Check Your Serpentine Belt (SIB 11 09 08 - Power Steering Pulley and Subframe)

[euro92]

Did some reading on the power steering pulley making contact with the subframe issue and wanted to share my findings.

What happens? Worst case scenario, engine failure via a series of events involving a damaged power steering pulley, shredded serpentine belt, crank seal, and valves.

How does it happen? Hit a bump hard enough and the inner (closest to the engine) edge of the power steering pulley might come into contact with the subframe.

What does BMW say? SIB 11 09 08
E82, E88 (1 Series) with N54 engine up to 4/08
E90, E92, E93 (3 Series) with N54 engine up to 4/08 except xi models

“If the axle carrier has any sign of contact, then the carrier must be replaced. For E90, E92, and E93 vehicles produced up to 3/19/07 which require replacement of the front axle carrier, the left side engine support (P/N 22 11 6 760 317) must also be installed.”

Front axle support 31116785639 (#1) - I believe this is a revised part
Engine supporting bracket, left 22116760317 (#1) - Note this is the bracket, not the rubber mount.

What else can be done? I'm not sure if there are any real solutions outside of what is advised in the SIB. However, there are some theories...

335is Engine Mounts
The 335is may have stiffer engine mounts which could limit vertical engine travel more so than regular 335i mounts. My only issue with this is the left 335is engine mount (same side as the power steering pulley) shares the same part number with the 335i (#2 & #2).

Shave/notch your subframe
This is a relatively rare issue which may be due to a slight miscalculation of clearances/tolerances on BMW’s part. That may explain why some may only have "skid" marks on their subframe while others end up with a damaged pulley and belt (peter_tz89@N54Tech.com & little1er@N54Tech.com). With that said, perhaps removing a couple millimeters of material from the contact point on the subframe will buy us enough clearance to remedy the issue.

Here’s a video of my 50,000 mile (09/06) E92 335i showing contact marks on the subframe. Fortunately, my belt and pulley are still in good condition (for now), but I still plan on modifying the subframe when it comes time to replace the belt.



This next video shows my power steering pulley hasn't gone out of round.


Belt is still fine.


Removing air intake snorkel for a better view of the serpentine belt.


TLDR: Check your serpentine belt.

[The Ghost]

Do you now if this will be fixed for vehicles out of warranty?

[trufus]

Can anyone explain why they recommend replacing the whole front axle carrier when there has been contact? Seems like overkill...?

I am fairly certain this is what happened to me when my belt broke a few months ago. I was in a little accident (where the belt probably rubbed up on the subframe), got all patched up, then a couple months later my belt failed. Luckily nothing else broke and I was pulling into a parking lot when it happened.

[ajm8127]

Can anyone explain why they recommend replacing the whole front axle carrier when there has been contact? Seems like overkill...?

I am fairly certain this is what happened to me when my belt broke a few months ago. I was in a little accident (where the belt probably rubbed up on the subframe), got all patched up, then a couple months later my belt failed. Luckily nothing else broke and I was pulling into a parking lot when it happened.

Probably because it is shaped differently to provide additional clearance in that area.

[euro92]

Do you now if this will be fixed for vehicles out of warranty?

I don't think so. Even people with CPO warranty were having a hard time getting BMW to cover it. Hopefully this ends up being a recall sometime in the future which probably won't happen until someone brings a class action to BMW.

[nikitino25]

A possible fix for this is to install a motor mount from the 335is on at least the pulley side. I haven't done that yet; just have heard it's a beefier mount and doesn't allow as much engine movement. Keep in mind I don't know this for a fact....

[Sticky]

Good post and guys should definitely monitor this!!!

[brusk]

Any thoughts of what's causing this? I don't mean the bump I mean the physical movement of the parts. Which direction is the engine rotating, forward? How hard of a bump are we talking and are you riding on stock suspension or stiffer springs?

