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Some engine manufactors and people recommend pre-filling an engine oil filter with oil to prevent a "dry" start up. I personally feel that the risk of contaminates entering the system is of greater concern than a short period of no oil pressure till the filter fills.
What's the consensus of the experts?
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quote:
Originally posted by Wiley:
Some engine manufactors and people recommend pre-filling an engine oil filter with oil to prevent a "dry" start up. I personally feel that the risk of contaminates entering the system is of greater concern than a short period of no oil pressure till the filter fills.
What's the consensus of the experts?


Will any more contaminants enter the system this way than from pouring new oil into the oil filler opening? I realize the oil filler opening does not go to all the bearings but just drains to the sump, but I would think oil filters routinely (cold starts) run in bypass mode and so any contaminants would get into the system anyway. Also I would hope fresh oil in a sealed bottle would have minimal contaminants.
Let's do the opposite calculation. Let's assume an oil pump runs during idling speed. The flow rate is 3 L/min at this condition. Your camshafts are unlubed. You have ca. 1 Liter volume between pump, oilfilter and camshaft.

How many particles will I produce, if the camshaft is running 20 seconds without oil?

quote:
but I would think oil filters routinely (cold starts) run in bypass mode and so any contaminants would get into the system anyway.


Engines are more robust then you think. These few particles you are refering to do not hurt a good engine. Wink
Agree. My point is that the chance of contamination by prefilling the filter is slim to nothing. I always prefill my filters.

As for engines being robust, I heard that you actually don't need a filter after the first few oil changes where you are filtering out machining debris and casting sand particles that remain from manufacture.

I recently ran a 4400 mile oil interval on my motorhome with a filter having an efficency of 68 percent at 30 microns (this would make some cringe at thoughts of contaminants getting through). The used oil analysis was outstanding (and the manufacturer recommends 3000 mile oil change). But this filter flows 15.85 gallons per minute, nearly twice that of a Purolator filter (which I believe filters much more finely). Anyway, the filter was a Fleetguard LF 697 and I may just go over to these all the time. I want a good flowing filter.
What led me to ask this question in the first place was finding a dead mouse in a brand new unopened one gallon jug of Chevron Delo 400. Might not have even caught it except it clogged my funnel. My experience has been where ever there are mice there are mouse turds, a perfect size for clogging cylinder oil nozzles.
I had always pre-filled filters prior to this.
Contacting Chevron about this they said there is always the potential for contamination as they don't manufacture the containers and they are shipped and stored without a lid.
Just wanting to find out if taking the contamination chance is a better choice than a dry start.
That is a freak incident! I guess you could get one of those funnels that have a fine mesh screen and use that to fill the filter and the crankcase.

Shipping the containers opened doesn't sound good. Hopefully wrapped in something else, or cleaned before filling. And to think I worry about a piece of the plastic ring or a bit of foil (on the foil sealed bottles) getting into the oil.
Start UP has esters (how much nobody knows) which are polar in nature and cling to metal. This is supposed to maintain a better coating of lube on the engine insides so that start up wear is reduced. I believe there is merit to it. I don't think much ester would be needed for this effect though. But Start Up is a bit pricy. I do wonder why nobody has developed an ester additive for start up protection. Seems like a good idea. Rislone has an additive called Winter Start which is synthetic oil of some sort, but does not appear to be ester as the MSDS says it is 75% "Mixture of Synthetic Refined Petroleum Base." They also have Rislone Upgrade which is 15-25% "Trimethylolpropane Ester." So a 15 oz bottle woudl give you about 3 oz of ester--not much.
quote:
As for engines being robust, I heard that you actually don't need a filter after the first few oil changes where you are filtering out machining debris and casting sand particles that remain from manufacture.


Yep, depending on how much sand is in your engine, this is true.

quote:
I recently ran a 4400 mile oil interval on my motorhome with a filter having an efficency of 68 percent at 30 microns


That's a bad efficiency.

quote:
But this filter flows 15.85 gallons per minute, nearly twice that of a Purolator filter
And this the effect of the bad filter efficiency. Filterfiness and pressure drop vs. flow rate build a simple equation.
But look at the good oil report with that "poor" oil filter:

Ford 1990 E350 Motorhome, 460 V8, 73767 miles. Valvoline Maxlife 10w30 @ 4355 miles. Oil was in the vehicle for two weeks in early May for a trip from Detroit MI to Glacier National Park MT and back. I ran it hard pushing 70 mph for several hunded miles at a time on the return. Bucking some severe winds on the way out. Even a couple 2nd gear hills on I-15 when bucking heavy winds. Makeup oil (including 8 oz overfill 1000 miles before the end) total 59 oz. Initial fill 6 and 2/3 qts. Adjusted for make up oil it is approx 3800 miles. MH weighs roughly 12,000 lbs loaded and the manual says to change the oil after 3000 miles.

Viscosity @ 100C: 10.32
SAE Grade: 10w30
Water: <0.5
Fuel: <0.5
Gycol: Not detected
Soot: 0.00

Posassium: <1
Vanadium: <1
Moly: <1
Magnesium: <1
Calcium 1513
Barium: <1
Phosphorus 709
Zinc 773
Antimony: <1
Titanium: <1
Silver: <1
Copper: 5
Lead: <1
Tin: 3
Aluminum: 4
Nickel: <1
Iron: 8
Chromium: <1
Cadmium: <1
Sodium: <1
Boron: 20
Silicon: 3

And oil pressure was approx the same as with other, more restrictive filters.
Can you name that study, I'll get it and then we talk again after my vacation.

