As some of you know I am a recovering gasser (4 months gas sober)....I had the dealer fo the first oil change since I got like the first 10 free...However I cant wait on those dummy's to fit me in. So I am gonna just do my own this weekend. I know on these you are supposed to fill the new filter before putting it on. My question is why? I have done oil changes on tons of different vehicle including some diesel tractors and we never did this on any of them. At first I though maybe cause the filter is so large. But the filters on our tractors is larger than these...So I am just curious as to why you are supposed to fill the filter first...Is there some difference between diesel and gassers that make this necassary? (yes I did a search and found a 100 responses saying to do this but none that really explained why)

 

jimc11,
i always prefill every oil filter on every engine that i ever touch. i guess that i have just always considered it as one more step that i could take just to make sure i did my part to ensure longevity. as far as i always understood it, when you put a ''dry'' filter on the engine, once the engine starts- it has to soak the new oil into the filter media before it continues to circulate through the engine. that means that the engine is running without lubrication- more than at a normal startup (where i have read for years that most engine wear occurs). by prefilling or presoaking the inside of the new oil filter with new oil, its far less ''dry '' time without oil. i dont know - maybe the difference is only 1 second or so . but, with an engine that costs sooooo much , why take a chance?

 

The issue of problems with prefilling the oil filters arose after some engines were damage by foil occluding the piston lubrication nozzles after the filters were prefilled and foil from the oil bottle was accidentally dropped into the filter. The oil that is put into the filter enters the engine unfiltered, foil and all. I still prefill my filters but take extra care to insure that no foil accidentally goes into the filter.

 

cheap insurance for a little bit of time. i have always done the same as frank. every second that the engine is running and filling up the oil filter is a second that it isn't getting maximum oil flow. probably won't hurt anything if you didn't but i would rather be safe than sorry.


britt

 

I agree....I ALWAYS fill up the filter before I spin it on....as I understand it, the oil pump fills the filter FIRST, and then the oil goes from the filter to the main and rod bearings....

Maybe it does not matter, but I don't want my engine running dry for any length of time if I can help it...just my opinion

Besides, it only take a minute or two, unless you spill it all over the floor like I did last week...oops!!

 

My 03 is the fourth CTD I've owned ('91, 93, and '97). Either the oil filter was easy to access and the fuel filter was not or the fuel filter was easy while the oil was not. With my '03, the fuel is easy but the oil filter requires me on my back with the long reach to make it thread. I wish they would make one engine where both were easy to get at.

 

Hard to say...
I've always filled filters, even the itty bitty ones. This filter is large it also takes 3 or 4 top offs before it's really full. I don't feel like experimenting to see if the manual is just suggesting or really requiring. Then again, I let my turbo cool down too.

 

the most important reason to prefill the filter?turbo-bearings.there is a line that runs from the oil filter housing to the turbo that feeds the brgs.oil,if you dont fill the filter the brgs will be started dry for the few seconds that it takes the engine to fill the filter.just my .02 worth.
04.5 600 CTD 6sp 3500 SRW 4x4 LWB

 

The majority of wear to an engine is at start-up. Anyone familiar with large industrial equipment knows that there is a separate oil pressure feed that must be started before starting the equipment. Otherwise, bearings get wiped out. Even boaters with large diesel engines will sometimes add a separate pre-startup lube system to protect the engine. So, it makes sense to prefill any reservoirs (oil filter, lines, etc) so that the instant that the engine starts, the oil is not delayed in gettiing to the wear surfaces. Frankly, I'm surprised that there is not an after-market pre-start lube pump routinely offered. It matters little whether the engine is a gasser, diesel or a steam turbine, engines need oil the instant they turn over!

 

Actually, there is. Amsoil makes a "pre-oiler" that bolts onto their dual bypass filtration system (or separately, I think). I've been going back and forth deciding if I want to make the investment. It seems that most of guys on this site think that it probably isn't worth it. I'm not so sure ... then again ... I'm not convinced either way.

 

For those of you that prefill the filter, do you just pour the new oil in the big hole in the center of the filter or the little ones on the outside of the filter?

Just curious, because if pouring in the big hole the oil would not be filtered correct? Does this really matter?

Thanks

 

it doesn't matter... if you really start thinking about it, if you got 15w40 in the sump, and you are somewhere really cold, chances are on startup, your oil pressure can go past the oil filter bypass pressure, and that will dump unfiltered oil into your system... if you are pouring from a clean bottle, and there is no foil on the bottle, just fill down the center, or the outsides, or don't fill it at all... either way is ok...

 

OK tell me if I'm crazy but I think pre-filling the oil filter has a disadvantage and is a [B]bad idea[B].

Tell me if this makes sense or if I may be missing something.

If you pre-fill the filter, your oil pump has [B]two[B] issues to work against instead of one (if not pre-filled).

1. The oil pump is essentially dry after an oil change and has to create enough suction using compressible air to pull oil from the pan through the pickup tube into the pump housing. This is hard for the oil pump to do because the air in the "dry" pump is compressible, thus creating a [B]lag[B] in the overall time from "no oil in pump" to "oil in pump".

and at the same time...

2. If you pre-fill your oil filter, your oil pump must push the large volume of oil out of the filter into the galleries and bearings etc... while it's DRY and fighting to move the air in the pickup tube. not to mention to actually move the oil out of the oil filter it has to push on a section of compressible air between the pump and filter.

So... looking at the oiling system from the [B]pickup[B] to the [B]oil galleries[B] we have:
1. Oil in the pan
2. An air space between the oil level in the pan and the oil pump (makes it hard to pull oil up to the pump)
3. Another air space after the pump right before the oil filter
4. and then we have a pre-filled oil filter which has a lage quantity of oil which won't move so easily with compressible air pushing on it.

By the way, I believe that little oil can symbol painted on the oil filter (as part of the installation instructions) does not mean "pre-fill the filter with oil", it means "lubicate the o-ring gasket with some oil before installation".

Am I in left-field about this, I hope I explained it well enough.

Eric

 

Never prefill anything except a new motor on first startup and hadn't done a engine rebuld or replace in 2 decades.