Filling up new oil filter prior to installation

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Originally Posted By: Jim Allen
Here and there, you see a manufacturer council NOT to to prefill the filter, citing that you are essentially pouring "dirty" oil into the clean side of the filter. I don't go along with that and I prefill when possible. But is it vital? I don't think so. As has been said above, there isn't a rash of failures from not doing it and the vast majority of OCs are done without it.

There are a few specific engines that can really benefit from it because of the oil pump design and location. Rover V8s, and the Buick V8s their design was based upon, AMV V8s are just a couple of engines that will loose oil pump prime easily because of their front cover-mounted oil pumps that get very loose with age and can be difficult to prime. Prefilling helps in these cases. I spent many years working on Land Rovers and learned that when you OC them, you don't let them sit long periods with the oil drained and the filter off because the pump would lose prime and you could have trouble getting it to prime if you didn't prefill the filter (which was messy because the filter is nearly horizontal). I had the same experience with a couple of AMC V8s.


So what the council is saying is that oil poured directly from a sealed container is "dirty"? That is preposterous.
 
Originally Posted By: stchman
Originally Posted By: Jim Allen
Here and there, you see a manufacturer council NOT to to prefill the filter, citing that you are essentially pouring "dirty" oil into the clean side of the filter. I don't go along with that and I prefill when possible. But is it vital? I don't think so. As has been said above, there isn't a rash of failures from not doing it and the vast majority of OCs are done without it.

There are a few specific engines that can really benefit from it because of the oil pump design and location. Rover V8s, and the Buick V8s their design was based upon, AMV V8s are just a couple of engines that will loose oil pump prime easily because of their front cover-mounted oil pumps that get very loose with age and can be difficult to prime. Prefilling helps in these cases. I spent many years working on Land Rovers and learned that when you OC them, you don't let them sit long periods with the oil drained and the filter off because the pump would lose prime and you could have trouble getting it to prime if you didn't prefill the filter (which was messy because the filter is nearly horizontal). I had the same experience with a couple of AMC V8s.


So what the council is saying is that oil poured directly from a sealed container is "dirty"? That is preposterous.

"Dirty" might not be the right description. However, I suspect that unused motor oil has small amounts of stuff that's gelled or maybe clumps of additives that have come out of suspension. I doubt it's much of an issue. On many vehicles, you're dumping stuff straight into engine parts that are supposed to be lubricated with "clean" oil. Just one pass, most of it gets trapped by the filter, and perhaps some of this stuff goes back into suspension after enough time at operating temp. Just my speculation though.
 
When I worked at a quick lube the owner had said that GM on the late 80s and early 90s Cadillac 4.1 and 4.5L V8s used an external oil pump.

If the filter was put on empty, the oil pump could lose prime. To help alleviate this, we pre-filled the oil filter before installing.
 
A few years ago when i was doing marine diesel mechanics, my boss knew a few guys who would change the oil on K19 cummins (big marine engines, 25 gallon or more oil capacity) without prefilling the filters. they spun the main bearings on a few engines until they finally realized they needed to prefill them.
 
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there a million million car that install filter without fill it, its still fine on the road. But I alway fill it up a bit before install, made me feel better that way ^^
 
Originally Posted By: stchman


So what the council is saying is that oil poured directly from a sealed container is "dirty"? That is preposterous.


It's true. But you are overreacting. Is it so "dirty" that it's dangerous to put in the engine? With only a few exceptions, no. Is it as pure as the driven snow? Again, no. The contaminant levels vary a lot and I was shocked to see how dirty some oils actually are. "Dirty" might be too harsh a word but in truth, some fresh oil gets cleaner after it runs thru the engine oil filter a couple of times.. especially in the area of large particles. There is no standard for the contaminant levels of new oil, beyond what the lube manufacturers enact themselves. Most of is reasonably clean but even good companies can have occasional trouble with cleanliness and lesser companies... well.

I was given a long list of PC analysis of various oils and usually do a virgin PC on an oil I begin using. I have posted much of this info previously if you care to look. Again, of the oils I saw PCs on or tested myself, the oil wasn't dangerously dirty but not super clean. For me it was mostly a perceptual revelation. I had long "assumed" oil would be super clean. I was chagrined to learn it isn't.

Interestingly, of the bottled oils on the list I have, Chevron oils were the cleanest (it's by no means a complete list) and a Mopar 15W40 was the dirtiest. There were some PCs on bulk oil that were as dirty as some oils I have drained out of a crankcase after a normal OCI. There was an article on this in one of the trade magazines a few years back where the experts had some concerns on the storage and handling of bulk oils. I noticed not long ago that one of my local shops that uses bulk oil has a filtration system and that would ease my mind considerably. Think about it... from blender to retailer, that bulk oil might change tanks two or three times and you are relying on the transporter and the retailer to maintain some level of tank cleanliness.
 
Originally Posted By: Jim Allen
Originally Posted By: stchman


So what the council is saying is that oil poured directly from a sealed container is "dirty"? That is preposterous.


It's true. But you are overreacting. Is it so "dirty" that it's dangerous to put in the engine? With only a few exceptions, no. Is it as pure as the driven snow? Again, no. The contaminant levels vary a lot and I was shocked to see how dirty some oils actually are. "Dirty" might be too harsh a word but in truth, some fresh oil gets cleaner after it runs thru the engine oil filter a couple of times.. especially in the area of large particles. There is no standard for the contaminant levels of new oil, beyond what the lube manufacturers enact themselves. Most of is reasonably clean but even good companies can have occasional trouble with cleanliness and lesser companies... well.

