Massive oil leak on passenger side

[cn90]

- For those who live in L.A. area, try:

Southbay Independent
18020 S Vermont Ave
Gardena, CA 90248
(310) 532-3145
https://www.yelp.com/biz/south-bay-i...dent-gardena-2


- Back to my oil leak, I have a theory, it is likely RMS b/c according to the photo below (courtesy of youtube 50sKid video), if there is a RMS leak, oil will trickle from #1 (RMS), down to #2, then along that long bolt and you will see it at the bottom of the bolt (RED arrows).

- Alternatively, it could leak from ONLY the rear part of the oil pan gasket #2, but why only the rear part of the oil pan gasket?

- I understand that it is not environmentally friendly to have an oil leak, but since this job is sooo big, I'd rather leave it alone and add 1 qt of oil every 2K-3K.

- On a different topic, I did a CCV Mod (a la BavarianE39), which reduced my internal oil consumption (piston ring issue) from 1qt/300 miles down to zero consumption. Interestingly, this mod increases crankcase vacuum and supposedly air is sucked in from outside ---> the RMS ---> into the engine, which may reduce RMS oil leak (if it is truly RMS leak). You can see my CCV Mod in thread #164 below.
I drove the 2004 X3 2.5i for 700 highway miles, there were a few drops of oil seen at that long bolt, but oil dipstick stayed FULL for 700 miles.

https://xoutpost.com/bmw-sav-forums/...oblems-17.html



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[Attacking Mid]

I think I have the same leak. A trick I learned from the X3's is to go around and tighten the oil pan bolts just a little. I did this on my N52 (X3) and it noticeably reduced the oil drippage. I just did this on my E53, so it's too early to tell if it did any good or not.

AM.

[andrewwynn]

I think RMS too high to leak when not running. I like the thought of increase crankcase vacuum to make leaks go inward vs outward.

[Russianblue]

I drove around with a leaky oil pan for 4 years before finally biting the $1200 bullet. That said, my indie was not super enthused about that job (because it's a complete bit*H) and insisted we change the OFHG first. He said he goes left to right, hi to low analyzing m54 leaks. if oil is leaking on the passenger side, start with the valve cover. driver's side...OFHG. If you KNOW both of those gaskets are good (which is not always easy to know without disassembly), the oil pan is likely the next culprit.

I swapped out the VC and OFHG myself. Those aren't terribly difficult. Leaks didn't stop. Had indie do the oil pan. Leaks stopped. In retrospect I probably should have tried the bolt-tightening trick and the CCV mod but I was giving the car to my kid and couldn't have her leaking oil all over friends' driveways.

NOW, during those 4 years, I probably had a dozen different people (BMW friends, mechanics, forum buddies) tell me the same thing I just recommended....OFHG and VCG...but ultimately the pan gasket failure could not be denied. One of the indie mechanic's assistants told me when I took it in that a lot of them leak and it is usually around 100k miles when they start - but some last a lot longer.

[cn90]

The video below shows a very comprehensive review of ALL possible oil leak sources for M54 engine.

Pay attention to time marking 2:45 where the person discussed the RMS, note the particular bolt I mentioned in earlier threads? It is wet with oil in the video. So I am very convinced that the oil at that particular bolt is from a RMS leak. If you do the CCV Mod, then it keeps the leak down to a minimum.

HTH.

https://www.youtube.com/watch?v=TyTL8wosXKo

[Don Nguyen]

Interesting that you mention that long oil pan bolt on the back, cause I did notice that same bolt on my car looked like it was soaked in oil and was providing a path for the oil to make its way down.

Got underneath my car again to look at everything yesterday. Didn't take pictures of it this time, but inspecting everything again, it looks like there are areas around the oil pan gasket that has oil stains that goes up roughly .5" on the engine block and then stops. I am seeing/noticing this happening where the passenger axle bolts to the oil pan and also around the back passenger side corner of the oil pan before it attaches to the transmission.

It very well could be both my RMS and oil pan gasket leaking at the same time, but since they are kind of independent of each other, it doesn't hurt to just do one first before the other.

For those who simply tightened the oil pan bolts, what torque value did you tighten it to? Stock specs or something slightly tighter? I'll try this first, since it's something that's easy enough. If I have to do the oil pan gasket, then I'll most likely try it using the cutting the gasket method to save some time, since it seems like it's worked fine for those who have done it before.

One other thing I should note. When I did my VCG, I did notice that it had a large crack/hole that had been previously repaired with some RTV. So I replaced the valve cover along with the gasket at the same time. I am thinking that maybe the now increased pressures from the non-cracked cover could have ultimately ended up causing the leaks to all of a sudden start appearing at the same time.

[andrewwynn]

Originally Posted by Don Nguyen

For those who simply tightened the oil pan bolts, what torque value did you tighten it to? Stock specs or something slightly tighter? I'll try this first, since it's something that's easy enough. If I have to do the oil pan gasket, then I'll most likely try it using the cutting the gasket method to save some time, since it seems like it's worked fine for those who have done it before.

I would recommend stock torque + xx° (say 30° past torqued) I wouldn't know what xx is until I did it. When installing new gasket I use my small impact driver set to hand tight skipping to every 3rd bolt going around 3x until every one is snug then I go around with torque wrench. 6mm bolts are pretty stretchy so you need to use a torque wrench not just seat of pants wrench.

What do you mean about cut the gasket? Is it a shortcut you can avoid removing the CV? Eg lower not remove oil pan, put the gasket in without removing just lowering the oil pan.

I like the sound of that. RTV to cover the gap.

[Don Nguyen]

Originally Posted by andrewwynn

I would recommend stock torque + xx° (say 30° past torqued) I wouldn't know what xx is until I did it. When installing new gasket I use my small impact driver set to hand tight skipping to every 3rd bolt going around 3x until every one is snug then I go around with torque wrench. 6mm bolts are pretty stretchy so you need to use a torque wrench not just seat of pants wrench.

What do you mean about cut the gasket? Is it a shortcut you can avoid removing the CV? Eg lower not remove oil pan, put the gasket in without removing just lowering the oil pan.

I like the sound of that. RTV to cover the gap.

Yea, I am already weary of tightening such small bolts further, but I guess I won't know until I try it out. What brand oil pan gasket did you get and how much was it?

I haven't fully read up on it yet, but yea, basically some people have made cuts in the oil pan gasket to avoid completely removing the subframe/etc out from the car, saving quite a bit of time. I think CN90 was one of the people who had either done it or was contributing to some of the info for it in the thread I was reading. It seems reasonable enough, since considering there are times where people use RTV (or something similar) only without any gaskets at all. Having just a bit of RTV to seal up the cut areas doesn't seem too bad.

[Russianblue]

Just google "Mudbone BMW oil pan gasket cut".

I think this is the original thread. Apparently it is still a complete PITA and an absolute mess, but is definitely a legit alternative. I thought about doing it on my older X but eventually just ponied up $1200 at the indie.


Andrewwynn...with your amazing ingenuity and tireless problem solving, I nominate you to head up the committee to perfect this process and make it mainstream!!

[andrewwynn]

yeah i would have probably invented that solution if i needed to. i'm pretty sure i'm going to find this is the problem on wife's car. (though it might be the valve cover; a quick look showed no oil on the oil filter housing gasket but some oil around the coil packs, not down to the heat shield though)