Massive 4.8L Oil Leak - See Picture - Help Needed

[juthale]

My 4.8L dumped 4 liters of oil in less than 5 miles yesterday. Bless my wife's heart, she obeyed the computer and stopped driving immediately when the critically low oil warning appeared. The car is back home over the pit, and now I'm trying to sort out exactly what the source of this leak is.

When the engine is running, oil comes in a steady stream from between the engine and the front differential (driver's side of the engine). From below, looking up between the differential and the engine, the leak is higher up than I am able to see - above the highest visible mounting bolt for the dif (see photo). I am unable to see the area of the leak from the front of the engine. I've removed the inner fender, but can't see it from the wheel well. I've removed the intake and the air dam and just about every other reasonably easily removed part, but I can't see it from above. There seems to be no easy way to get eyes on the leak.



Two questions for the experts:

1. Any thoughts on what might be the source of such a prolific leak in this area?

2. Any ideas on the easiest way to get in for a better view of what's above the differential?

I'm a licensed mechanic, so I'm not worried about doing whatever is needed, but I'd really love to avoid any more unnecessary disassembly as I try to sort out what the problem is.

Thanks in advance!

Justin

[e30cabrio]

That is scary, I have no idea, I'm glad the motor was not ruined, I hope you sort it easily & welcome!

[juthale]

Thanks e30cabrio. I've been a longtime lurker here on these threads and have found a lot of great info here over the years, but this one finally forced me to join

Yes, I' very grateful my wife shut the engine down immediately. I have heard of others who were not so fortunate. I don't mind doing a lot of work to fix an oil leak, but a total engine rebuild is another matter altogether!

Oh, and I should have mentioned... it's a 2008 E70, 4.8L with the cold weather and sport packages.

Thanks again!

[gregg3gs]

Alternator bracket gasket. Also the gasket to nowhere.

[juthale]

Originally Posted by gregg3gs

Alternator bracket gasket. Also the gasket to nowhere.

Thanks again, gregg3gs; you nailed it. Gasket was cracked. What a royal pain to get at!!!

For those who are watching a slow drip, don't put it off. I made a note about a small leak at my last oil change, which was less than 2k miles ago. Given how dramatic the leak was, I feel very fortunate to not be doing a full engine rebuild. As catastrophic a leak as I have ever seen. It was literally a stream coming out, not drips.

Also, I did manage to get this done without lifting the engine, dropping the sub-frame, or pulling the front differential. I used a ground down socket, reduced to 1/4" drive. No universal joint either. Just a short 1/4" drive extension (see picture). Still a terrible job, but not nearly as bad as hoisting the engine and separating the front drive gearbox.



Good luck to you all. Let me know if you have any questions. And thanks again for those with the expertise to point me in the right direction.

If you're taking this job on, check out this Pelican BMW tech article. I found it very useful.

Originally Posted by asma123

Make sure the hoses that go to the oil cooler are nice and tight.. those will leak out all the oil very fast.

Thanks for this as well. Going to put all new O-rings in all of the tube joints and will double-check they are secure.

Cheers!

[Ron07x5]

Originally Posted by juthale

Thanks again, gregg3gs; you nailed it. Gasket was cracked. What a royal pain to get at!!!

For those who are watching a slow drip, don't put it off. I made a note about a small leak at my last oil change, which was less than 2k miles ago. Given how dramatic the leak was, I feel very fortunate to not be doing a full engine rebuild. As catastrophic a leak as I have ever seen. It was literally a stream coming out, not drips.

Also, I did manage to get this done without lifting the engine, dropping the sub-frame, or pulling the front differential. I used a ground down socket, reduced to 1/4" drive. No universal joint either. Just a short 1/4" drive extension (see picture). Still a terrible job, but not nearly as bad as hoisting the engine and separating the front drive gearbox.



Good luck to you all. Let me know if you have any questions. And thanks again for those with the expertise to point me in the right direction.

If you're taking this job on, check out this Pelican BMW tech article. I found it very useful.



Thanks for this as well. Going to put all new O-rings in all of the tube joints and will double-check they are secure.

Cheers!

Getting.into this soon

[gregg3gs]

Originally Posted by juthale

Thanks again, gregg3gs; you nailed it. Gasket was cracked. What a royal pain to get at!!!

For those who are watching a slow drip, don't put it off. I made a note about a small leak at my last oil change, which was less than 2k miles ago. Given how dramatic the leak was, I feel very fortunate to not be doing a full engine rebuild. As catastrophic a leak as I have ever seen. It was literally a stream coming out, not drips.

Also, I did manage to get this done without lifting the engine, dropping the sub-frame, or pulling the front differential. I used a ground down socket, reduced to 1/4" drive. No universal joint either. Just a short 1/4" drive extension (see picture). Still a terrible job, but not nearly as bad as hoisting the engine and separating the front drive gearbox.



Good luck to you all. Let me know if you have any questions. And thanks again for those with the expertise to point me in the right direction.

If you're taking this job on, check out this Pelican BMW tech article. I found it very useful.



Thanks for this as well. Going to put all new O-rings in all of the tube joints and will double-check they are secure.

Cheers!

Can you add pictures.
This is an expensive repair at any repair shop. I would certainly like to see how you were able to access the gasket.

[SeanC]

Originally Posted by gregg3gs

Can you add pictures.
This is an expensive repair at any repair shop. I would certainly like to see how you were able to access the gasket.

I second that. Also pic in the OP doesn't show for some reason.

[juthale]

Thanks gregg3gs. Yes, I read about the "dreaded alternator bracket" in another thread and wondered if that might be it. It's an incredible leak for something so trivial, but I have seen elsewhere failure of the alternator bracket gasket can result in a pretty bad leak.

Is it worth diving in and pulling the alternator, or are there other likely candidates in the same area?

[asma123]

make sure the hoses that go to the oil cooler are nice and tight.. those will leak out all the oil very fast