[voltron1011]

So, after taking my car in for a leaking main seal http://www.e90post.com/forums/showthread.php?t=316748, the mechanics noticed that one of my head bolts was broken as well, and seeping oil out of the hole.
My car is back at the shop tonight while they try to extract the remaining part of the bolt.
After some research I've found that it seems to be happening to quite a few N52 engines: http://www.bimmerfest.com/forums/sho...d.php?t=280142

[F32Fleet]

That's a good question. I've only heard of maybe 2-3 stories about broken AL bolts from around the valve cover or the head. It's really too early to tell because the 325/330's are just now getting close to 50k miles in mass.

[voltron1011]

This really sucks because I had to delay shipping my car back to Germany.
If this is the case with these stretch-bolts breaking, I'm going to replace them all once I get to Germany. Luckily, I'll have access to a decent auto-hobby shop.

[BK]

I've read this a few times. Is it from over-torquing?

[voltron1011]

Originally Posted by BK

I've read this a few times. Is it from over-torquing?

Either that, or a bad batch of stretch bolts that got past the x-ray inspection.

[prototyp]

I noticed a fresh drip of oil hanging off one of my belly pans recently... shudder.

[subframe]

Scary issue. My warranty expires in 3 months.

[ENINTY]

You mean Valve Cover Bolt. A broken head bolt is much more serious.

[voltron1011]

Originally Posted by ENINTY

You mean Valve Cover Bolt. A broken head bolt is much more serious.

No, unfortunately it's a head bolt.. It's in the front of the engine, right under the intake manifold. It's next to the oil filter mount..
They are removing the manifold to get access to the shank of the bolt, so that they can hopefully EZ-out the rest of the bolt.
I'm not terribly upset about this... I've had the car for over 4.5 years (59,000 miles) and this is the really the only issue with the car that I've had.
Plus, the way I figure it, I'm still ahead of things had I purchased a $3300.00 extended warranty. The same extended warranty that would now be moot now that I'm moving back to Germany.
The one thing that does erk me is that I thought that BMW was building really tough engines, and that the engine would be the least of my problems down the road.

[hotnikks]

My warranty expired July...I'm nervous about this. We need to gather evidence to see how widespread a problem this is. I'm at 44k on a july 05 build. Maybe we should start a poll or new thread about this.

[ENINTY]

Originally Posted by voltron1011

No, unfortunately it's a head bolt.. It's in the front of the engine, right under the intake manifold. It's next to the oil filter mount..
They are removing the manifold to get access to the shank of the bolt, so that they can hopefully EZ-out the rest of the bolt.
I'm not terribly upset about this... I've had the car for over 4.5 years (59,000 miles) and this is the really the only issue with the car that I've had.
Plus, the way I figure it, I'm still ahead of things had I purchased a $3300.00 extended warranty. The same extended warranty that would now be moot now that I'm moving back to Germany.
The one thing that does erk me is that I thought that BMW was building really tough engines, and that the engine would be the least of my problems down the road.

I would think breaking a head bolt would require removal of the head and replacement of the head gasket and you would have serious oil contamination of the coolant. Is it a bolt that actually holds the head to the engine block? Also I can't see using an easyout to remove the head bolt shank. The class of fit for head bolts is pretty tight.

It wouldn't be the first time a BMW engine had subpar head bolts. The early E30 M20 engines used to break head bolts until BMW redesigned them.

[voltron1011]

http://www.realoem.com/bmw/showparts...35&hg=11&fg=15
From this pic with the gasket included, it looks like it isn't exactly a head bolt, Per Se... But, rather a bolt that clamps down the head to the main block. There is no gasket underneath, thus no problems with oil/coolant contamination.
So, ultimately, I may be lucky in that it was that particular bolt that broke.

[ENINTY]

Originally Posted by voltron1011

http://www.realoem.com/bmw/showparts...35&hg=11&fg=15
From this pic with the gasket included, it looks like it isn't exactly a head bolt, Per Se... But, rather a bolt that clamps down the head to the main block. There is no gasket underneath, thus no problems with oil/coolant contamination.
So, ultimately, I may be lucky in that it was that particular bolt that broke.

Voltron, thanks for the info. I wonder if the bolt being exposed to the elements (vs. being inside the valve cover) has anything to do with the failure of it. Considering the age of the car, this could be a latent defect in the design. Aluminum corrodes over time and could weaken the metal to the point it can't take the pressure of holding the head down. Maybe the bolt was not properly coated during manufacture and became corroded, which lead to its failure. Keep us posted. Good luck.

[subframe]

One has to wonder whether (a) the percentage of '06 e90s that ultimately develop this problem will prove to be insignificant, or (b) the percentage will become significant as the fleet of '06 e90s ages. I hope for (a) but there is obviously no way to know at this point.

[voltron1011]

As I mentioned earlier, the timing of this could not be worse. I had to hold up my shipment of the car due to this problem.. Thus, I really didn't/don't have time to try and fight this through the dealership and/or BMWNA. Had I more time, I would have taken it to the dealership and demanded some kind of goodwill replacement by BMWNA.
Now that I'm headed back to Germany, I'm going to keep all my documentation related to this. And, if any other stretch bolts break, I'm taking it directly to BMW. I've got a lot of legal folks that I can turn to once I get there, that can help me out.
There is no reason that head bolts should ever fail on an engine. And if one were to fail, BMW should goodwill the work with no questions asked.

[WILLIE92]

i think i did see oil in my drive way, i blamed my sisters car i will check mine tomm.!!!

[Gregg C]

Was this issue corrected at the factory, should I be concerned ??

[voltron1011]

Originally Posted by Gregg C

Was this issue corrected at the factory, should I be concerned ??

From my research, the bolts were corrected in 2007 when they redesigned the engine for the 328i's... The newer motor was known as the N52KP.

[JBE9006]

Originally Posted by voltron1011

No, unfortunately it's a head bolt.. It's in the front of the engine, right under the intake manifold. It's next to the oil filter mount..
They are removing the manifold to get access to the shank of the bolt, so that they can hopefully EZ-out the rest of the bolt.
I'm not terribly upset about this... I've had the car for over 4.5 years (59,000 miles) and this is the really the only issue with the car that I've had.
Plus, the way I figure it, I'm still ahead of things had I purchased a $3300.00 extended warranty. The same extended warranty that would now be moot now that I'm moving back to Germany.
The one thing that does erk me is that I thought that BMW was building really tough engines, and that the engine would be the least of my problems down the road.

This is the exact bolt that broke on my 06 330i @ 70kmi. To make things worse, when I took it to have the oil changed the service tech said that there was a leak somewhere in the oil pan /rear seal area. The oil leak is bad to the point that I'm having to add a quart every 400 miles.
My question is... What would be the part # for this particular bolt? Would it be under "head bolts"? I usually find parts @ tischer but this one I have'nt been able to figure out.

[Chriztofor]

This happened to me too. Is there a TIS on this? I want to show them that this is a known problem/issue. Luckily I am still under warranty by 3 weeks and 1000 miles!

[Chriztofor]

Can anyone pm or email (Chriztofor@aol.com) your invoice showing it was covered under warranty or good will. Please white out all personal information. Thank you in advance.

[Chriztofor]

Anyone found a TSB/TIS or other service bulletin on the topic? Also can anyone pm/email your invoice without your personal info?