Dreaded Alternator Bracket Oil Leak

Is there an improved gasket or other sealing method that can be used when fixing the oil leak behind the alternator bracket? The car only has 55K miles, so I would prefer this repair to last a little longer if possible.

Any information about the failure mode for the gasket? Is it brittle, melted, or misformed? It would seem that a gasket made of the correct material would last a long time in this application.

Take it from a person who's actually taken the time to DIY it. I actually did it on my E60 545i (N62) but the E65 750 (N62N) has the same engine block. Make no mistake about it, the replacement process is a PITA!!! The gasket behind the bracket becomes rock-hard and brittle. Loses its pliability basically and I had to pick it out of the groove. Along with a brand new gasket, I used some Permatex Oil resistant silicone sealer around it to help it along. The stealer will quote you anywhere from $1200 - 1600 to replace the $3.27 gasket. I couldn't swallow that pill thus the reason for me DIY'ing it. Good luck.

+1, mine was brittle and extremely hard, and definitely headache to get to.

Sent from my ADR6425LVW using Bimmer App

Originally Posted by coole65i

The stealer will quote you anywhere from $1200 - 1600 to replace the $3.27 gasket. I couldn't swallow that pill thus the reason for me DIY'ing it. Good luck.

thats more like a suppository not a pill..lol

Yeah, I am getting a daily oil leak, too. I guess I will have to take it to an Indy here in Houston. I don't know if I can do it myself.

From these responses of the gasket being hard and brittle it sounds like the elastomer doesn't have enough heat resisitance for the application.

It is probably made from Buna-N which is oil resistant and has a temperature range of -40 to 250 F. This is the most common elastomer used for o-ring and gaskets since it is inexpensive.

Not sure what temperature the block is at the point the gasket seals to the block, but it must be higher or right at 250 F.

A silicone or Viton gasket would have been a better choice since it is oil resistant and has a higher temperature rating of 400 F. I going to see if I can find or make a silicone or Viton replacement gasket.

Too bad BMW didn't do this, it would probably have been about $.05 more than the buna-n gasket.

Use the BMW gasket, & just add some extra silicone for good measure. This is a 8 to 10 job, that you only want to do 1 time!

Use permeatex o ring sealant. This is the same as Honda sealant and will make the gasket last forever

Any one have the part # for the gasket I ended up with the wrong one.

Originally Posted by Rookie2008

Any one have the part # for the gasket I ended up with the wrong one.

Part #12317512327......Which one did you get?

12317507996 Thank you

Originally Posted by Rookie2008

Any one have the part # for the gasket I ended up with the wrong one.

The part number is 12317507807 without oil cooler (GULF VERSION = No (L822A = No)

The part number is 12317507808 with oil cooler (GULF VERSION = Yes (L822A = Yes)


Part #12317512327 is for 760 models

I have a water cooled an NO oil cooled thanks guys

I get this number! 12317507807

http://bmwfans.info/parts/catalog/E6...ounting_parts/

http://parts.bmwofsouthatlanta.com/s...&searchString=

Water cooled

http://parts.bmwofsouthatlanta.com/s...&searchString=

I saw the you tube video that explains that the gasket is a problem but does not give a DIY about how to gain access, disassemble anf reassemble. Has anyone doen a DIY on the process?

Originally Posted by 745Li31404

I saw the you tube video that explains that the gasket is a problem but does not give a DIY about how to gain access, disassemble anf reassemble. Has anyone doen a DIY on the process?

Have not found a specific DIY for the alternator bracket oil leak.

The video and this thread http://www.bimmerfest.com/forums/sho...d.php?t=417251 at post 22 and starting again at post 53 give you a pretty good idea on how to accomplish the job.

Good find. A little deeper that I was hoping for but will be very useful if I decide to tackle it on my own. THANKS!

Originally Posted by coole65i

Take it from a person who's actually taken the time to DIY it. I actually did it on my E60 545i (N62) but the E65 750 (N62N) has the same engine block. Make no mistake about it, the replacement process is a PITA!!! The gasket behind the bracket becomes rock-hard and brittle. Loses its pliability basically and I had to pick it out of the groove. Along with a brand new gasket, I used some Permatex Oil resistant silicone sealer around it to help it along. The stealer will quote you anywhere from $1200 - 1600 to replace the $3.27 gasket. I couldn't swallow that pill thus the reason for me DIY'ing it. Good luck.

Can I use a floor jack to lift the engine or do I need an engine hoist? Also, do I need to remove both front engine mount bolts or just the side I am working on?

N303CB

Do I need to loosen both front engine mounts to raise the engine enough to get to the alternator mount? Also, can I use a floor jack to raise the engine or do I need an engine hoist?

Thanks

Originally Posted by N303CB

Do I need to loosen both front engine mounts to raise the engine enough to get to the alternator mount? Also, can I use a floor jack to raise the engine or do I need an engine hoist?

Thanks

did mine couple months back...dont need to release both mounts only one and i used floor jack to raise/lower the engine to gain access to rear 2 bolts,take off the wheel so you have easy access...

here is a little video i made before putting it all back together......also i used silicone rtv gasket maker and no leaks of any kind...

Thank you.

Thanks for the video. In the video, you had an o-ring laying around the pulley on the table. What is that o-ring?

Originally Posted by N303CB

Thanks for the video. In the video, you had an o-ring laying around the pulley on the table. What is that o-ring?

that o-ring was extra that came with alternator,but alternator already had o-ring on it..its used to seal the connection between alternator and alternator housing so its water tight...