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YOUR RESEARCHRevisited: Prefill oil filter
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Some are the type that CANNOT be pre-filled ( for those who think that not pre-filling is so so bad..)
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Yep, Porsche , me , Jake ,Charles , all recommend not to "pre-fill" the oil filter on a new or rebuilt engine where there is no oil in any of the oil galleys, the oil cooler, the oil pump, the heads, lifter cradle ect..it is all just a bunch of air pockets.....
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I know about Yaz's motor and yeah, that whole situation confounds me, especially because I pre-filled every change.
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Now when that happens the car, the engine starts with no oil, because the oil pump has to fill the filter, then the oil circulates to the moving parts of the engine and that can add years of damage in just a single start.
There are probably also builds out there that did not experience bearing failure while pre-filling the filter, but that likely introduces additional variables (assembly lube vs grease, were the crank carrier and main bearings left untouched, use of oil priming tank, etc.).
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The theory is the air between the sump and the changed/pre-filled new filter and the air after the new filled filter can cause lack of flow for an extended time, moreso than an empty filter as all that air on both sides of filled filter is compressible.
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The theory is the air between the sump and the changed/pre-filled new filter and the air after the new filled filter can cause lack of flow for an extended time, moreso than an empty filter as all that air on both sides of filled filter is compressible.
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Fill " the oil filter
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Yep, Porsche , me , Jake ,Charles , all recommend not to "pre-fill" the oil filter on a new or rebuilt engine where there is no oil in any of the oil galleys, the oil cooler, the oil pump, the heads, lifter cradle ect..it is all just a bunch of air pockets.....
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Now when that happens the car, the engine starts with no oil, because the oil pump has to fill the filter, then the oil circulates to the moving parts of the engine and that can add years of damage in just a single start.
There are probably also builds out there that did not experience bearing failure while pre-filling the filter, but that likely introduces additional variables (assembly lube vs grease, were the crank carrier and main bearings left untouched, use of oil priming tank, etc.).
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Brad, maybe you could do an experiment and log the time it takes to build oil pressure after an oil change with both a pre filled filter and non pre filled and see what it says.
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The theory is the air between the sump and the changed/pre-filled new filter and the air after the new filled filter can cause lack of flow for an extended time, moreso than an empty filter as all that air on both sides of filled filter is compressible.
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The theory is the air between the sump and the changed/pre-filled new filter and the air after the new filled filter can cause lack of flow for an extended time, moreso than an empty filter as all that air on both sides of filled filter is compressible.
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The theory is the air between the sump and the changed/pre-filled new filter and the air after the new filled filter can cause lack of flow for an extended time, moreso than an empty filter as all that air on both sides of filled filter is compressible.
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I believe Jake and Charles recommend not prefilling, which I have never done. Lake claims in his Porsche engine there was no bearing material after prefilled and that previous changes without prefill there was. Starts talking about this at 6:30.
You Tube
Bullshlt... The filter is full every time you start the car. The oil is perfectly clean out of the bottle. Certainly cleaner than it is at 5k miles. I don't have to watch a video to know that what I have been doing for 25 years and hundreds of oil changes (pre-filling the filter) is the right way. Not going to waste my time on this pointless question. Why am I wasting my time even answering?
I have pre filled my filters on every oil change it was possible to do so since I was a kid. The M96 when the spin on adapter went on, the dry sump system in the car now, all the families various DD's... all of them.
Brad, maybe you could do an experiment and log the time it takes to build oil pressure after an oil change with both a pre filled filter and non pre filled and see what it says.
There is a drainback valve built into good filters precisely so you DON'T have an empty filter when you start the car each time.
"And here is the big thing. Most filters these days have check valves in them, and the primary one is an anti-drain back valve. That anti-drain back valve prevents the oil from being syphoned out of the filter when the engine is shut off. Now when that happens the car, the engine starts with no oil, because the oil pump has to fill the filter, then the oil circulates to the moving parts of the engine and that can add years of damage in just a single start.
"
Quote from this article:
https://motorweek.org/goss_garage/oi...%20shut%20off.
