Snapped Bolt

[hemi6]

I recently replaced my oil filter housing gasket as I was getting a puddle of oil near the cylinder head and flowing down the block. So I was looking over that area yesterday and noticed a puddle and something I had not noticed before, there is a bolt head on the part which the oil filter housing bolts to (looks like the cyl. head) that is snapped-off. I am guessing this is the cylinder head, anyone know what this bolt does (why is it there). if the bolt head is snapped off would this cause an oil leak? Its an 2010 328Xi wagon, the bolt is right under the 1st intake runner.

[marvinstockman]

Show picture to a mechanic.

You can also post on:

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[JDStrickland]

I cannot see this very well, but it appears to not be a bolt that is used to hold the oil filter housing on. But, the basic right answer is, yes a broken bolt can be the cause of an oil leak. Any bolt that holds the oil filter housing to the engine should be perpendicular to the mating surfaces, the bolt you took a picture of looks to be parallel, this means that I think it would be some sort of plug that they put in after machining an internal passage.

- - - Updated - - -

https://www.realoem.com/bmw/enUS/sho...diagId=11_3867

The objects of your desire are shown here as Items 6, 7, and 8.

[hemi6]

Figured it out, its a common issue. BMW used aluminum head bolts, over time and many heat cycles later this one in particular has a tendency to snap creating an oil leak:

https://www.youtube.com/watch?v=LF9kJCGRGaM

It came right out using this guys method, just waiting on a new bolt.

Mike