Warning: Prefilling An Oil Filter Can Be Dangerous To Your Engine

[HBarlow]

He was saying the pistons were damaged prior, to the cooling jets getting plugged, then the engine seized up. He had stated, that he had not seen one fail because of foil from an oil bottle seal.

I wouldn't put much trust in that technician. He sounds like a few I have talked with.

If you examine the filter and the mount it attaches to it is clear that the center of the oil filter has the large threaded opening that attaches to the filter mount. I'm no engineer but it seems logical that the oil pump would take a suction through the large threaded opening in the center of the oil filter and return oil throuugh the smaller diameter openings around the outer perimeter of the filter. Oil flows from outside to inside in the filter.

 

[HBarlow]

IRRC the newer trucks are using a pressure Switch... ... good or bad

Thanks for the answer. Does that mean the pressure switch simply reads oil pressure as pressure or no pressure and the ECM simulates a pressure reading? That's what the '01 reflash did.

 

[brods]

Just asking, were did you get this?

There is a diagram which confirms that in the factory service manual in the section: engine, 5. 9 diesel service information, lubrication, description. Also if you were to cut open a filter you'd see the media is only supported on the inside (the perforated metal tube you see when you look in a filter) so the flow has to be from the outside in or the paper media would be destroyed. If your still unconvinced I still have the disassembled filters from when I compared the Mopar brand to Fleetguard to confirm they were identical. I could snap a picture if you like.

If you don't prefill the oil filter and when you have filled the engine with fresh new oil, can you bump the starter a few times to fill the new oil filter? Same as we do to fill a new fuel filter.

Thats is a good question. The only place I could find specs on oil flow rate was here: 96-98 engine specs and it lists 20 GPM but no reference to at what rpm. Lets assume it is at or close to max rpms, say 3,000 and that the 3Gs pump the same as older motors. Since the oil pump is a positive displacement type the flow rate is directly tied to rpms. So 3,000 engine revolutions equals 20 gallons. Then 150 revolutions equals 1 gallon. So 38 revolutions equals 1 quart.



That means the engine will have to turn over about 38 times to pump 1 quart into the filter. Does not sound practical by bumping the starter. Even if the 20 gpm spec was at idle the engine would have to turn about 10 revolutions to pump a quart.



Just for the heck of it I emailed Cummins yesterday asking for an official position on pre-filling the oil filter. If and when I hear back I’ll post up.

 

[brods]

I wouldn't put much trust in that technician. He sounds like a few I have talked with.



If you examine the filter and the mount it attaches to it is clear that the center of the oil filter has the large threaded opening that attaches to the filter mount. I'm no engineer but it seems logical that the oil pump would take a suction through the large threaded opening in the center of the oil filter and return oil throuugh the smaller diameter openings around the outer perimeter of the filter. Oil flows from outside to inside in the filter.

The pump is upstream of the filter, meaning the pump pushes the oil through the filter, in through the outside small holes and out through the center threaded hole.

 

[opjohnny]

Interesting thread. I prefill the filter 3/4 full once it stops soaking the oil up. I also use a funnel with a small screen built into it. When you think about all the oil changes you make in 500k miles, if you drive it that long, each one of them is a chance to introduce something foreign in an engine that has tight tolerances.

John

 

[HBarlow]

The pump is upstream of the filter, meaning the pump pushes the oil through the filter, in through the outside small holes and out through the center threaded hole.

Thanks for an excellent explanation about crankcase oil flow rates and number of revolutions required in your other post and for setting me straight on where the filter is in relation to the oil pump.

I guess in my case, a little knowledge was dangerous. I accept your explanation, it makes perfect sense.

You're saying oil flows through the oil filter from outer chamber to center chamber and out of the oil filter center chamber back into the oil pan. That still means that any foreign object poured into or dropped into the center of the oil filter flows direct into the oil sump where the pump could pick it up and pump it straight into the cooling jet holes in the bottom of the pistons.

I think the caution about a small slivver of oil jug seal being unknowingly poured into the oil filter would still apply. I'd like to read the answer from Cummins when you receive it.

 

[brods]

Correction: Fleetguard LF16035 oil filter does not have internal bypass valve.

.....



You're saying oil flows through the oil filter from outer chamber to center chamber and out of the oil filter center chamber back into the oil pan. That still means that any foreign object poured into or dropped into the center of the oil filter flows direct into the oil sump where the pump could pick it up and pump it straight into the cooling jet holes in the bottom of the pistons.



I think the caution about a small slivver of oil jug seal being unknowingly poured into the oil filter would still apply. I'd like to read the answer from Cummins when you receive it.

Yes, but with a important correction. The oil flowing out of the filter goes directly into the block passages and to the turbo, then back to the pan. So the caution about the foil seal definitely applies!