My point is that experts here have said not to prefill. And why so hostile?
https://rennlist.com/forums/996-foru...l#post19009509
Originally Posted by KentBigDog
@Charles Navarro
Why do you recommend not prefilling the oil filter with the spin-on? I've always filled my oil filters to reduce the amount of time the motor is without oil pumping through the engine.
We have seen several instances where the oil system ends up with an air lock and the engine won't have any oil pressure. Jake recommend against pre-filling any oil filter.
There are plenty of engines with filters that go on upside down or sideways that cannot physically be pre-filled, so installing a dry filter on your engine won't cause any issues.
Discussed here last weekend:
https://rennlist.com/forums/996-foru...l#post19093002
Oil is the cleanest it will ever be out of the bottle, I have no idea what Lake is referring to when he says some people think it's dirty.
I think you're overconfident in your response. There are many engines that it is not possible to pre-fill the oil filter because it's mounted horizontally or inverted. Try pre-filling a Mezger and let me know how it turns out for you.........
Something to note: A cold start on an M96 engine has a DME timer that decides what RPM target should be hit immediately after starting the engine. The longer your car sits, the higher the RPM target. On my �99, if it sit for over a week, I can easily hit 2,000-2,500 RPM. I remember reading somewhere, but cannot find it, this has to do with the oil pump design. The oil pump design is such that it can have trouble priming or pumping unless its internals are moving fast enough. Maybe it�s because the pump sits higher above the oil level, or maybe there�s another reason.
This is one reason why some also don�t recommending pulling the fuse that operate spark, and turning the engine over for many seconds to prime the engine with oil after major service work or a rebuild: the starter cannot turnover the engine fast enough to prime the system. Only a big spike in RPMs can do this.
So what is often good advice in general, and I think pre-filling is good advice generally, it may not be suitable in every case.
Yep, Porsche , me , Jake ,Charles , all recommend not to "pre-fill" the oil filter on a new or rebuilt engine where there is no oil in any of the oil galleys, the oil cooler, the oil pump, the heads, lifter cradle ect..it is all just a bunch of air pockets..... This is the most important scenario where having a slight " liquid block" in the middle of the system can delay pressure /flow build-up......The best procedure is to start the engine then shut it down 2-3 times, then leave it running..
Or if you want to do it the sure fire best way, then put the required oil in a pressurized container and pump it into the oil system at 100 psi.....( stock cartridge filter,,not one with a drain-back check valve)
Sure the other scenarios pre-filling the oil filter can be slightly more beneficial then not pre-filling, but you will find no such recommendation in the Porsche service manual.....And as people are creatures of habit who always want to do it one way or the other at all times....
Although the Mezger is a dry sump engine, it does have a sump, with a drain plug, that holds some oil. Some folks will pour 1/2 a quart of oil into the sump before installing the new filter. So, in a way, that's pre-filling the system to cut down on the semi-dry running time.
I think there is something funny going on iwit this argument for or against the prefill. The dirty oil claim is nonsense, It is fresh oil.
Here is the setup: I change the oil and filter in my car every 1,000 miles. (gives me something to do, can't hurt and is super easy). My car goes into professional storage this time of year and I only had a couple hundred miles since the last change so I just changed the oil and did not change the filter, which would be like pre-filling it, wouldn't it? Car ran fine. Have LN spin-on and use the larger NAPA Gold 1258.
When you remove the filter you remove the oil past the filter. So you still have oil between between the filter and the top of the engine that will start lubrication immediately.
Edit: Tom said it better below.
You say you changed the oil, and said you did not change the filter. So if you didn't REMOVE the filter, no, not same thing. Removing the filter allows the oil passages above the filter to drain back into your drain pan under the removed filter. The theory is the air between the sump and the changed/pre-filled new filter and the air after the new filled filter can cause lack of flow for an extended time, moreso than an empty filter as all that air on both sides of filled filter is compressible.
Unless someone can show hard data that sufficient oil pressure is reached with an empty filter before a full filter, and that test is collaborated by a second person... I say it is pretentious smoke blowing.
