element and the air on the clean side of the oil filter element .


Until an oil filter fills to the top of the media, it is displacing air through the filter media. Little resistance at all.
 
So disable the ignition and fuel injection put the oil filter in dry and crank the engine until you get oil pressure. Unless the engine has not been started for a while should be ok. But that is step one in a oil change, warm up the engine.
 
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Catapiller has a warning about prefilling oil filters. Here is an example why.
https://www.turbodieselregister.com...-can-be-dangerous-to-your-engine.211771/

It is not that the oil itself is the issue, that little foil seal has caused the damage. I have heard of other instances that a mechanic has found that small foil piece in a oil passageway and could not explain how that got in the engine with a oil filter. Wonder if a coffee filter on a funnel would work.

I thought this subject was a joke until I started to dig into it.
 
Originally Posted by FordBroncoVWJeta
What about the oil you put in? Isn't it unfiltered?

Exactly my thoughts. So it's OK to pour oil from the jug directly into the engine. But if you pour oil into the new filter, it's a real problem!
Good grief, where do these myths come from?
 
All I've been doing is priming the filter and dumping the gallon jugs into the sump after ensuring there's no foil on the openings.
Waiting for my various engines to blow up, but hasn't happened yet.
 
Originally Posted by CR94
182 now posts about a practice never shown to have any significant effect, either positive or negative!


Exactly who would put the money into testing on this subject? Nobody stands to gain any money based on the outcome of the testing that I can think of?
 
Originally Posted by DGXR
Originally Posted by FordBroncoVWJeta
What about the oil you put in? Isn't it unfiltered?

Exactly my thoughts. So it's OK to pour oil from the jug directly into the engine. But if you pour oil into the new filter, it's a real problem!
Good grief, where do these myths come from?


I'm not sure if you read enough of the posts to understand the reasoning behind this argument... basically all of the oil you pour into the oil filler (at least in my cars case) goes right to the pan and gets pumped into the filter before it gets to any bearings. I never understood this before, now I'm on the fence about pre filling or not.
 
Originally Posted by CR94
182 now posts about a practice never shown to have any significant effect, either positive or negative!




Yep and twenty seconds after you start the engine all that oil is filtered anyway.

I fill my filters out of habit but I am starting to realize that today's oil pumps work a lot faster and coupled with thinner oils and smaller filters makes this a moot point. This is not your old Chrysler with 10w40 and a filter that holds a quart in itself.
 
Originally Posted by PimTac
Originally Posted by CR94
182 now posts about a practice never shown to have any significant effect, either positive or negative!




Yep and twenty seconds after you start the engine all that oil is filtered anyway.

I fill my filters out of habit but I am starting to realize that today's oil pumps work a lot faster and coupled with thinner oils and smaller filters makes this a moot point. This is not your old Chrysler with 10w40 and a filter that holds a quart in itself.



Great points PimTac ^^^^^^^^
 
Originally Posted by bbhero
Originally Posted by PimTac
Originally Posted by CR94
182 now posts about a practice never shown to have any significant effect, either positive or negative!




Yep and twenty seconds after you start the engine all that oil is filtered anyway.

I fill my filters out of habit but I am starting to realize that today's oil pumps work a lot faster and coupled with thinner oils and smaller filters makes this a moot point. This is not your old Chrysler with 10w40 and a filter that holds a quart in itself.



Great points PimTac ^^^^^^^^


Except that the debris that you put on the CLEAN side of the filter is straight into your galleries and areas of minimum oil film thickness (tenths of microns) before they make it to the sump...versus just putting them in the sump to be filtered.

(Oh, that and the foil, or the silver fish in the bottling plant)
 
Originally Posted by PimTac
I fill my filters out of habit but I am starting to realize that today's oil pumps work a lot faster and coupled with thinner oils and smaller filters makes this a moot point. This is not your old Chrysler with 10w40 and a filter that holds a quart in itself.


That old Chrysler had a positive displacement oil pump just like cars of today. A PD oil pump doesn't care if it's 0W-20 or 20W-50, the volume of oil per revolution going out the pump is the same.
 
Originally Posted by ZeeOSix
Originally Posted by PimTac
I fill my filters out of habit but I am starting to realize that today's oil pumps work a lot faster and coupled with thinner oils and smaller filters makes this a moot point. This is not your old Chrysler with 10w40 and a filter that holds a quart in itself.


That old Chrysler had a positive displacement oil pump just like cars of today. A PD oil pump doesn't care if it's 0W-20 or 20W-50, the volume of oil per revolution going out the pump is the same.


Was just thinking, my 1983 small block Chevy takes about 2-3 seconds for the oil light to go out after an oil change if I don't pre fill the filter. I don't think I've noticed that modern vehicles did any faster than that when I've changed the oil on them in the quick lube. I always watched for the light to go out or gauge to register oil pressure before checking for leaks after start up. So I'm not sure where this person "realized" that modern pumps are faster?
 
We consider it standard practice to pre-fill oil filters at work. A Cat C7 engine won't even start if you don't pre-fill the filter. (HEUI injection).

I don't, however, pre-fill oil filters at home. All the cars in the driveway have horizontally mounted filters, it would be a horrible mess.

The one exception is the Torino. I use an oversized filter on it, it holds over a quart. It would take to long (in my opinion) to build oil pressure without pre-filling. Different practices for different applications.
 
Originally Posted by Shannow
...Except that the debris that you put on the CLEAN side of the filter is straight into your galleries and areas of minimum oil film thickness (tenths of microns) before they make it to the sump...versus just putting them in the sump to be filtered.

(Oh, that and the foil, or the silver fish in the bottling plant)
This is about pre-filling with OIL, not with random trash.
 
Originally Posted by 69Torino
I don't, however, pre-fill oil filters at home. All the cars in the driveway have horizontally mounted filters, it would be a horrible mess.


On a horizontal filter you can pre-fill it to the point where the oil will not spill out the center hole when it's being installed. The horizontal filters I've prefilled that's been about 1/2 full before it will spill out while installing the filter.
 
It makes no difference to the engine.
Just more bee sss around here.
You guys need to worry about something important.
 
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