[Bims328i]

Hey there my friends,

I've been wanting to start this thread for a while now and have had my own OPG leak likely since I picked up my E90 at 73k miles. Now at 98k.

I've had a scanner for it since purchase and was exploring it one day after taking the car home and noticed it didn't have many oil CBS resets with 73k miles. I think it was 4 or 5. Meaning they were waiting until the absolute latest time to do oil changes.

I know these synthetic oils claim guarantees for something like 10k miles but I don't care what oil it is. The oil in an engine is like its blood and all you have is your puny oil filter to clean it.

Over time your engine oil gets contaminated with all sorts of things. Carbon, fuel, ect.

In my opinion even a synthetic oil cannot handle 10k miles of contaminant absorption. Even so, if it could, you would be pushing that to its limits which can lead to those contaminants leeching into the various gaskets and seals all across your motor.

I say this because I've been needing to do my OPG for some time now but I also do oil changes at roughly 3k miles.

I have a OPG leak that has since slowed down which I can only attribute to frequent oil changes. I check it every day I drive it.

Clean oil is not going to damage any seals or gaskets. Overly contaminated oil will which is why it is super important to keep your oil clean on you BMW.

Thoughts?

[Welcome to NBA Jam]

Your leak didn't slow down, it became less noticeable because you're refilling the oil more often and keeping it topped up. It has nothing to do with how dirty the oil is. Modern synthetics can easily go 10k miles or more. My 142k 335i had yearly oil changes stretching 10-12k. The engine was perfect. The only leaks it had were the valve cover, oil filter housing, and oil pan gasket which will happen to every BMW regardless of oil drain interval.

The only thing that causes an oil pan gasket to leak are heat cycles plasticizing the rubber. That's it. There's no other magic to it.

[Bims328i]

But I'm filling it less often. I'm tracking it my guy.

[Welcome to NBA Jam]

Originally Posted by Bims328i

But I'm filling it less often. I'm tracking it my guy.

Post data.

[lowrydr310]

Originally Posted by Bims328i

In my opinion even a synthetic oil cannot handle 10k miles of contaminant absorption. Even so, if it could, you would be pushing that to its limits which can lead to those contaminants leeching into the various gaskets and seals all across your motor.

Oh Efthreeoh, you have been summoned.

[Bims328i]

Originally Posted by Welcome to NBA Jam

Post data.

Well I don't have raw data sir but I do have a record of MY oil changes.

I'm just saying in terms of contaminants present even at my 3k change intervals are noticeably worn and smell of engine internals.

I check the level every day after arriving to work and my top ups have now slowed down. That's all the evidence I do have. After removing the shield for another service prior I noticed the front of the pan is not leaking anymore, like it shifted now to the back which leaks imo because it has all those surface changes. Just means it is more susceptible to leaking.

In my opinion if you have a beamer it is really important to keep your oil fresh in order to keep your seals from failing prematurely.

In the case of a seal that has gone solid, you cannot save it by doing more frequent oil changes.

I've watched and replaced other seals like VCG and OFHG already and noted the condition of the seals.

That's why I wanted to know your thoughts on the matter.

[Bims328i]

I wouldn't say it will fix the leak like a new gasket will but like I said, I was filling it up frequently and checking it daily. Noticed it is staying full a lot longer than before but I would still say I need to change the gasket as the OFHG was pretty bad.

It's like the interaction between the oil suspending the contaminants across all the hard-to-access seals I am considering that could benefit from more frequent oil changes.

Even in the case of an oil than claims 10k miles you're still pushing 10k miles of unknown contaminants into that oil running the engine. The oil can only hold so many contaminants and at any time, what is in the oil will interact with the all the internal seals of your motor.

My thought is more frequent oil changes will prolong the life of internal seals but I know heat cycles ultimately play another role in this.

[mainbearing]

Regardless, that oil pan gasket IS the problem and will eventually need to be changed. I used Permatex Ultra Black RTV on both sides to act as the real seal.

And I used the forum DIY on that:
https://www.e90post.com/forums/showthread.php?t=1180020

A new pan gasket and oil level sensor gasket (Ajusa)


The real, proper seal is:

[Bims328i]

I need to do the pan gasket soon. Thanks for the tips there mainbearing, how are you guys tagging users like that if I may ask?

I wish we had a test for gaskets on a car that had something like 3k syn oil changes since factory. Adding fresh oil never hurt any seal. It's always contaminated oil along with inevitable heat cycles that damage the seal which is why I'm starting to suspect it is the lack of frequent oil changes that can attribute to premature gasket failure as heat cycles should play a secondary role. The primary factor of premature seal degradation in my opinion is oil that is saturated with internal engine contaminants.