So I challenge anyone to show hard data.
Should be easy. Real time pressure monitoring at the same time as an RPM graph. Time in 100ths of a second until oil pressure reaches say 30psi will definitively answer the question.
(if your argument is based on not filtering the fresh oil, then filling the outer holes and allowing the filter to gravity filter solves that problem)
Unless you are willing to do, or have done this test; how is what you say anything more than an opinion?
In the middle of an oil change, I left the car on the lift a few days ago and will be back to fill it next weekend. Thought to myself, I should lookup the reason for the non-filling recommended of the oil filter. So glad someone else started an oil filter thread.
I hope nobody bites on this challenge. Even if a data point of one proves something one way or the other, that�s still not scientific. We may end up with a Galton Board problem.
Let�s spend time elsewhere.
Trust the true experts, four of which were already named. Or don�t trust them. Either way, it probably won�t affect 95% of the people.
Is Lake Speed not one of the experts in this area? I started this thread based on his assertion to prefill goes against what I have been doing and is recommended by Jake. His reasoning is based on analyzing the oil that has been changed both ways.
Really was trying to get a consensus. I know that's difficult with this group.
Your point is well taken. Lake has re-branded himself as the Oil Geek recently and is now providing more generalist kind of information rather than Porsche-centric information it would seem. He offers good information especially about tribology but to be a constructive critic his video could be more thorough in addressing some of the things we have discussed and recognizing there could be some caveats especially among his Porsche owning viewers which there are many. I would consider Jake, Charles, Porschetech, etc more experts than Lake on the M9x by far. Those guys mentioned have a lot more "hours" on this engine and have made mistakes that they learned from. Like most things in life, experience trumps all.......
Jake also says to crank the engine and immediately shut it off when it catches, over and over, until you see the oil pressure gauge move. Then start the engine and let it run.
Jake vs. Lake -- has a kind of a ring to it.
C'mon man, you're smarter than that.
He would be, except his advice runs counter to what Jake says, so he's disqualified by many. This, despite the fact the his conclusion seems to come from analyzing comparative data he collected.
I know about Yaz's motor and yeah, that whole situation confounds me, especially because I pre-filled every change. Maybe there is a distinction between a run of the mill change (like what I was doing) and what is best for initial start up of a fresh engine.
What I do know is, you have good tools to make an educated decision yourself, that being the case, what I don't understand is - why would you give a **** about what the people here say to do.
Did you watch the video at the time stamp I provided? He is talking about his boxster engine.
It does sound like the first two times after rebuild he did not prefill.
So, you would prefer that any of the people you mention perform an oil analysis on your M96, because they are the experts ?
The point of the video was that through analysis of oil samples an unfavorable data point was found and through a change in the oil change process, it was corrected.
What difference does it make what the motor was ?
Why did Lake change the oil at 138 miles after the first start on a rebuilt engine?
Why was there less material in the oil on the second change?
lol
I�ll stick with NOT prefilling the filter as recommended by the people with the most experience working on the M96 engine.
And it has nothing to do with idiocracy of the oil being �dirty�.
I like Lake, and I'm sure he knows more about oil and oil formulation than I do, but I would like to ask him some questions about what he posted...Like he mentions the fresh new oil had 52ppm of particles in the oil that were larger then 14 microns,, yet none of that showed on the wear metals or dirt ( silicone) maybe it is included in the additives as big clumps of additives, but then why did it have 331ppm of particles after it was in the motor ( without starting) and still didn't show on the lab report as a wear metal or dirt ( silicone), so what is it.... unobtainium ?
I'd like to ask him some more questions also but I think I already know what his answer will be, and I think he enjoys making videos too much..but with a new engine it is not unusual to have break-in metals in the first couple of oil changes, then have none, that is pretty typical...
Here is a bunch of UOA's see if you can tell which ones were pre-filled vs not pre-filled ? Some are the type that CANNOT be pre-filled ( for those who think that not pre-filling is so so bad..)
see if you can tell which were pre-filled vs which were not pre-filled
Ok as a hint, the 997.2 cannot be pre-filled
Because not all motors are the same. Making blanket statements should give you pause... anyway, let's not be petty shall we?