As for the wear particles and the factory dirt....
Some manufactured engines can be quite dirty even for more then one oil change.

If you have a good airfilter, the oilfilter is not that important as one might think. I've seen an engine running in Saudi Arabia. It was running fine, even though the oilpan was filled with about 10 mm with fine dust particles in oil. The oilfilter was OK, but it was not capable of collecting this fine dirt. You could see that the piston and bearings where a little pre-damaged.

However, to use a good oilfilter as "back-up solution" can not be a mistake. Just in case... Wink
The oil filter on the 2.2 Ecotec motor in the 2003 and 2004 Chev Cavaliers rests on top of the motor inside a plastic cover. When changing the filter you remove the plastic cover and replace the paper element. It has no anti-drainback valve and therefore, is empty when you remove the plastic cover. I checked with GM and they advised that an anti-drainback valve on this motor is unnecessary because it's efficient oil pumping and distribution system provides instant oil pressure upon startup.

Therefore, you can't pre-fill these filters!
After reading the posts on this subject, it seems to me that the best course is to install the oil filter with as much oil in it as possible short of spilling oil all over the place. If the area in which the oil filter resides is dirty, taking a rag and wiping the worst of the dirt off seems to be a better solution than starting the engine with the oil filter empty. This is especially true with overhead cam engines with bearing surfaces a long way from the oil. It is also important with fuel injection because the engine starts very quickly and runs to a high RPM.
Well folks. I went to a Ashland Oil Company (Valvoline) mechanics seminar to learn about how oil reacted. This really opened my eyes. Show us at test conducted at 32 degree and with 30W oil. I took a engine running at approx. 1,000RPM almost a full minute to get oil up to the valve covers to lube the rockers and valves. Tells you something huh? Good quality oils will hold a pretty good film for some time before metal to metal contact. Some engines have there oil filter installed upside down also. Pretty hard to pre-fill them. Just install your filter and fire it up.
Question to you Callisa: Is the above about not needing a "good filter" your opinion or fact? Is this only for certain engines, specific conditions or other driving styles ? What about diesels with the new EGR systems ? I've done some reading on this and it appears this is something to raise tremendous concern from cradle to grave. Thanks in advance.
It is always important to have a good filter if for no other reason than that the filter will have higher quality construction including a better seal (Viton) which insures that oil flow will be sufficient under all conditions. Better quality filters will have a higher quality media that is sometimes wire-backed so it stays in place even when oil flow surges under hard acceleration. I prefer my CM filter because it never runs in bypass mode since it doesn't have a bypass valve.
quote:
Originally posted by Callisa:
Your cams must be really suffering in the winter during cold start. This bypass valve is important.
If your OEM requires you to use an oilfilter with bypass valve, you should use one.

Would he not also be putting undue stress on the oil pump, risking sheering the shaft on a very cold morning, and/or blowing out the filter canister or gasket and spilling all the oil on the ground to the demise of the engine?
quote:
Would he not also be putting undue stress on the oil pump, risking sheering the shaft on a very cold morning, and/or blowing out the filter canister or gasket and spilling all the oil on the ground to the demise of the engine?
No. SynLube is no harder to pump than is a 5W20 oil because when it's cold, it's the 5W rating that counts. I've been through 4 winters with this oil and without any problems at all. Well, maybe once when my four tires fell off their rims.

BTW, I had two winters with a Ford Zetec engine for which 5W20 was recommended. SynLube was perfect for this engine.

Honestly, lets remember that SynLube is made entirely of synthetic fluids and solids and its properties will be similar to Amsoil or Mobil 1 at the cold temperatures excepting, of course, that the dry lubricants are embossed into the bearing surfaces so even if all the oil drained to the pan (which we know doesn't happen because of synthetic oil's polar attraction to metal), the surfaces would still be protected long after a conventional lubricant would have failed.
Last edited by houckster
quote:
Question to you Callisa: Is the above about not needing a "good filter" your opinion or fact?

It's a fact. I improved an existing oilfilter two years ago and had to do some research before I started doing that. It was amazing to see what was left from some spin on oilfilter materials.

That CM Oilfilter design looks interesting. The product would be even more interesting for me if I could find a flow curve with a 5W-X oil flow rate vs pressure drop. Frown
There's absolutely no reason not to prefill the filter if it's possible to do so. Just make sure the area around the filter has been wiped down to be sure that no dirt falls on the filter when you're installing it.

A clarification on the oil filter quality question: You do need a good oil filter. Removal of contaminants is only part of the job a filter does. If the contention is that after a couple of oil changes, there's nothing for the oil to filter, I won't argue that point (although I remain skeptical, at least with dino oils) but the other part of the filter's job is to pass oil efficiently. Cheap filters are not as safe. I believe that the Fram oil filters are notorious for periods of engine oil starvation based on feedback I've seen on other enthusiast sites. Once I switched to the filters sold by SynLube, and then to the CM filter, I never had that problem again.

Good filters have a synthetic media that is wire-backed to keep the media in place and to permit long drain intervals since the media won't tear. When media pleats migrate against one another, backpressure goes up. They also have greater media area, higher quality gaskets and thicker, more burst resistant casings.

Like the oil, the filter is such a critical part of protecting an engine that it makes no sense to buy a cheap filter.
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