Oil pan leaking, heavily, at 20k miles. Anyone else?

[Cruiser124]

[QUOTE=M4drift;21312339][QUOTE=TurboM;21296742]When you say "we tore all of the subframe components off for nothing", are you saying they dropped the motor? If so, that sucks for a new car to have the motor pulled for such a silly issue.

The dealers should be able to figure this out pretty easily at this point with the detection tools they have given they know it's not just a simple oil pan leak. Venting on a forum is good for exactly that, venting, but no one is going to know what the issues is. The dealer will figure that out. Good luck



Actually there is a lot of great information and knowledge on the forums, and some very savy techs/tuners, for example Carythelabelguy, and many others. I'm also a tech/tuner and a mechanical engineer with an emphasis on automotive, so there's that too. So someone here could in fact know what the issue is, especially if they have experienced or seen it before, hence my posting about it. Normally I would tear this thing apart myself, find the issue, and fix it, and report to others on what I found in an attempt to help save someone time. I wish it was a simple oil pan leak, it's quite a bit more. This isn't exactly a venting post, this is an an attempt at an informative "if this happens to you, here's what to expect and try to avoid" thread. It was never the oil pan gasket, so if anyone sees that and thinks it is don't replace it until you keep hunting and most likely pull the trans. Due to the design of the motor and the slight crack at the corner of the oil pan and bell housing a leaking rear main looks like it's an oil pan gasket at the rear corner. There are also two oil passages on the back of the motor that have press fit inserts that can potentially leak as well inside the bell housing also looking like an oil pan gasket leak. Yes we dropped the subframe because you can't pull the oil pan off without doing so. No it wasn't the problem and was a giant waste of time. "Figure it out pretty easily"..... gonna go with no unfortunately. This has been ongoing for four weeks as parts aren't readily available for our cars and generally have to come from over seas. We replaced the oil pan gasket, week +, then pulled trans to find that rear main was leaking, ordered parts replaced rear main, then tested PCV pressure per BMW's tech department, not in spec, ordered new valve cover since it's integrated into the valve cover, has to come from Germany, that's another week from now. Just going through the motions replacing one thing after another for weeks upon weeks and still don't truly know what caused the issue. Rear mains on low mileage cars don't often just randomly fail. When I say that I mean it didn't just develop a slight leak or weep, it failed and oil was coming out steadily. The rear main was still completely seated and didn't push out at all btw and looked perfect.

If someone else had gone through this I sure as hell wish they had posted up about it so we could have avoided dropping the pan unnecessarily and so forth and gone straight for the rear main, but first tested crank case pressure before tearing down, etc. to eliminate a bunch of what if's and weeks of time.

My local BMW dealer has been great about helping to sort things out and resolve the issue. It's been a pain in the ass to track down the culprit and it's still an on going process. They have been accommodating, professional, courteous, and forth coming every step of the way, and have done their best to accelerate the process within the realm of what info they have to work with from BMW and the availability of parts.

For now it just is what it is but once it's finally resolved I'll keep y'all in the loop, unless I'm asked to sign a non-disclosure agreement, in which case this thread will disappear into obscurity lol.[/QUOTE


Did you ever resolve this issue? I recently purchased an e90 335 xi as a project car, knowing it had an oil leak. After inspecting the underside the leak appeared just as yours. At the back of the oil pan. Knowing it could be rear main seal or oil pan gasket I opted to start with the oil pan (easier to drop the subframe vs transmission when working on jackstand).

I now have the oil pan removed and can clearly see oil above the pan sealing surface... so I guess this means rear main seal?

A major concern I have, as you pointed out is the pcv system. With the oil pan removed the rear main seal seems to be protruding outwards past the engine block. This makes me think there is excess crank pressure. I have the mechanical ability to remove the transmission and replace the seal, but my fear is there may be an underlying issue and I certainly don't want to do the job twice.

Previous owner stated that after approximately 50 miles of having the valve cover gasket replaced the leak developed. To me this seems to coincidental. So.. could something have gone wrong when the valve cover gasket was replaced to cause excess crank pressure to push out the rear main??

Prior to this I'm told the car had no oil consumption issues, and it still drives very nicely. Just loses a quart of oil in 50 miles or so.

Any input you have is greatly appreciated!

[pbar]

I have a feeling I am about to go through this nightmare myself.
A couple of days ago I noticed a small puddle of oil on my garage floor.

Took it into the dealership and they are telling me that the oil pan is leaking "due to impact damage", needs replacing and it will cost $4000 parts&labor. Since the leak is supposedly due to impact, they will not cover it under warranty!

