Crankcase seperation causing oil leak?

335speed · 10-22-2013, 06:33 PM

I took my 07 335i with 90k miles into my indy shop for a growing oil leak. I replaced my valve cover gasket yesterday and fixed that leaking but I still had oil pooling under my car after it reached running temps. According to my mechanic the leak is coming from an internal source and is visible at the right side of the crankcase. He showed me a bulletin about the magnesium and aluminum parts of the crankcase separating and causing an oil leak and insisted it was probably that. I was wondering if any of you have dealt with this issue before or if those symptoms can be caused by another issue.

123Britt · 10-23-2013, 12:11 PM

I did not think that the N54 was made with the lighter mag due to heat.
.
I would check the Bentley or other source -- I think only the non-turbo engines(N52) were made uising the 2 materials. Could be wrong??

335speed · 10-23-2013, 07:21 PM

Quote:

Originally Posted by 123Britt

I did not think that the N54 was made with the lighter mag due to heat.
.
I would check the Bentley or other source -- I think only the non-turbo engines(N52) were made uising the 2 materials. Could be wrong??

The bulletin says its for the n52 n51 n51k engines so id be inclined to believe you. I cant even find the bulletin online. it is bulletin SI B 11 08 09 in case anyone can pull up more information.

raceyBMW · 10-24-2013, 12:01 PM

N54 has a plastic/composite valve cover and 100% aluminum blocks with iron sleeves, no magnesium to be found on the N54, so your mechanic is wrong. It is very likely that the leak is coming from the oil filter housing gasket that separates it from the block.

Are you sure its oil? If you have Auto tranny, then it could be the mechatronic sealing sleeve leaking, its known issue.

F32Fleet · 10-24-2013, 12:29 PM

The N54 is an aluminum or Al-alloy block. 100% sure on this.

335speed · 10-25-2013, 12:42 AM

Good to know about the composition of my block. Thanks for that good to know I don't need an entire crankshaft. I took it to a BMW specific shop, biggest I've ever seen. Told me they were pretty sure it was the oil pan gasket leaking. Thanks for the follow up guys.

Red_Bean_Bun · 10-25-2013, 01:18 PM

+1 on the oil filter housing .......

Quote:

Originally Posted by raceyBMW

N54 has a plastic/composite valve cover and 100% aluminum blocks with iron sleeves, no magnesium to be found on the N54, so your mechanic is wrong. It is very likely that the leak is coming from the oil filter housing gasket that separates it from the block.

Are you sure its oil? If you have Auto tranny, then it could be the mechatronic sealing sleeve leaking, its known issue.

10-22-2013, 06:33 PM	#1
335speed Private First Class 13 Rep 193 Posts Drives: 16 550 Join Date: May 2013 Location: SoCal iTrader: (0) Garage List 2007 BMW E90 [10.00]	Crankcase seperation causing oil leak? I took my 07 335i with 90k miles into my indy shop for a growing oil leak. I replaced my valve cover gasket yesterday and fixed that leaking but I still had oil pooling under my car after it reached running temps. According to my mechanic the leak is coming from an internal source and is visible at the right side of the crankcase. He showed me a bulletin about the magnesium and aluminum parts of the crankcase separating and causing an oil leak and insisted it was probably that. I was wondering if any of you have dealt with this issue before or if those symptoms can be caused by another issue.
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10-23-2013, 12:11 PM	#2
123Britt Captain 308 Rep 873 Posts Drives: 15 M235i AT; 2008 Z4 3.0Si MT Join Date: May 2008 Location: Madison, Alabama iTrader: (0)	MAG & ALUM I did not think that the N54 was made with the lighter mag due to heat. . I would check the Bentley or other source -- I think only the non-turbo engines(N52) were made uising the 2 materials. Could be wrong??
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10-24-2013, 12:01 PM	#4
raceyBMW king of the hills 112 Rep 2,923 Posts Drives: 2011 M3 w/ESS55, 2001 540i/6 Join Date: Dec 2006 Location: Arvada, CO iTrader: (1) Garage List 2001 BMW 540i/6 [8.17] 1994 530i [9.00] 2007 335i Coupe [8.37]	N54 has a plastic/composite valve cover and 100% aluminum blocks with iron sleeves, no magnesium to be found on the N54, so your mechanic is wrong. It is very likely that the leak is coming from the oil filter housing gasket that separates it from the block. Are you sure its oil? If you have Auto tranny, then it could be the mechatronic sealing sleeve leaking, its known issue. Last edited by raceyBMW; 10-24-2013 at 03:40 PM..
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10-24-2013, 12:29 PM	#5
F32Fleet Lieutenant General 3908 Rep 10,606 Posts Drives: 2015 435i Join Date: May 2005 Location: Southeastern US iTrader: (0)	The N54 is an aluminum or Al-alloy block. 100% sure on this.
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10-25-2013, 12:42 AM	#6
335speed Private First Class 13 Rep 193 Posts Drives: 16 550 Join Date: May 2013 Location: SoCal iTrader: (0) Garage List 2007 BMW E90 [10.00]	Good to know about the composition of my block. Thanks for that good to know I don't need an entire crankshaft. I took it to a BMW specific shop, biggest I've ever seen. Told me they were pretty sure it was the oil pan gasket leaking. Thanks for the follow up guys.
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