It seems you don't understand Jake's point since you are going back to an unfavorable oil analysis. The video is nonsense.
I'm not really following you. Did I make the blanket statement or was it in the video ? My point was if the guy who made a living analyzing oil and making suggestions to paying customers on how to enhance the longevity of their engines through changes in oil type, routine etc... says... I didn't like what I saw in this analysis so I made a change to the system and the measurement of that change showed an improvement - many people here have been trusting this guys analysis for years, so why is it now nonsense ? Is all the other advice he gave through his oil analysis nonsense as well ? I don't see how that benefits him, or his reputation to post nonsense.
As to why the specific engine doesn't matter. The data doesn't know what type of engine is producing it, the data, testing, results are what they are.
As far as Jakes point, yeah... I don't know what you're getting at there.
I'm not saying do one thing or do another thing... I know what I did and it seemed to work OK for me. Seems as though others do it different, and it seems to work OK for them. I just find it interesting that people are so quick to say the guy who everyone looked at for answers on oil now doesn't know what he's talking about or infer he's doing it for the views.
It would not have mattered if Lake had pre-filled on his brand new engine. You can "prime" and engine to completely get ALL the air out of the oiling system before starting and you will still get break-in wear metals .That is the reason to change oil after 50 miles then 500 miles on new rebuilt engines....no matter what you do...new parts have to wear-in...
Something about oil that brings the best and worst out of us.
It's impossible to prefill my GT3 engine's oil filter. I've changed my oil every 5 to 6K miles without pouring new oil anywhere but the oil fill tube. My engine has more than 152K miles on it with no issues. I always spend my time driving, not fretting.
Additionally, even if the M96 engine is different, most oil changes take place shortly after the engine was run, so there is still lubricant coating the critical parts anyway. But do what makes you happy.
Not looking to bicker here -- it was Lake's video making the blanket statement or at least not being clear that there could be caveats IMHO.
Again I don't want to bicker but your statements indicate that you don't at least understand Jake's points -- be them right or wrong. His point is that what is unique about the M96 is where the pump is placed in regard to the oil level in the engine. It is a miscalculation to think that all engines are the same when in fact it is an extremely important variable for several reasons.
Lake is excellent and I like him a lot, he knows tribology very well. But I had a well documented issue with his data years ago that I was correct about and they made a mistake........ and we don't have to get into that again.
I think the more important thing than pre filling or not is to doing 2-3 quick turn overs of the engine to build pressure. I believe this is more important on the larger spin filters also... It takes a lot less time for pressure to build and the light sometimes never comes on if this is done right. Just my opinion..
I (finally) just finished watching the video. I like Lake too, but that voice... let's just say I prefer to take him in small doses. Anyway. That's not the point of my post. My point ties in with what you say above.
tldr; Lake's Boxster testing was incomplete and therefore inconclusive.
He hypothesized that not prefilling caused bearing material to appear in the oil samples. A fair hypothesis given the evidence at hand. So he prefilled, tested again, and presto, no bearing material. He then concluded that prefilling prevented bearing material from being present. However, as you mention above it was a new motor and a few bits of bearing aren't unexpected; in other words, there is at least one other plausible explanation for the result than the one in Lake's conclusion. To support his conclusion he would need to do another series where the filter is not prefilled.
My view is that it doesn't matter whether you pre-fill or not for routine oil changes. In some engines you may get to higher oil pressure faster (some slower). Way too many design differences/variables to generate a blanket statement. The critical scenario is initial start-up on a new M96 engine build where the oil supply channels from the oil cooler to the main bearings are dry. Jake has tested this specific scenario and determined it takes 3-4x longer for oil to reach the bearings with a pre-filled filter. This can result in damage to the #7 main, which leads to starvation of the #6 rod bearing and a subsequent spun rod bearing within 40-100 miles. There are probably also builds out there that did not experience bearing failure while pre-filling the filter, but that likely introduces additional variables (assembly lube vs grease, were the crank carrier and main bearings left untouched, use of oil priming tank, etc.).