[e91Owner]

Originally Posted by Bims328i

I need to do the pan gasket soon. Thanks for the tips there mainbearing, how are you guys tagging users like that if I may ask?

I wish we had a test for gaskets on a car that had something like 3k syn oil changes since factory. Adding fresh oil never hurt any seal. It's always contaminated oil along with inevitable heat cycles that damage the seal which is why I'm starting to suspect it is the lack of frequent oil changes that can attribute to premature gasket failure as heat cycles should play a secondary role. The primary factor of premature seal degradation in my opinion is oil that is saturated with internal engine contaminants.

Nothing but CBS here… on my e91 that generally means every 2 years. About once a year at 14-15k on my e60. I doubt you’d see any difference in terms of gasket wear by changing at lesser intervals. The primary oil contantiminants aren’t more corrosive to them any more than the oil itself.

[Bims328i]

Originally Posted by e91Owner

The primary oil contantiminants aren’t more corrosive to them any more than the oil itself.

You can't be serious... The contaminants from fuel and everything else that comes from running your engine. Only the pure oil is free of these contaminants that are introduced simply by driving your car.

[e91Owner]

Originally Posted by Bims328i

You can't be serious... The contaminants from fuel and everything else that comes from running your engine. Only the pure oil is free of these contaminants that are introduced simply by driving your car.

Yes, I’m serious. You can change it every other mile, if you’d like, though. It’s your money…. It just won’t increase the longevity of your gaskets appreciably.

[Bims328i]

That is preposterous to change that frequently of course lol. Don't be silly. I was referring to something like maybe 3k when you think you can do 10k. Like I said, it is the oils ability to suspend contaminants within the capacity of the oil your engine requires. Do whatever you want of course.

[Bims328i]

Hey there Efthreeoh! Thanks for the pro tips as always. To clairfy, I was doing those 3k intervals mainly to catch up on oil changes within the CBS system.

Shortly after I purchased the car in June of 20' I had some vanos codes. Was still learning about it and ended up picking up a genuine set of two. Next was water pump then valve cover gasket along with the oil filter housing gasket.

I have since replaced all of this but I can't agree with heat cycles being the only factor in seal degradation. Even at 3k intervals, my oil is considerably dirty. On a molecular level you cannot tell me fuel and other unknown engine contaminants will not interact with the gaskets and seals within the internals of your engine to compound the obvious affects of inevitable heat cycles.

My argument is you may think it is alright to do these 10k-12k mile intervals while your oil at that point must be nearing its breaking point in its ability to suspend the contaminants within the oil itself so at some point the oil will become overly saturated.

Oil for an internal combustion engine is many things, one of which in my opinion is a medium to suspend engine contaminants. All in all, do what you like. It's your money when you have to shell out big bucks for all these repairs because you thought it was ok to do a 10k mile oil change. Not you specifically, just saying. Self-service oil change is not that pricy. In my mind, good preventive maintenance. Thanks again for your insight!

[Keith325i]

When I bought my car, the original owner had stuck to the bmw recommended oil change interval of 18k miles, which is obviously way too long. There was a sludge problem as a result.

I was in the same thought process as you in that I planned to change the oil every 3k miles to keep the engine as healthy as possible considering the service history. I changed the oil when I got it at 57k miles, then again at 60k miles. To be honest, the oil was perfect at the second oil change.

I did a lot of reading on forums like bobistheoilguy and watching YouTube videos and it seems to me that a 7k mile oil change is the most efficient in terms of oil wear. So that is what I will stick to.

[StradaRedlands]

I do 10k oil changes with LL01, but R&R the filter at 5k. Blackstone says I can do longer intervals, but 10k is a nice round number to keep in my head! You can run 3k changes if you want (it won't hurt anything), but send the oil to Blackstone to see what they say. I'm 99.9% certain they'll say to extend the interval. Report back with your findings!

[E93Seattle (Racerbruce)]

as strada said, if you haven't already begin a relationship with https://www.blackstone-labs.com/ for science-based oil analysis.

my last car, a 2007 z4mr s54 engine had a propensity for connecting rod bearing issues (not all of them) and i made every effort to manage this by utilizing blackstone's lab reports which compared my s54's data with all other s54 engines in their database.

it's very inexpensive and provides a level of internal wear, etc that cannot be seen without this data.

[Bims328i]

Thanks for all the info! I am planning to get the oil analyzed soon actually. I have been doing short oil changes myself, but it was mainly due to fact I bought the car used. I have been trying to do these to clean the engine internals out over time.

As before I don't have any raw data other than my oil changes but I'm not putting oil in it as frequently. To the point where I'm thinking "when is it going to need a half a quart??".

Adding I inspected the lower shield and the pan when doing a recent service and the front of the pan is not leaking anymore while the back still is.