Below is photo the dealer sent me of the damage. From what I can see something has hit the structural reinforcement plate under the car: https://www.ecstuning.com/b-genuine-...l/31102284631/ (though neither I nor my wife even noticed an impact)

This is a structural member and bolts to the front axle crossmember: http://www.realoem.com/bmw/enUS/show...diagId=31_1123 - and even includes the front center jack point. Yet somehow the oil pan is allegedly damaged? All I can see here is leaking oil dripping from the obvious access hole, and some minor ding from road debris.

Repairing the oil pan hilariously involves 'Remove Front Axle', 'Remove engine support arm with engine mount.' ... well at least they don't need to disconnect the transmission too ;-) https://www.newtis.info/tisv2/a/en/f...ump/1VnXP2s4RH

I am hesitant to just 'suck this up' ... any suggestions about what I can do here?

EDIT: Updated information

I got the dealership to remove the skid pan and work out where the oil was actually coming from. It turned out that immediately above the impact area is an oil sensor mounted directly to the underside of the oil pan, and this is where the oil was leaking... no sign of any oil from further up around the seals.


We hoped it was just a cracked sensor (a bargain at $450), but sadly it looks like the impact occurred exactly on the end of one of the mounting studs, and this was enough to crack the casting of the oil pan itself (an $850 part).

Just why some engineer decided to put downward facing studs on the bottom of the lowest part of the engine I cannot imagine. (the sensor is actually a stalk that goes up several inches into the oil sump - surely it could have mounted to the side?)


So... not at all related to the OP's problem with oil seals, but perhaps a cautionary tale for those with aggressively lowered cars and not enough respect for the speed bumps.

[HPIA4v2]

Damn, BMW has not fixed this issue since N52, N54, N55 engines; all has oil pan gasket leaks. Come on BMW, there must be better gasket material that can sustain heat and oil, gasoline and coolant mix in

[G35POPPEDMYCHERRY]

Originally Posted by HPIA4v2

Damn, BMW has not fixed this issue since N52, N54, N55 engines; all has oil pan gasket leaks. Come on BMW, there must be better gasket material that can sustain heat and oil, gasoline and coolant mix in

lmaoo my e90 leaks oil like clock work....oil housing every 2 years with the occasional valve cover gasket... what a joke

[pbar]

Originally Posted by G35POPPEDMYCHERRY

lmaoo my e90 leaks oil like clock work....oil housing every 2 years with the occasional valve cover gasket... what a joke

But with new technology, it can now cost you $4000 to replace!

[G35POPPEDMYCHERRY]

Originally Posted by pbar

But with new technology, it can now cost you $4000 to replace!

I know others cars leak oil. But damn BMW stay leaking oil

[HPIA4v2]

I'll watch this like a hawk, any sign of leak I am bringing mine in under warranty. No way I am paying $4000 after warranty expires


my OFH/oil cooler gaskets weep a bit on my N55 E92 335i, dealer did it under warranty; I insisted on my SA to do it before it got worsen and good thing he agreed.
My 535i N54 leaked VC, OFH, oil-cooler now oil-pan gaskets, $1200 to get oil pan alone done; the sub-frame and active hydraulic anti roll need to be taken out before tech can drop the pan to put new gasket. I have done all DIY but not sure I want to put the engine on crossbar while the sub-frame is removed and I am under the engine.

Just pressure wash my N63 V8 engine last night cause the smell of burnt oil start to permeate to cabin, this one has turbo oil return lines leak; they sit right below the turbos so this leak is being broiled everytime you drive. I am done with BMW V8 for now. BTW, I heard the entire front end of the engine needs to be taken apart to fix this on a V8

Soon it's not NHTSA that fine BMW but EPA

[damageprone]

https://f80.bimmerpost.com/forums/sh....php?t=1460218 I wonder if this thread is related to the same issue

[maniz]

OP, any updates? It's been over a month since you posted. Hoping all is well now? Let us know what the root cause turned out to be. Thank you.

[M4drift]

Sorry for lack of reply, have been off the radar for a while as work has been bananas. It all boils down to this, the car went in to check for an intake air leak prior to having any issues, when the crank case ventilation system was pressurized it locked up the internal crank case breather check valve in the valve cover. This quickly over pressurized the system and created a leak at the rear main seal. It was never the oil pan, we removed and replaced the gaskets for absolutely no reason what so ever. The leak looks like its coming from the back of the pan but it's actually a sort of unintentional weep hole where a rear main seal leaks from.

Pulled off trans, replaced rear main seal, replaced engine cover, problem solved. BMW swears the crank case pressure testing had nothing to do with it but cause and effect is cause and effect in my eyes. Since then absolutely no issues, however I have probably put 2K miles on it in the last year, if that. It also lived at the dealer for almost 6 weeks during this process.

I have several cars and so this one sits a lot of the time, ie if it's raining, or windy, or dusty, or winter, etc.

Hope this helps shed some light on this issue, the oil pan gasket is pretty robust, not likely to leak easily compared to previous models.