I was given a long list of PC analysis of various oils and usually do a virgin PC on an oil I begin using. I have posted much of this info previously if you care to look. Again, of the oils I saw PCs on or tested myself, the oil wasn't dangerously dirty but not super clean. For me it was mostly a perceptual revelation. I had long "assumed" oil would be super clean. I was chagrined to learn it isn't.

Interestingly, of the bottled oils on the list I have, Chevron oils were the cleanest (it's by no means a complete list) and a Mopar 15W40 was the dirtiest. There were some PCs on bulk oil that were as dirty as some oils I have drained out of a crankcase after a normal OCI. There was an article on this in one of the trade magazines a few years back where the experts had some concerns on the storage and handling of bulk oils. I noticed not long ago that one of my local shops that uses bulk oil has a filtration system and that would ease my mind considerably. Think about it... from blender to retailer, that bulk oil might change tanks two or three times and you are relying on the transporter and the retailer to maintain some level of tank cleanliness.


So then by your experience pre-filling the filter is bad. All that contaminated new oil.
 
I didn't say that. Reread my first post in this thread. Prefilling the filter is something I do routinely.

I just pointed out that over the years, there have been a few engine manufacturers that mentioned specifically to NOT prefill the filter. Also, I was making a side point, since it segued into the topic, that new oil isn't necessarily super clean. None of the PC samples I have seen, other than two bulk oil tests, had oil dirty enough to be dangerous ... just a lot dirtier than most of us would think and, IMO, dirtier than it SHOULD be.
 
Bulk oil keeps being mentioned ... but I would assume that bottled oil might be "cleaner", or at least as "clean" as new oil gets.

As far as pouring new oil in the valve cover and getting some on the valve train ... I don't think that is going to hurt anything at all. That oil just washes over the valve train parts and probably doesn't really have a good chance to penetrate any critical areas that are already saturated with oil.

I think as long as you are careful pre-filling an oil filter from a new bottle of oil, and ensure nothing like a piece of foil, etc from the bottle drops into the filter, everything should be AOK.
 
Originally Posted By: stchman
When I worked at a quick lube the owner had said that GM on the late 80s and early 90s Cadillac 4.1 and 4.5L V8s used an external oil pump.

If the filter was put on empty, the oil pump could lose prime. To help alleviate this, we pre-filled the oil filter before installing.


I would take my car there
smile.gif
 
If the engine has a vertically mounted filter then there is no reason not to. Just that much less dry starting. Just fill it roughly 3/4 of the way so nothing spills out.
 
I don't understand all the talk about horizontal filters being problematic for pre-fill. I fill mine a few minutes before using them and 100% of the time they look empty before I put them on- the media absorbs practically all of the first fill. I also do a second fill amount based on the orientation of the filter.
 
I've never pre-filled a filter in 40 years. (except race cars) I've never heard a peep out of any engine with a supposed "dry start". Oil light always goes out with 2 seconds of starting. But if it makes you feel better, go for it.
 
I always do. I learned, at least for me. in the past, when i had a 85 isuzu i mark hatcbakc, mid 90's, and a 95 neon, 2000's, a few times only on both cars, in warm spring wearther, used fram orange cans of death, at the time. no more..oil pressure issues on startup with both different cars. never with anothe oil filter. oil light would come on with the ornage cans.
few times i never pre filled. added 5w30 dino oils. mobil. starting key after oil change, thier would be a few second hesitant start, and ide get this loudish metal skid sound form the engine. obviulsy a cam or something. sounds never happens when i pre fill the filters. so! Ive learned, too pre fill always. then spin it on..
 
I try to fill the oil filters also but i know that is a giant no no with both Gm and chrysler i head it many times in a number of seminars for engine rebuilders an techs.
 
We did it every time with Chev small blocks, thanks to them being base end up. Of course, that was never the case with my Town Car, LTD, F-150, Audi, or G, mostly because of filter orientation. It's not worth worrying over.
wink.gif
 
I don't see why so many people have a hard time accepting Jim Allen's info about fresh oil and particle counts... If he's got hard data, what's to dispute?

Also, for the pre fill or die crowd, try to pre fill a cartridge filter.
 
I don't doubt JA's information regarding 'some' bulk new oil cleanliness. That said, still haven't gotten an answer to the far greater amount of unfiltered new oil that is poured down the fill hole that will come in contact with multiple engine surfaces prior to being run through the oil filter. Why would the relatively small amount of new oil poured in a new filter be more significant than that in the engine?

And it should be noted that Jim said he prefills his filters. Clearly the goal of reducing dry start time must outweigh any new oil dirt fear. But as said, prefill or not makes no significant difference in engine longevity.

And while we're at proving information, I'd like to see authoritative citing saying GM and Chrysler specifically discourage oil filter prefill. Anecdotal hearsay posted here doesn't cut it for me.
 
Originally Posted By: sayjac
I don't doubt JA's information regarding 'some' bulk new oil cleanliness. That said, still haven't gotten an answer to the far greater amount of unfiltered new oil that is poured down the fill hole that will come in contact with multiple engine surfaces prior to being run through the oil filter. Why would the relatively small amount of new oil poured in a new filter be more significant than that in the engine?


Only thing I can come up with is that pre-filled filter oil goes directly into the tight clearance bearings (mains, rods, etc), whereas oil poured into the valve cover and washing over valve train components isn't really getting into tight clearance bearings.

Originally Posted By: sayjac
And while we're at proving information, I'd like to see authoritative citing saying GM and Chrysler specifically discourage oil filter prefill. Anecdotal hearsay posted here doesn't cut it for me.


I'd like to hear the official GM and Chrysler reason too.
 
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