[golfbrah]

Cleaned out the crank pulley, engine got close to starting but died. I'm hoping to start the engine just to hear what sounds it makes for a better diagnosis. Battery needs to charge overnight so the repair continues tomorrow...

[shawn.yoder01]

my 07 335i keep shredding belts, i still can't find the culprit. luckily none of the pieces have damaged my seal. i'm sure some have gotten into the oil by now, but that is project and a half to get my oil pan off.

[arkie6]

Originally Posted by shawn.yoder01

my 07 335i keep shredding belts, i still can't find the culprit. luckily none of the pieces have damaged my seal. i'm sure some have gotten into the oil by now, but that is project and a half to get my oil pan off.

Have you checked your power steering pump pulley for damage? Have you checked the front cross member below the pulley for evidence of contact with the pulley? If the hydraulic motor mounts collapse, this can allow the power steering pump pulley to contact the frame cross member causing the back edge of the pulley to be damaged which in turn can damage the accessory drive belt.

[Bigmadman]

Originally Posted by golfbrah

Cleaned out the crank pulley, engine got close to starting but died. I'm hoping to start the engine just to hear what sounds it makes for a better diagnosis. Battery needs to charge overnight so the repair continues tomorrow...

Hey brother I have an 07 335i and I have the same problem where the belt got past the crank seal and messed up my timing... what steps are you taking to get the pieces of belt out and your timing back in line? I been stuck on this for a very long time and any help would be really really appreciated!!

[castanoval]

Hi everyone,

Quick question:
From those who experienced the issue, how many miles did you drove the car for after the belt broke?


I am towing my car tomorrow to the shop. I wanted to ask you all, based on your experience, for me to get a sense of my expectation for tomorrow. In my case, I drove it 4 miles at low RPM after the belt broke.

Thank you in advance.

[landshark328]

Castanoval: I drove my car a couple miles before I realized it was the belt and not just a power steering issue. My seal was compressed into the engine.

Question: My indy claims to have done the post-belt shred engine inspection 25+ times and recommends dropping the oil pan but not the valve cover. The tech recommended running a boroscope up there only. Should I push back and ask him to remove the valve cover as well?

[JWT4700]

Originally Posted by landshark328

Castanoval: I drove my car a couple miles before I realized it was the belt and not just a power steering issue. My seal was compressed into the engine.

Question: My indy claims to have done the post-belt shred engine inspection 25+ times and recommends dropping the oil pan but not the valve cover. The tech recommended running a boroscope up there only. Should I push back and ask him to remove the valve cover as well?

I shredded my belt and was unaware that they actually get into the engine, my motor actually lasted a year before blowing up, around 8 months I started having a lot of odd issues, month 11 i pulled the valve cover to replace a sensor.... I found pieces of serp belt. Mainly around where the cam chain runs. I'll have to see if I still have a picture. There was a lot of belt remnants under my valve cover, so I would check! To be fair I had ample time over the course of a year for it to make it that far, but I'd still check.

[golfbrah]

All good after dropping the oil pan

[golfbrah]

Originally Posted by Bigmadman

Hey brother I have an 07 335i and I have the same problem where the belt got past the crank seal and messed up my timing... what steps are you taking to get the pieces of belt out and your timing back in line? I been stuck on this for a very long time and any help would be really really appreciated!!

There's a chance that you don't have a problem with timing. Low oil pressure, especially on cold start, can throw a timing code because VANOS can't fully activate. Fix oil pressure by dropping oil pan and cleaning the tube = fix timing.

[JWT4700]

I would suggest pulling the valve cover too. I had small pieces of belt laying around on the edges of the cam chain valley... I ran mine a lot longer tho, so maybe mine just had more time to circulate thru the system.

[Mochoa335]

Thank you so much been looking for a DIY on this

[Championhustle]

Are you able to remove the pieces of belt wrapped around the crank directly behind the front seal from the oil pan? Thanks

[rwphillips7]

Mr Malvo,

Thanks for a detailed DIY. After following your example, I did find two small belt piece's attached to the seal and from what I could see are a few divet's around the seal but couldn't determine if it is compromised. I don't have a lot of room to get a straight on look of the seal. Do you believe removal of the oil pan is warranted? Thanks

[TDF9]

Just found pieces of belt wrapped around my cooling fan, and now on inspection, see the inside (nearer the engine) of my belt shows signs of being frayed (the belt itself, less than a year old, remains in tact and in place). I plan to pull off the crankshaft pulley (is that the harmonic balancer, too?) and inspect for more debris and seal damage, but am curious 1) how and why this occurred (slight, partial, inside belt fraying - N52, in case relevant), and 2) if anyone has experience I might learn from with a similar "partial failure" and/or debris landing in cooling fan?

I addressed the OFHG issues two years ago, and replaced the motor mounts last year when I did the oil pan gasket. Replaced the tensioner and pulley when I did the belt year ago. Car is a 2006 325i with 230k miles. I just did a track event couple weeks ago, so the car for a workout / sustained high revs.