My suspicion is that someone went a bit too long on oil changes which if running near 10-12k you are pushing the oil to its limits, which could give way to possibly go over the interval if you're not paying attention or don't want to fork over money to have it done.

So, the engine might have been subjected to a time where the oil needed to be change but wasn't. Heat cycles do play a primary role in the degradation of seals, but I cannot simply omit the fact various contaminants and their saturation that is found in overused oil will in fact play a secondary role in seal degradation.

To say otherwise is like saying the oil doesn't interact with every seal it makes contact with, in your engine.

Will all do respect Eftreeoh, your record looks like it is from someone who owned the car since new and actually knew what they are doing while taking care of their car. That might make your service record look very clean and a bit skewed in comparison to how most people treat their cars.

10k miles still seems like a lot of miles for ONE oil change but I hear you. In my specific case, I decided to do some short oil changes to try and clean the motor out over time.

I've done the valve cover gasket, oil filter housing gasket, both vanos at 76k miles (note I purchased at 73k miles) and a ton of other stuff while same here, no sludge but I examined my OFHG and you could smell it reeked of engine internals.

Years ago I used to vape, since quit. I literally watched a white silicone O-ring slowly turn yellow due to all the juice it came in contact with over time.

The same thing is occurring with your gaskets all across your engine. Of course, oil will have some effect on these seals but compounding all the contaminants that build up in your engine over the course of just a thousand miles is pretty considerable. Anything that is in that oil has the chance to then interact with all these seals.

You guys still haven't told me how you tag people in this forum like you do.
I am glad you have been able to go such a long time with such success and I hope she continues to provide you with many future miles.

[AlpineBoost]

Bims328i To tag someone type @ followed by their username.

[Hoody007]

My experience with NA BMWs is very similar to Efthreeoh - had a few 330Cis before my 335i and used the BMW CBS system. No issues with sludge. But in both cases the cars were well maintained from new.

For an N54/N55 (especially an N55 with rod bearing issues) that’s a different story - I’d do changes every 7500/10000 miles. But for an N52, provided you’re using proper BMW oil and filters, I’d go with the CBS. But this is on a well maintained car. As with any used example, it’s good practice to baseline all fluids upon purchase.

That being said I do find it interesting that the 2011+ models switched to a shorter interval-wonder if that’s to maintain parity with all of the other turbo motors used in the lineup that year.

[Welcome to NBA Jam]

Originally Posted by Keith325i

When I bought my car, the original owner had stuck to the bmw recommended oil change interval of 18k miles, which is obviously way too long. There was a sludge problem as a result.

I was in the same thought process as you in that I planned to change the oil every 3k miles to keep the engine as healthy as possible considering the service history. I changed the oil when I got it at 57k miles, then again at 60k miles. To be honest, the oil was perfect at the second oil change.

I did a lot of reading on forums like bobistheoilguy and watching YouTube videos and it seems to me that a 7k mile oil change is the most efficient in terms of oil wear. So that is what I will stick to.

Most Asian manufacturers spec a 6k-10k oil change interval or every 6 months. BMW, Mercedes, VW, and Porsche currently say 10k or 1 year. At one point in time Porsche spec'd 20k or 2 years which is the longest interval I've heard of, and even I'm a bit skeptical of that length. It's like they spec'd it for someone who drives a ton of doesn't drive at all.

Ultimately the interval decided by the manufacturer is based on the design of the engine, oil used, and a lot of testing. I've always stuck with what the manufacturer spec'd or when my car tells me.

[jsunma]

Originally Posted by e91Owner

Yes, I’m serious. You can change it every other mile, if you’d like, though. It’s your money…. It just won’t increase the longevity of your gaskets appreciably.

It's both an issue of money (which maybe the OP isn't concerned with...but if that were the case, then why not just never change the oil and get a new car when the engine seizes? There are plenty of people who do that. ;-) ) and also the environment. Changing the oil 3 to 4 times more often than necessary is contributing to overuse of a resource...and perhaps (if he's not recycling the oil properly, and even so...) contributing more to the waste stream that is necessary.

At any rate, changing the oil in order to preserve gaskets is a new one to me...and strikes me as pretty much nonsense. As others have said, if one is so very concerned with contaminants in the oil, then use a service like Blackstone. Otherwise, do what other people do...change the oil when the CBS says so or if you're more paranoid than that (or if you're over 230K like me on an engine that is running perfectly and the CBS system for oil has ended because that's how BMW programmed it), change it every 10K to 15K and get on with life. As it's said, it's a car...not a spacecraft.

(although I'll guess that even NASA isn't worried about excessive oil contaminants destroying gaskets...because that's just kinda nuts)