Belt ripped apart the engine harness...total loss??

[gingy_135i]

Hello everyone, I’ll try to keep this straight forward and sweet. I’ve had my 2012 135i (50k miles currently) for about 9months and I LOVE MY CAR! Unfortunately the belt ripped off no joke 5 minutes after picking her up from the detail shop to get her fully restored on the outside and she was beautiful…for those 5 minutes 😂 As I came to a stop light the revs jumped up and just new something was off…I heard something pop followed up with some slapping on the front end seconds later, then followed up with a dash board full of lights coming on. I was able to pull into a circle k and turn her off in a matter of minutes! Unfortunately the damage was already done and in the worst kind of way. The engine belt popped off and got eaten into the front crank seal and while this maybe is the worst case scenario it gets worst….when the belt broke it ripped apart the engine harness and took it for a spin. I have the car at my mechanic shop and here’s the news. One of my pulleys have shattered along with destroying most of the others(as expected) ripped apart the engine harness. I have material in my oil so have to take off valve cover and drop subframe to clean everything out and hope that nothing has worn down or damaged itself. THEN we can start to repair the engine harness which is just a night mare. The Indy BMW shops here in AZ all have a liability clause so they don’t allow you to bring your own parts even if they are OEM ( I get all my stuff from FCPEURO and ECS) and rather they buy directly from the dealer ship 😤 this has made getting the repairs I can’t do ( I live in a apartment complex with no garage) insanely expensive. They are getting a whole host of codes they can take care of once it’s finished doing those repairs and they say the engine is completely salvageable BUT they are seeing a code they’ve never seen before (don’t have it on hand but will update later) regarding a power distribution code I believe it was. They think when the engine harness was ripped off it caused things further back to get unplugged or possible loose a grounding cable (best case scenario) or it further ripped apart some things down the line. So in order to find out I would need to repair the car and all the damage to get her turned on and running before they can truly dig deeper to find out that issue…the quote for this job is $7200😯 this is something I’m willing to pay because I love my car and simply don’t have another one to drive and wouldn’t make sense to buy another car and go further into debt when it would be less debt to repair this car. This is my logic, Please help me understand is this even worth it or is it a lost cause ?!?!

[ShocknAwe]

How about getting a salvaged harness?

What an awful thing to happen.

[gingy_135i]

I would love to but the Indy shops only deals with getting parts from the dealership(at least the shops I have called in my area) here in AZ so I couldn’t get a used harness. I don’t have the skill to repair a harness granted I wouldn’t mind learning if they’re is a post or guide they can be as clear cut as possible in this situation but if I fail to fix it then the shops in the area wouldn’t want to touch it or if they do then replace the work I tried to do myself and the cost would continue to go up.

[ShocknAwe]

Can they not source the harness from a dismantler? Have you asked?

[gingy_135i]

Great idea, I’ll have to ask come Monday morning when they open up! I got the news of all the damage and what’s happened Friday afternoon so took a little bit to process and trying to figure something out. Trying to collect what is possible and doable come Monday when shop opens up !

[ShocknAwe]

Good luck let us know how it goes!

Should be possible to take a harness off a wrecked car and use it. Then as long as nothing internal was damaged when the belt went through the crank seal you'll be good to go. I'd use this opportunity to replace the bearings as well.

My worst recurring nightmare is electrical gremlins. It's the kind of thing that keeps you up at night. Would be better to start with a known good harness installed while the engine is out. Wiring repairs to the existing harness of unknown quality and then ENDLESS problems later is avoidable.

[gingy_135i]

Update Pt.2

After talking to the shop and getting better clarification on everything that needs to be done things aren’t looking that grim. They assured me the engine will be just fine with no issues once all repairs are done! They informed me when the belt gets forced into the front crankshaft that the timing belt forces the belt downwards into the oil pan where the pick up lines will suck up the bits. There is no need (for now) to go through the top and remove the valve cover and doing anything up top.

Game Plan

This job is very labor intensive…
1) Dropping oil pan, which means subframe has to come out. At least the oil pan gasket will be replaced 🤌🏻
2) clean out all belt bits from the pan, oil feed lines and screen inside of the lines.
3) replacing engine mounts as they are have easy access with subframe out and needing to be done as we put it back together(PM)
4) replacing Crankshaft seal, switching to the front bottom of the engine now. The shop is cool with me buying the Tuner Motorsport crank seal guard and crank bolt capture- https://www.ecstuning.com/b-turner-m...9453la01-02~a/
https://www.ecstuning.com/b-vargas-t...t-s55-cbc~vtt/
5) replacing belt tensioner w/pulley, deflection pulleys and belt.
6) OFHG & Oil cooler Gasket w/engine oil thermostat housing. Cracking open all these lines to follow up with cleaning everything out and making sure to get all belt bits cleaned and added preventative maintenance(PM).
7) Lastly Engine wiring harness- Sensoric Module 2! The part that gave me the most anxiety when they told me the news lol the plan before this was to splice the wires where needed to repair the harness but after ShocknAwe gave great insight about future electrical gremlins that can pop up I opted for replacing the harness entirely especially seeing I’m buying it anyways. Don’t want to stay awake at night thinking something else may go wrong.

Still needs work

They have assured me all but two codes will be cleared and resolved once these repairs are done. They are still getting two codes(essentially the same one) which they haven’t seen before which they can’t fully diagnose until the car is running and has oil pressure ect. The code(s) is Terminal 87_1: No Voltage, Terminal 87_2: No Voltage. This could be as simple as a blown fuse and or loose ground(or both) and just like that things are good to go! OORRR the engine harness that got ripped and pulled damage things down the line (even more doomsday news for my car and wallet) which we won’t know till things are back up and running. Will keep you guys updated! Won’t have her up and running for at least another 2ish weeks. Approved the repairs yesterday morning and waiting for parts ect before work will commence. Shop will try to take pics along the way for me so I can show the damages and how things are progressing.

[ShocknAwe]

Good luck! Hope it's a quick thing.

[deyrag]

any updates?

[PerformanceEngSolutions]

gingy_135i How’d this end up working out? Also a good idea to change out the coolant “Mickey mouse” flange with a metal one since that’s prone to cracking after many thousands of miles of heat cycles. Sits right above the belt so any coolant leakage would drip down on it

[uglypedro]

What a nightmare!

I've been thinking about getting a "collar" for my crank or I also saw a Kevlar reinforced belt. Either seems like money well spent.

[Malo_Industries]

Man, that’s a rough situation — sorry you had to deal with this.

From what you described and the photos, the sequence you’re being told does make sense: once the belt comes apart and gets pulled in, it can cause a cascade of secondary damage very quickly. Belt debris can get wrapped and flung around once it starts shredding, which is where a lot of the collateral damage comes from.

The good news (if there is any) is that if the shop has already inspected timing, compression, and oil pressure and everything checks out, then this often is a contained repair rather than a full engine-loss situation. The belt event looks dramatic, but it doesn’t automatically mean internal damage if it was shut down quickly.

I agree with the approach of:

Dropping and cleaning the oil pan

Replacing the belt, pulleys, and tensioner

Making sure no debris is left in the pickup

Addressing any damaged wiring properly rather than patching it

As far as whether it’s “worth it” — that’s really a personal call, but at ~50k miles, the car itself is still relatively low-mileage. If the engine checks out internally, repairing it properly now is usually the cheaper option compared to starting over with another unknown used car.

Hopefully the shop kept you updated.

Let us know how it went!

[deyrag]

if it has not been completed yet it would be worth at least checking the rod bearings while the pan is off