Also keep in mind that there are two ways for dirty oil to bypass the oil filter element. First is the 50 psid bypass valve built in to the oil filter mount. Second is an internal bypass valve inside the oil filter itself. Maybe if Wayne (amsoilman) reads this he can chime in with at what pressure drop across the oil filter element the internal bypass typically kicks in. Anyhow, during cold starts when the oil is thick, unfiltered oil from the pan will bypass the filter element and flow directly into the engine until the oil warms up a bit. Therefore it is wise to keep any foreign material out of the engine oil. So again the caution about the foil seal applies.



Since the engine lasts a good long time even with this normal small amount of "dirty" bypass during cold starts, I would not worry at all about pouring unfiltered clean oil directly into the filter. Just make sure you can account for the entire foil seal and pour from a new jug where you are only tipping the jug to the side, not upside down. That way in the rare event there is something at the bottom of the jug it will stay there. And, of course, watch the oil closely for anything abnormal as you’re pouring it in.





Here is a decent description of how the oil filter works: All About Oil Filters



I checked with Fleetguard and they say their LF16035 StrataPore oil filter does not have an internal bypass valve. That means the only way to bypass the filter element with dirty oil is through the 50 psid bypass valve in the filter mount. Good news!

 

[AH64ID]

Yes, but with a important correction. The oil flowing out of the filter goes directly into the block passages and to the turbo, then back to the pan. So the caution about the foil seal definitely applies!



Also keep in mind that there are two ways for dirty oil to bypass the oil filter element. First is the 50 psid bypass valve built in to the oil filter mount. Second is an internal bypass valve inside the oil filter itself. Maybe if Wayne (amsoilman) reads this he can chime in with at what pressure drop across the oil filter element the internal bypass typically kicks in. Anyhow, during cold starts when the oil is thick, unfiltered oil from the pan will bypass the filter element and flow directly into the engine until the oil warms up a bit. Therefore it is wise to keep any foreign material out of the engine oil. So again the caution about the foil seal applies.



Since the engine lasts a good long time even with this normal small amount of "dirty" bypass during cold starts, I would not worry at all about pouring unfiltered clean oil directly into the filter. Just make sure you can account for the entire foil seal and pour from a new jug where you are only tipping the jug to the side, not upside down. That way in the rare event there is something at the bottom of the jug it will stay there. And, of course, watch the oil closely for anything abnormal as you’re pouring it in.





Here is a decent description of how the oil filter works: All About Oil Filters

I could be wrong, but I thought the second bypass was at the oil pump. At 75 psi a valve at the pump opens and dumps oil back to the pan to keep the cold psi down. But oil for the block is still filtered. I think the only time it bypasses the filter is the 50psid, which if you think about it is HUGE. With cold oil I never see above 80psi, even if its 70 at idle its only 75-77 at 2000, so that bypass is used every time the block is cold.

 

[brods]

The 75 psid "pressure regulator valve" at the pump limits max system pressure and routes the oil back to the pump suction. Makes sense because that will heat the oil quicker during cold starts. Since it doesn't directly effect dirty oil bypassing the oil filter I didn't mention it.

 

[AH64ID]

The 75 psid "pressure regulator valve" at the pump limits max system pressure and routes the oil back to the pump suction. Makes sense because that will heat the oil quicker during cold starts. Since it doesn't directly effect dirty oil bypassing the oil filter I didn't mention it.

Gotcha. . but thats not a psid is it? Its just 75psi.



And the oil takes until the coolant is above 180* before pressures look like warm pressures.

 

[brods]

Gotcha. . but thats not a psid is it? Its just 75psi.



And the oil takes until the coolant is above 180* before pressures look like warm pressures.

Lol, you got me since for all practical purposes the oil pressure acts against the valve's spring pressure only, so psi fine.

 

[JLovas]

excellent information on both sides... I've also been warned from older mechanics that dry intalled oil filters run a risk of having the paper element dislodged due to the oil pump trying to force oil from the "dirty" side to the "clean" side. If the paper element has oil on both sides of it, its less likely to imploid on itself. I guess I'll keep pre-filling, but cleanliness is very important.



On the other hand, on modern farm equipment, spin on fuel filter must be put on dry, and then use a hand plunger or primer to bleed the air out and to ensure the injection pump only sees filtered fuel. Obviously fuel injection pumps have much tighter tolerences than engine components.

 

[brods]

Cummins replied on the pre-filling question

Jim, we recommned to fill the filter with clean lubricating oil before

installation. It is true that if the foil from the container was poured

into the oil filter, it could plug up the piston cooling nozzles. Must be

certain that the foil is completely removed from the container.

Please note the correction to my earlier post about the oil filter having an internal bypass. That was incorrect for the oil filters on our trucks... at least with Fleetguards anyway. Sorry for the confusion.



I am also waiting on replies from a few oil companies on what micron size they filter their new oil down to and if they've ever had plastic from the containers contaminate the oil. I'll post that info when it comes in.

 

[Grizzly]

Thank you Harvey for this great and informative thread.



