Never Prefill oil filters!

[Mr Nice]

Originally Posted by Malo83
Always prefill my 2qt filters with 1qt of oil before spinning on the engine.

What type of engine uses 2 qt oil filter?

Big rig 18 wheeler engine ?

 

[PimTac]

"I have no problem pre-filling oil filters. I dont shake the bottle just in case any heavy stuff has settled out in the bottle. "


I hadn't heard this one before. Should we shake or not shake?

I can start another dumb thread.

 

[ZeeOSix]

Originally Posted by PimTac

"I have no problem pre-filling oil filters. I dont shake the bottle just in case any heavy stuff has settled out in the bottle. "
I hadn't heard this one before. Should we shake or not shake?

I can start another dumb thread.


I'm sure you've seen the many threads in the PC oil forum about sediments in the bottom of oil jugs. If not, start reading more forms on BITOG.

 

[PimTac]

I always shake. I paid for those additives and I want them to be mixed with the oil.

 

[krismoriah72]

Originally Posted by ZeeOSix
Originally Posted by PimTac

"I have no problem pre-filling oil filters. I dont shake the bottle just in case any heavy stuff has settled out in the bottle. "
I hadn't heard this one before. Should we shake or not shake?

I can start another dumb thread.


I'm sure you've seen the many threads in the PC oil forum about sediments in the bottom of oil jugs. If not, start reading more forms on BITOG.

I have seen the many threads about 'sediments'.. and have seen those little pools in the bottoms of jugs myself.. i am somewhat convinced its additive fallout. Someone needs to scrape the bottom of the jug and send it off.. Perhaps its Calcium and or Zinc.

 

[ZeeOSix]

Originally Posted by PimTac
I always shake. I paid for those additives and I want them to be mixed with the oil.


My point was shake after pre-filling the filter, just in case any other contamination/debris settles out.

 

[JC1]

Originally Posted by ZeeOSix
Originally Posted by IndyFan
A guy posts something stupid and we get 5 pages in his thread. Love da internet!


In only 4-1/2 hours.

It's a slow TV day.

I never used to prefill filters. Now I do and oil the pleats on the catridge filters. On the civic I let the pleats soak overnight, if I remember and then dump the oil back into the container (insert cringe here), since it's mounted on the side of the block.

We all know stealerhips and quick lubes wouldn't do that. Heck they don't even let all of the oil out of the sump. Lol

 

[Kestas]

Originally Posted by Linctex
Originally Posted by Zee09
What do you do if you have no oil filter?

So do many aircraft engines.

Maybe has something to do with not interfering with the magnetic chip detector?

 

[Linctex]

Originally Posted by ZeeOSix
Originally Posted by PimTac
I always shake. I paid for those additives and I want them to be mixed with the oil.

My point was shake after pre-filling the filter, just in case any other contamination/debris settles out.


That makes sense - - but I still don't worry about "contaminates" in my oil!

 

[WellOiled]

When you purchase an airplane, the oil filter, mount and plumbing cost extra. To save weight, some buy the plane without the filter. The service interval is shorter without the filter. So maintenance is more expensive.

 

[Linctex]

Originally Posted by Kestas
Originally Posted by Linctex
Originally Posted by Zee09
What do you do if you have no oil filter?

So do many aircraft engines.

Maybe has something to do with not interfering with the magnetic chip detector?


No chip detectors in the piston engines that I am thinking about.
Turbine engines usually have them, though.

Now, chip detectors in Helicopter main rotor gearbox and tail rotor gearbox - those also do exist.
I got some stories!

 

[CT8]

Originally Posted by ZeeOSix
Originally Posted by CT8
Originally Posted by ZeeOSix
Originally Posted by CT8
The oil filter will be in bypass until the oil pressure builds.

Why? Oil pressure "building" has nothing to do with the operation of the bypass valve.

I guess you are the expert on how an oil filter bypass works,


Please explain why you think a filter bypass opens up until oil pressure is achieved. I just want to know why you think that.

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"

 

[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.

 

[ZeeOSix]

Originally Posted by CT8
Originally Posted by ZeeOSix
Please explain why you think a filter bypass opens up until oil pressure is achieved. I just want to know why you think that.

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"


The part in red doesn't work that way. Delta-p across the filter is only caused by the flow and viscosity of the oil. The bypass valve doesn't operate on oil pressure in any way, and it doesn't care if the filter is empty or full.

If you have X flow at 1 PSI or the same X flow at 60 PSI, the delta-p across the filter media is going to be the same. The filter being either empty or full, the bypass valve is going to be closed at start-up unless you have very thick cold oil and rev the engine way above idle instantly after a cold start. Too much viscosity + too much flow = more delta-p and maybe an open bypass valve, regardless of the operating pressure or if the filter is empty or full.

 

[DoubleWasp]

BTW, this topic is really dumb. What exactly are the chances that new engine oil is dirtier than dirty engine oil during a valid bypass event?

The induction of unfiltered oil is always a possibility. Pre filling a filter is no more risky than that.

 

[CR94]

Originally Posted by PimTac

"I have no problem pre-filling oil filters. I dont shake the bottle just in case any heavy stuff has settled out in the bottle. "
I hadn't heard this one before. Should we shake or not shake? ...I can start another dumb thread.
Shake AFTER you prefill the filter. That way, the purported abrasive particles in new oil won't wreck your engine upon start-up, yet the expensive additive sediment gets into the sump---then will eventually be either dissolved by heat and agitation, or captured by the filter.

 

[SubieRubyRoo]

ZeeOSix, yes I am aware of the minutiae that oil filters will trap some percentage particles smaller than the absolute rating... my point was to say that the extremely small particles like 3 microns just keep circulating- and a great majority of the particles >20 microns will be caught on the first pass thru a good filter, so there is little risk of real damage to the engine from the little bit you'd prefill the filter with.

 

[Pinoak]

Originally Posted by PimTac
I always shake. I paid for those additives and I want them to be mixed with the oil.

I shake but never more than 3 times.

 

[SubieRubyRoo]

Originally Posted by Pinoak
I shake but never more than 3 times.


If you shake it more than 3 times, you're just playing with it.

 

[StevieC]

If pre-filling an oil filter was important they would have a procedure for filter cartridges. Further the quick lube places don't do it and none of those engines suffer as a result.
OE's would have statements in the manuals if it was worthwhile as well.