[Kommodore]

I've had this happen to me on my 05/08 car, twice. I have Dinan Stage 2 suspension (Shocks, Springs, anti-Rollbars)

[euro92]

Any thoughts of what's causing this? I don't mean the bump I mean the physical movement of the parts. Which direction is the engine rotating, forward? How hard of a bump are we talking and are you riding on stock suspension or stiffer springs?

Suspension is 100% stock.
How hard of a bump depends on the condition of your motor mount. It could be anything from a severe dip/pothole to a nice long right hand turn with high lateral G's.

It comes down to the left rubber engine mount not being stiff enough for the amount of room it's given. Either give it more room or find a stiffer mount (335is has the same part number for the left mount so that's no better).

Maybe we should look into stiffer transmission mounts as a way to decrease the engine's rotation. Problem is, I don't know if it's an issue of the engine rotating back to front or right to left.

[brusk]

Without actually seeing the setup I would say start with the options we have as stiffer trans bushings, IS right side mount. From there maybe a small spacer on the left side mount and maybe even notching the subframe.

[Jeremy]

It's almost always with manual trans. I already lost one and now keep one on hand and I also made my own belt tensioner wrench.

[arthur101]

hi guys my name is arthur a newbie. did anyone knows ho to use winkfp to change dme vin number i got a used dme but no idea with winkfp. thank you

[brusk]

hi guys my name is arthur a newbie. did anyone knows ho to use winkfp to change dme vin number i got a used dme but no idea with winkfp. thank you

I'm guessing you couldn't start a new thread since your new. Sent you a PM with somebody to contact for help.

[psychosinmylobby]

hi guys my name is arthur a newbie. did anyone knows ho to use winkfp to change dme vin number i got a used dme but no idea with winkfp. thank you

Smooth lol

although thanks for being this to my attention as I have never heard of this issue before (belt issue). Does anyone know if this is a common issue or not?

[BoostDr]

Do you now if this will be fixed for vehicles out of warranty?

I had the subframe replaced for this exact issue...not before i went through 3 belts in two days -__-

Unfortunately, without a warrantee its an out of pocket expense...BMW hasn't recognized the issue like they did with the turbos...

[BoostDr]

Any thoughts of what's causing this? I don't mean the bump I mean the physical movement of the parts. Which direction is the engine rotating, forward? How hard of a bump are we talking and are you riding on stock suspension or stiffer springs?

Apparently(what I was told talking to the tech that did my replacement) as the motor mounts age the motor sags down and the lower part of the belt contacts the subframe shearing the belt

[nikitino25]

Apparently(what I was told talking to the tech that did my replacement) as the motor mounts age the motor sags down and the lower part of the belt contacts the subframe shearing the belt

How many miles did you have on the car when this happened?

[Kommodore]

Mine did it starting around 70K until I went with 335is mounts. Hasn't happened since.

[BoostDr]

How many miles did you have on the car when this happened?

I had approx 66k on the car when it decided it hated belts

[illrider]

I had this happen at about 75k miles. Replaced with IS mounts as well. Really wasn't that bad of a job. Didn't have to remove the downpipes either.

[V8Bait]

If I steal a friends 15k mile '13 335is mounts and replace them with my 75k mile '07 335i mounts will he notice?

[psychosinmylobby]

Mine did it starting around 70K until I went with 335is mounts. Hasn't happened since.

I had this happen at about 75k miles. Replaced with IS mounts as well. Really wasn't that bad of a job. Didn't have to remove the downpipes either.

I am thinking about doing IS mounts while my car is getting new DPs. Is there significant NVH increase with these IS mounts? Can you confirm that the left mount is the same in the 335i as the 335is? Do you have part numbers for these parts?

Thanks a ton!

[Kommodore]

I am thinking about doing IS mounts while my car is getting new DPs. Is there significant NVH increase with these IS mounts? Can you confirm that the left mount is the same in the 335i as the 335is? Do you have part numbers for these parts?

Thanks a ton!

no

yes

not on hand. But they are easy to find on the ECS site or realoem.com

[psychosinmylobby]

Thanks! Would you recommend that they should be replaced as a preventive maintenance at 65k miles or should be replaced once I see belt wear?

thanks again