Thank you brods for your vast knowledge and contribution to this thread.



george

 

[AABEN]

I would thank that a man would not let the FOIL fall in to the jug of oil even if he did I would think he would not let it get in to his eng. Now if I took it to town to have it changed that might happen.

 

[brods]

After looking into this some more, I will continue to pre-fill the oil filter by pouring it right down the center. The oil will come from a new, full jug that has sat for at least a week. If the foil seal does not come off cleanly and all of it cannot be accounted for, a different jug will be used to fill the filter. After filling the filter, the jug will be shook up to stir any settled additives back into the oil before being poured into the engine.







How I’ve come to this point is by talking with some of the big oil mfgs, searching the web and recommendations from Cummins and the factory service manual to pre-fill. While the oil companies were less than enthusiastic in giving specific information, somewhat understandable in today’s lawsuit happy environment, they did give some useful information when pushed. The bottom line is they said it is ok pour the oil in the clean side of the filter, that it will not cause engine damage. They said that plastic from the bottle contaminating the oil is very unlikely. They also indicated that some of the oils additives will settle out over time, hence the need to shake the bottle before pouring it in the crankcase.



Of course one has to be wary of information where the sources have an incentive not to disclose all the facts, so the search for information continued. This is where BITOG forum comes in. There are several threads about pre-filling the filter on the site. The best is one of the older threads where a Stinky Peterson says this:

Back to prefilling filters - luckily it doesn’t take very much oil to fill a filter, but still there is a risk. Many people don’t realize that the oil is filtered by moving from the outside of the paper to the center. Yet the center is where the oil gets put so it gets a free ride right to the engine. As I mentioned before you can minimize the contamination risk by letting the new oil settle and then don’t up end the bottle when you fill the element. To the best of my knowledge any particle big enough to cause problem will settle out if set undisturbed for a day or two. If you can fill the outside of the filter then the oil will get filtered so there shouldn't’t be a problem.

I bolded what is the important part imo. Whether you stock up on oil when its on sale or if you buy it before each change, it should be no problem to let the jugs sit for several days before using it to fill the filter.



This is not meant to change anybody’s mind on the practice. Just throwing it out there.



YMMV

 

[Batphreak]

Just changed my oil this weekend, and had to re-re-open this old topic. I bought my normal 3 gallons of Rotella 10W-40. Because of this thread I had mydelf all ready to make sure all that little foil seal was not before pouring oil into my new oil filter. I popped and cap on the first bottle of Rotella, and Surprise, no foil seal! It appears Shell at least has gone away from the silly foil seal and just a foam lloking seal built into the cap to seal the jug. So, I guess that still leaves the little plastic pieces to worry about.

 

[msgoodwench]

Actually this has been an issue for many years. Most peeps have just been lucky, or blamed the engine failure on age, loose nut behind the wheel, etc. :-laf Seeing some of the stuff that clogs up the pick up filter on the oil pump can leave you in awe as to how the motor ever ran at all.



There are some funnels that have strainers built into them, but they are difficult to find. The paint strainer idea does work very well, as does using a pair of old pantyhose, stockings or knee-hi stockings. Just be sure to use 2 as a loose fitting double strainer stretched across the top of the funnel, since the material used for stockings is rather thin and tears easily.



A little side note for you avid winter hunters:

If you don't have thermal undies with "wicking" material, or it's not yet cold enough for them, get a pair of women's tights. Yes, they do come in "super size" for large people. They're like a super thick pair of hose that'll keep ya warm and cozy and no one will know the difference ... .

The tights also work really good for putting on wetsuit for diving or cleaning your grungy pool (don't laugh, they work really well and you wash the gunk right off). Anyone that has ever worn one knows that putting on a wetsuit is like trying to put on a second skin! :-laf

 

[AMink]

A little side note for you avid winter hunters:
If you don't have thermal undies with "wicking" material, or it's not yet cold enough for them, get a pair of women's tights. Yes, they do come in "super size" for large people. They're like a super thick pair of hose that'll keep ya warm and cozy and no one will know the difference ... .
The tights also work really good for putting on wetsuit for diving or cleaning your grungy pool (don't laugh, they work really well and you wash the gunk right off). Anyone that has ever worn one knows that putting on a wetsuit is like trying to put on a second skin! :-laf

Off topic, but it reminds me of skiing in Pennsylvania as a kid. A lot of the guys would use tights because we couldn't afford any of the "good" thermals. Worked well. Ah, memories!

 

[CharlesHoward]

Hmm... Neither the Haynes Repair Manual 'Engine Oil and Filter Change' (page 1-16) or the humorous "How to change the Oil in your Turbo Diesel Truck" TECHNICAL TOPIC from TDR 57 written by Andy Coyle mention pre-filling the filter. One step I added to these procedures is to bring a step stool to more easily reach the Oil Filler cap when the truck is on the lift I use... I will add cautiously pre-filling to these instructions I use for my once/year oil changes.