[Unklejoe]

So, I just picked up my 2011 335i and got to reading on the forums.

Apparently, there are some isolated cases of the VANOS sprocket bolts (the 4 bolts that hold the sprocket to the rest of the unit) shearing off on N55 cars produced before 2011 (mine was 10/10).

See: http://www.e90post.com/forums/showth...=905962&page=7

I have a CPO warranty but I have done some light mods so I don't want to assume that it will cover a replacement engine if one of these VANOS bolts were to shear off and go where it is not supposed to.

My question is:

Has anyone replaced the VANOS adjustment units as a preventative measure?

OR:

Has anyone replaced the actual VANOS sprocket bolts that are subject to shearing off? If so, what size are the bolts and are they reverse threaded? Can it be done without removing the adjustment units and timing chain?


Also:

How many people have actually had this happen?

I wonder if ALL pre 2011 N55 are effected or if there is a mixture of bad bolts and good bolts throughout those production months.


Would hate to have this motor explode in the car I just paid $31,000 for. I would be forced to put an LS2 and a 4l80E in this car rather than spend 6k for a junkyard motor!
Thanks

[JETmn]

I was thinking about this too. I have heard several cases of it happening, even on a bone stock car. If the bolts are accessible then we should be able to replace them one at a time and not knock anything out of adjustment. I have not looked in to the actual process very much though to see if that is feasible.

[Unklejoe]

Originally Posted by JETmn

I was thinking about this too. I have heard several cases of it happening, even on a bone stock car. If the bolts are accessible then we should be able to replace them one at a time and not knock anything out of adjustment. I have not looked in to the actual process very much though to see if that is feasible.

I tried looking around for detailed pictures of the VANOS units with the valve cover off, but all I could find were some pictures from the service manual.

It looks like they MAY be accessible with the valve cover off without having to remove the unit as a whole. I know it is a TORX head bolt, probably about 1.5cm long, but that's it. There are pictures floating around on some other forum. If this were possible, you could definitely do each bolt one at a time and not have a problem.

The exhaust cam seems to have some sort of casing around it which may prevent the bolt from being able to unscrew all the way.

Worse case is you have to unbolt the unit from the cam. It doesn't seem like an extremely difficult procedure, but I would rather not. Seems like we might be able to get away with just removing the tensioner bolt and swapping the unit without having to remove the timing chain. We will need the alignment tool though so we could line up the trigger wheel.

Anyone have detailed pictures of the back side of the VANOS units?

On a side note, it is pretty pathetic for BMW to be making these kinds of mistakes. Seriously. This was a problem on the E46 M3 too apparently. You think they would learn from their stupid mistakes. This is supposed to be some precision expert engineering yet they cut corners to the point of using "hollow" bolts.

I don't want to hear any crap about how they sourced the bolts from a manufacturer and they didn't meet BMW's expectations either. That's what they tried saying about the HPFP issues (that still plague us 2011 N55 suckers).

Where is the quality control?

My Maxima had variable valve timing (CVCT) in 2002 (same exact thing as VANOS) and there was not a single problem with it. Sold the car with 206k miles and it never had any issues. No solenoid failures. No bolts flying off. NADA.

LEARN FROM YOUR MISTAKES BMW.

Sorry about the rant. I am just extremely pissed off that I have to mess around with the timing components of my $XX,XXX new BMW motor to fix an issue that could have been avoided by spending 84 cents on some better hardware.

[Markus8291]

I wonder how many cases it would take in order to take this as far as forcing bmw to warranty the vanos system for 1xx,xxx miles like they did with the fuel pump in the n54's...

[Unklejoe]

Originally Posted by Markus8291

I wonder how many cases it would take in order to take this as far as forcing bmw to warranty the vanos system for 1xx,xxx miles like they did with the fuel pump in the n54's...

It would probably never happen. This only seems to apply to N55s produced before Jan 2011, so the numbers probably wouldn't be high enough to make a blip on their radar. I was unlucky enough to get one made in October.

Even worse yet is that in 2012, the N55 went to a completely new fuel pump design. So I am willing to bet that the "HPEP" pump is the newest revision we will ever see. They obviously have up.

But then again, maybe they will issue a recall for the VANOS considering it is such a small number of cars (and this IS a safety concern after all).

But I would rather not wait to see lol.

It's a shame. I love everything about this car. If it weren't for this VANOS problem and the HPFP, it would be considered an extremely reliable platform if you ask me.

[Markus8291]

Originally Posted by Unklejoe

It would probably never happen. This only seems to apply to N55s produced before Jan 2011, so the numbers probably wouldn't be high enough to make a blip on their radar. I was unlucky enough to get one made in October.

Even worse yet is that in 2012, the N55 went to a completely new fuel pump design. So I am willing to bet that the "HPEP" pump is the newest revision we will ever see. They obviously have up.

But then again, maybe they will issue a recall for the VANOS considering it is such a small number of cars (and this IS a safety concern after all).

But I would rather not wait to see lol.

It's a shame. I love everything about this car. If it weren't for this VANOS problem and the HPFP, it would be considered an extremely reliable platform if you ask me.

Build date on mine is 7/2010 so I have the same problem. I hate driving around with that in the back of my mind. My HPFP has already been replaced under warranty but the Vanos problem could be a lot more costly, especially out of warranty (which mine is in August) Maybe bombarding BMWNA with letters about this "safety concern" is worth a shot, at least to find out where they officially stand on the issue...