From my hands-on M96 engine building experience:
Pre-filled oil filter: spun rod bearing at 70 miles
Dry oil filter: 3000+ miles (and counting)
FWIW I do testing and data analysis of extremely complex and expensive systems for a living. My sample size of two is not statistically significant, but good luck finding someone willing to spend $20k+ per data point.
The video from Lake that I watched shows him testing time to achieve oil pressure in a non-M96 engine, and discussion of wear metals in back-to-back oil changes of his recently built M96. Let me know if there's a more relevant video that I missed. I don't recall him mentioning the state of the oil filter on initial start-up of that engine, but I find it hard to draw anything meaningful from that video.
From the prospective of an M96 specific business (engine building, parts supply, product development, etc), the recommendation to not pre-fill makes sense to me when you consider the following generalized possible results:
Option A: May provide benefit under general circumstances, but introduces risk of critical failure under very specific circumstances.
Option B: Eliminates risk of critical failure under very specific circumstances, but may not provide additional benefit under general circumstances.
Apologies, I saw the V8 in the video and missed the Boxster part at the beginning of the 6.5-min mark. Whoops. Now I see why this thread exists. Huge Fail on my part in not RTFM!!
Skimming this thread, is there a distinction if pre-filling or not pre-filling the oil filter applies to those doing a routine oil change vs first oil fill on a newly built engine? Seems like some folks are chiming in saying it's fine to do during a normal oil change while Yaz has had bad experience with it but on a freshly built motor that never had a drop of oil in it before. Or maybe it doesn't matter ....
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Yes, it matters greatly ....during routine maintenance it doesn't really matter because the oil pump gears are wet and a lot of oil still remains in the system..
But after a rebuild, there is no oil except where oil is put during assembly ( or assembly lube) and the oil pump gears are dry ( unless you intentionally lube them) so putting on a pre-filled oil filter can create a slight "trap" that a dry oil pump will have difficulty in pushing through..
Let me show a visual and get a little deeper into the physics..
The red X is a 1 inch channel from the oil pump inlet that goes back half way of the engine then down to the bottom of the Sump
The yellow x is a 1 inch channel that goes all the way to the rear of the engine then down to the oil filter
From the oil filter a 1 inch channel goes up to the top of the engine to the oil cooler before going back down to the main oil galley that feeds all the bearings and heads..
The green line represent the oil level when filled.
During routine oil changes all of this is wet and a lot of oil is still everywhere even though a lot of air does get in, the wet oil pump has no trouble pushing air though and atmospheric pressure pushes oil up to the oil pump gears and the system is "primed"...
But after an engine rebuild, all of this dry, the 1 inch channel to the bottom of the Sump ( red X) ..the oil pump and gears , the 1 inch channel (yellow X) all the way to the oil filter..all is dry....So IF you install a pre-filled oil filter it creates a bit of a "trap" ( like a "P trap" under the kitchen sink) and when you fill the Sump with oil, the oil will not even go up the pick-up tube to near the pump ( the green oil level line), the oil will not even go up to the oil fill line, it will be empty all the way to the bottom of the Sump ( unless you fill the Sump first, then install the pre-filled filter, but then the pump gears are still dry.)and the pump gears being "dry" will not push air through the wet oil filter media (unless it is turning at a high RPM or has been wetted or lubed or packed with a petroleum jelly.).so if you start an engine like this it will not build oil pressure untill it is too late..
So there is a lot of things going on and many ways to slightly help or hurt the situation..
Air can be pushed through a dry filter media easier then it can be pushed through a wet filter media...
AND if you just install the filter dry ( not pre-filled) and start the engine ( not just spin it with the starter because the starter RPM is not quite enough to push the air out) the pump will spin fast enough to push all the air out and prime the system.
There are many ways to skin a cat, and Technicians know many ways fix a car ( ie. easiest/ safest/best but more difficult/best but more risk if not done to the "t")
