[BackyardMechanic]

Was losing around a quart over 2 weeks time I am pretty sure this is the culprit anyone have any idea what part this is and what steps to take to replace it 2006 330i sedan

[BackyardMechanic]

I have just checked realoem and I see that this is just a mounting point for the water pump and not where the oil is leaking from if anyone has any ideas where it could be coming from please let me know

[lookalikehuuh]

Its most likely coming from either the oil pan gasket, valve cover gasket or Oil Filter Housing gasket.

[3PedalJake]

Pull your engine vanity cover off and check the right front corner of the engine just about behind where the radiator hose to the reservoir tank passes. I have 2 2006 E90s and both of them had the infamous broken head bolts in the timing chain area, and that's just where it was leaking to. Hoping for your sake it's just the valve cover gasket because it's quite a job replacing them.

[lookalikehuuh]

Originally Posted by 3PedalJake

Pull your engine vanity cover off and check the right front corner of the engine just about behind where the radiator hose to the reservoir tank passes. I have 2 2006 E90s and both of them had the infamous broken head bolts in the timing chain area, and that's just where it was leaking to. Hoping for your sake it's just the valve cover gasket because it's quite a job replacing them.

That does NOT look fun... I guess since those bolts are aluminum hopefully they were easier to get that easy out drilled into them.

[3PedalJake]

Originally Posted by lookalikehuuh

That does NOT look fun... I guess since those bolts are aluminum hopefully they were easier to get that easy out drilled into them.

They were easy to extract, spun them out with my fingers. It's getting to them that's the challenge. Involves a VCG job just to get near them, then locking the crank and cam and pulling the Vanos gears. After that it's easy lol

[BackyardMechanic]

thanks for the responses I just did the valve cover gasket last month and as for the ofhg its never been done to my knowledge I am gonna check the the front right really hope that's not the case but oh well

[3PedalJake]

If you never did the ofhg it's on borrowed time anyway since they are from the moment they're installed, may as well just for PM if nothing else and rule it out since thats a 30 minute $15 job. Shame you didn't check the bolts while you were in there but how to know. I did the same then had pull it right back off again.

[3PedalJake]

Oh and if you do end up back in there don't be fooled by a bolt with the head just resting lazily on top of the bolt, one of mine was missing (found in oil pan later), one was lodged precariously half way down the chain well and one was just sitting there on top of it's bolt looking up innocently at me.

The circled one was wedged between the block and chain guide, the one lower left of it was just sitting there looking intact.

[BackyardMechanic]

What was the mileage on your e90s when you figured out the head bolts were broken ?
Is this a problem that happens with age?

[StradaRedlands]

Originally Posted by BackyardMechanic

thanks for the responses I just did the valve cover gasket last month and as for the ofhg its never been done to my knowledge I am gonna check the the front right really hope that's not the case but oh well

OFHG is a super easy job... If you have any residue around it, just do it. I'd recommend doing the Mickey Mouse Flange and the accessory belt/tensioner at the same time while you're there. Take a good look at the upper radiator hose as well, it might be seeping around the overflow nipple. Good luck at that point!

[3PedalJake]

Originally Posted by BackyardMechanic

What was the mileage on your e90s when you figured out the head bolts were broken ?
Is this a problem that happens with age?

Yes both mine are long in the tooth, both craigslist multi owner specials. The 330i was over 200k miles and the 325i around 190k. Not sure age has any bearing though cause if you google "BMW N52 broken head bolt" you see it start popping up around 2008. I think either a bad batch of bolts or overtorqued at the factory. These stretchy aluminum bolts are kinda iffy on a good day IMO.

[BackyardMechanic]

Here are a couple photos is this the right area to look at just to the right of the vanos solenoids ?

[3PedalJake]

It's hard to tell when there's so much oil there but encouraging that it's that high up cause the broken bolts leak at the junction of the block to the head. They're not really "head bolts" IE clamping force over the combustion chambers, it's what would be the timing cover if it wasn't all one piece but they're in the head so that's just what they get called. I would degrease it as much as you can and change the ofhg and see what happens.

[BackyardMechanic]

Thanks for the help ended up replacing the ofhg and I am pretty certain that was the culprit.

[StradaRedlands]

Originally Posted by BackyardMechanic

Thanks for the help ended up replacing the ofhg and I am pretty certain that was the culprit.

Yeah, that's gonna' need to be replaced!