[Unklejoe]

Originally Posted by Markus8291

Build date on mine is 7/2010 so I have the same problem. I hate driving around with that in the back of my mind. My HPFP has already been replaced under warranty but the Vanos problem could be a lot more costly, especially out of warranty (which mine is in August) Maybe bombarding BMWNA with letters about this "safety concern" is worth a shot, at least to find out where they officially stand on the issue...

Yeah, anything is worth a shot.

I know they know about this issue too. There is a SIB about it that specifies the years impacted by the bad bolt issue.

I am going to try and get the dealer to update my DME to the newest version so I will run it by them when I go.

I don't expect them to do much for a problem that has not occurred yet though.

Still waiting for pics of the VANOS sprockets with the valve cover removed if anyone has them. It would be a tremendous help. The ability to swap the bolts without messing with the timing could turn this 4+ hour job in to a simple quick fix.

[Markus8291]

Originally Posted by Unklejoe

Yeah, anything is worth a shot.

I know they know about this issue too. There is a SIB about it that specifies the years impacted by the bad bolt issue.

I am going to try and get the dealer to update my DME to the newest version so I will run it by them when I go.

I don't expect them to do much for a problem that has not occurred yet though.

Still waiting for pics of the VANOS sprockets with the valve cover removed if anyone has them. It would be a tremendous help. The ability to swap the bolts without messing with the timing could turn this 4+ hour job in to a simple quick fix.

Let me know what you find! I'd love to get this "resolved" as well so I have peace of mind.

[Markus8291]

I'm not technical enough but it's not anywhere in the technical training document posted here:

http://www.e90post.com/forums/showthread.php?t=846407

[Unklejoe]

Originally Posted by Markus8291

I'm not technical enough but it's not anywhere in the technical training document posted here:

http://www.e90post.com/forums/showthread.php?t=846407

Yeah that's where I got the picture above from.

That document is referred to as a service manual but it's more like a datasheet.

[MooreBoost]

How can you determine the build date?

Edit - realoem.com

[Dconnelly9191]

Originally Posted by garrettmoore

How can you determine the build date?

Edit - realoem.com

I'd Like to know this aswell.

[MooreBoost]

Go to realoem.com.

[Markus8291]

Originally Posted by Dconnelly9191

I'd Like to know this aswell.

the build date (month and year) is also located on the sticker you see when opening the driver side door.

[Jec1]

Gentlemen:

Very active concern on my mind in terms of threats to long term ownership of this car. N55s with build dates of March 2010 through December 2010 are affected with the old Vanos bolt design prone to shearing.

For those who have had the bolts fail, the replacement part pursuant to the sib is a revised design, less prone to failing. I have spoken with my SA several times about this issue, with the n55 being a workhorse he has seen many failures across model ranges, but if memory serves me correctly from my discussion, only one x5 that had an issue with the revised part. This failure from what I recall was speculated to be due to a number of other ongoing issues with that particular vehicle and can't solely be attributed to vanos bolts. In short, it looks the engineered fix has statistically resolved the issue from what my dealership has seen.

The revised bolts cost approximately $600 in parts from my understanding; dealer labor hours I haven't had quoted yet. I'm actively anticipating replacing the bolts even if everything is running smooth shortly before expiration of my CPO if I keep the car, but I have another couple years for that.

Out of warranty cost if they shear was quoted to me at about $4-5k plus the risk of more significant engine damage from bolt chunks running through your engine. I don't know how significant a job replacement with the revised part is, but I know it has minimized the shearing issue which has been represented to me as being quite prelavent among pre 12/10 production n55 engines.

I'll pull the revised part no's from my file when I get home-hope this helps. J

[Sidnito]

yeah this nightmare just happened to me this week!
mines a 08/10 build n55 and I'm screwed. stupid warranty said the bolts are considered hardware not needed for the VANOS. it just supports it. such BS and I don't see why BMW doesn't do anything about it!
$4200 it is costing me! money I do not have.

[Jec1]

Originally Posted by Sidnito

yeah this nightmare just happened to me this week!
mines a 08/10 build n55 and I'm screwed. stupid warranty said the bolts are considered hardware not needed for the VANOS. it just supports it. such BS and I don't see why BMW doesn't do anything about it!
$4200 it is costing me! money I do not have.

To confirm, you are under bumper to bumper warranty still and your dealer is attempting to deny a warranty repair? I think you need to find another dealer my friend...my understanding is this is absolutely a covered item, under 4/50k warranty or under cpo. Best, J

[Sidnito]

it's another warranty that the dealership sold me due to the car at 60k miles, being outside CPO when I got it. I'm using enterprise financial group

[Jec1]

You should still be under your 4 year 50k bumper to bumper warranty...use that warranty for coverage. If production was in August, you probably have an in service date of October or so...meaning unless you've exceeded 50k miles you still have your original factory warranty.

[Sidnito]

Originally Posted by Jec1

You should still be under your 4 year 50k bumper to bumper warranty...use that warranty for coverage. If production was in August, you probably have an in service date of October or so...meaning unless you've exceeded 50k miles you still have your original factory warranty.

yeah that's the thing I'm at 85k miles

[cialz]

at least this isn't as bad the intermediate shaft bearings RMS / IMS in 911 motors

[Jec1]

Originally Posted by Sidnito

yeah that's the thing I'm at 85k miles

Just saw your post in the other thread. Sorry abt that man...this is a known design flaw. I wouldn't be so quick to give up on warranty coverage, especially if the dealer sold you this policy with the representation that it mimics cpo coverage in some fashion.

As an aside, holy mama that's a lot of miles for a 2011