I appreciate any ideas or insights

[mr_malvo]

The amount of belt in your hand seems concerning. Certainly remove the front pulley and check your seal. I can't tell from the pictures if the amount of belt pieces corresponds to the amount of damage your belt has, but could be.

If you haven't had the car for too long maybe the belt pieces are remnants from a previous failure that was never properly cleaned up. But reading your repair history seems like you've had it for several years.

As for your belt failing maybe one of the other pulleys is damaged and cutting your belt. You would need to inspect them. Specially the power steering one.

Originally Posted by TDF9

Just found pieces of belt wrapped around my cooling fan, and now on inspection, see the inside (nearer the engine) of my belt shows signs of being frayed (the belt itself, less than a year old, remains in tact and in place). I plan to pull off the crankshaft pulley (is that the harmonic balancer, too?) and inspect for more debris and seal damage, but am curious 1) how and why this occurred (slight, partial, inside belt fraying - N52, in case relevant), and 2) if anyone has experience I might learn from with a similar "partial failure" and/or debris landing in cooling fan?

I addressed the OFHG issues two years ago, and replaced the motor mounts last year when I did the oil pan gasket. Replaced the tensioner and pulley when I did the belt year ago. Car is a 2006 325i with 230k miles. I just did a track event couple weeks ago, so the car for a workout / sustained high revs.

I appreciate any ideas or insights

[TDF9]

Thanks so much for your response, mr_malvo.

Just pulled the main pulley and really can't tell what I'm looking at. Will attach some pix of main seal, and appreciate anyone's take on if it's been compromised (or perhaps is just a little leaky).

At least there was no debris around it, as there was on the fan.

I also can't find any obvious explanation for why the belt deteriorated, and from the inside / engine side. Will attach pix of power steering and AC pulleys and main pulley, although I realize it may be impossible to tell anything from them.

Should I be replacing the main pulley at 230k miles anyway?

Grateful for all replies!

[mr_malvo]

Good news, your front seal looks intact.

As for the pulleys, the belt contact surfaces seem to be ok. You would need to run your hand around them to make sure there are no nicks or sharp edges that could have damaged your belt. If you feel something with your fingers then try to do a closer inspection and replace pulleys as needed.

If all seems good with the pulleys then I'm not sure what would have caused your belt to fail. Seems like you're already corrected the Oil Filter Housing Gasket so no oil dripping on it. Maybe inherent defect with the belt, or some other unknown factor.

Originally Posted by TDF9

Thanks so much for your response, mr_malvo.

Just pulled the main pulley and really can't tell what I'm looking at. Will attach some pix of main seal, and appreciate anyone's take on if it's been compromised (or perhaps is just a little leaky).

At least there was no debris around it, as there was on the fan.

I also can't find any obvious explanation for why the belt deteriorated, and from the inside / engine side. Will attach pix of power steering and AC pulleys and main pulley, although I realize it may be impossible to tell anything from them.

Should I be replacing the main pulley at 230k miles anyway?

Grateful for all replies!

[TDF9]

Thank you so much for the reply!

Pulley inspection revealed nothing amiss, so am just going to have to monitor the new one and see how it goes.

[DougNBodie]

Does anyone know if this belt eating issue on the N engines can happen on the M57 engine as well? I saw this and about shyt myself in fear, so I set out to buy a crank shaft sealer guard but can't find one anywhere for the M57 Diesel engine. Thanks

[Learningthehardway91]

I'm pretty sure Im on number 7.a

Are there any guides out there on what to do next? I'm strapped for cash and in a tough place, and I would like to do it on my own, I've replaced and retired a timing chain for a Nissan Altima so I have a good idea of what's required, i just need the steps. Please I'm running out of time!!

[mr_malvo]

Dang. Sorry to hear that. Sounds like removal of the valve cover is your next move. That way you can at least inspect part of the timing chain. Removing the oil pan also gives visual access to the timing chain.

Originally Posted by Learningthehardway91

I'm pretty sure Im on number 7.a

Are there any guides out there on what to do next? I'm strapped for cash and in a tough place, and I would like to do it on my own, I've replaced and retired a timing chain for a Nissan Altima so I have a good idea of what's required, i just need the steps. Please I'm running out of time!!

[335.Trickss]

My serpentine belt snapped on me while driving , I wasn’t aware it snapped but I had a battery light on. I got home and parked the car and thought it was the battery. Opened the hood to see a shredded belt . Long story short I replaced belt and pullies , I’m working on changing the gaskets. However I need to take it to a shop for one of the fixes(oil pan gasket and check if belt pieces are in engine) and I heard the dealer told me it might have a chance of oil depreciation if the belt made it past the seal and into the oil. I’m just wondering if it’s safe to drive or do the shop I have to go which is about 20-25 miles out from my house or should I look for towing. I drove it to the dealer first without knowing any risk of serpentine belt being in the oil sump . I just want to know if I’m about to drive it mad 25 miles to the next shop without oil depreciation if belt pieces made it past the seal. ?? Any one plz help me out ? I have to go pick it up from bmw shop later and idk if I should drive it to the next shop where ima get it fixed . I think I can make it there witho it anything bad happening but idk I’m not a bmw expert , I just got it 2 months ago.