[bill3rdshift]

Hi all,

The car is fbo, ps2's, PI, Stage 3 lpfp, etc. I was driving on the highway taking it easy.

First a yellow battery light popped up, then the infamous check engine light, then with the clutch in while slowing down the idle was bouncing. I pulled over turned off the car and it wouldn't start back up. I have battery and the starter is cranking but it won't start now.

Can anyone shed some light on what these codes indicate? There are so many. I wonder if it's the DME (mosfet blew), VANOS, wiring, or battery.

[IllSic_Design]

Battery light coming on first tells us it's probably the battery being/going dead. A bad/low battery will cause all sorts of weird codes and issues to pop up in these cars. I would first try charging the battery/changing it out if it is bad and then clearing the codes and see what pops up. Also maybe check the alternator to make sure it didn't die which in turn killed the battery.

[BSM n54iS]

Second for battery

[pysical]

I had all those same camshaft codes and it was due to two bad cam sensors. I had a engine fire and it killed them. They were not melted or heated or anything but I think they shorted out and went bad. You can test them out by following this link: https://www.pelicanparts.com/BMW/tec...or_Testing.htm

The next 4 codes were due to a bad battery junction box. The red thing that sits on top of the battery. It has non replaceable fuses on the inside and mine was bad because of the fire. The thermostat and water pump run off of the red wire that plugs into it. If you turn the key on and put a test light in the back of it you should have power.

But since you got a battery light on your dash I would check out the battery first. Most likely it is a bad battery. These cars get real touchy with bad batteries.

[Tyc0]

Depending on age of battery I would do that first, low voltage does weird things to these cars.

[stewbets]

Everyone seems to be thinking battery, but this happened while driving. At that point, the battery has already done it's job and is taking a nap. This screams alternator to me or some kind of blown fuse or junction box.

[335i54n]

those are timing faults, so either a sensor/wiring went bad or you are mechanically out timing wise

[bill3rdshift]

Looks like the crank hub slipped and skipped/jumped a timing tooth. We're going to crank it by hand and pull the valve cover to investigate. Nothing but more problems and more money.

[Tyc0]

Is this a common problem?

[IllSic_Design]

Originally Posted by Tyc0

Is this a common problem?

Slipped crank hub? Not really on N54, couple cases I've seen, has been seen a little bit more on S55 though. Even then it's usually not a worry unless pushing big torque/hp or you have a random instance of it like here, since he said he wasn't even under heavy load/taking it easy.

[Dave92N54]

Originally Posted by IllSic_Design

Slipped crank hub? Not really on N54, couple cases I've seen, has been seen a little bit more on S55 though. Even then it's usually not a worry unless pushing big torque/hp or you have a random instance of it like here, since he said he wasn't even under heavy load/taking it easy.

I've heard it gets much more common on the N54 when you're running a lighter flywheel as well, not sure what OP is running. I believe it has something to do with the DMFW ability to absorb/dampen some "shock".

[bill3rdshift]

I'm still not sure of the total damage yet, until we pull the valve cover of at least. I never heard of this happening on N54's only on S55's as well. Apparently it has happened to others.

I attached a photo and the way I understand it part #5 "timing sprocket" is what slipped on the crank hub. The crank hub did not slip or spin any more than that crank itself. The timing sprocket is not keyed to the hub, but only tighten down with the #3 bolt using 76Ft. Lbs + 360 degrees.

Here is the log of when it happened. I wasn't doing anything crazy, just rolled into the throttle in 3rd - https://datazap.me/u/bill3rdshift/ti...og=0&data=3-21

Does anyone have experience with VTT's spline locking hub with an N54? There is tons of posts on S55's. Even posts about the V2 version. https://vargasturbo.com/product/vtt-...khub-solution/

Then my next thought is if I upgrade the hub will this happen again. The car is making 616whp 606Ft Lbs.

[bill3rdshift]

I'm starting a new thread with a better title to address this. Thank you everyone!

[bill3rdshift]

Quick update on this. I never did start another thread...

I had my shop fix the problem since it required a N54 timing kit and experienced technicians. They did a great job and now I'm at 640whp with tons of low-end torque and so far no problems. Props to them for great work! PM me if you want to know the shop in the Tampa Bay FL area. Thanks to Jake from Motiv for some advice as well!

I know this more common on S55's but this was on an N54 engine with 30k miles (stock internals).

Costs:
VTT Crank Hub Spline Lock $869.74
N54 Timing Kit $320.51
Timing/Crank Labor $2,900

[Dave92N54]

Curious to see how the spline lock does for you. The issue with them is that now, if whatever happened that caused your hub to spin in the first place happens again, you're in for a new motor.

[MadDog89]

Bad or incorrect battery does all sorts of weird stuff, I'd start there.

[bill3rdshift]

Originally Posted by Dave92N54

Curious to see how the spline lock does for you. The issue with them is that now, if whatever happened that caused your hub to spin in the first place happens again, you're in for a new motor.

So far it's held up. I'll let you guys know if that changes.

Where did you hear they replace the engine if it fails? I thought they only replace the part for free. Can you send me a link if you can find it?

[bill3rdshift]

Originally Posted by MadDog89

Bad or incorrect battery does all sorts of weird stuff, I'd start there.

The battery is all good, but thank you.

[Dave92N54]

Originally Posted by bill3rdshift

So far it's held up. I'll let you guys know if that changes.

Where did you hear they replace the engine if it fails? I thought they only replace the part for free. Can you send me a link if you can find it?

What I mean is that when a crank hub slips, like in your case, it only did so partially.

When you lock the hub to the crank, if whatever caused your hub to spin occurs, it will likely damage the crank. At that point it's an engine rebuild or new engine.

[bill3rdshift]

Originally Posted by Dave92N54

What I mean is that when a crank hub slips, like in your case, it only did so partially.

When you lock the hub to the crank, if whatever caused your hub to spin occurs, it will likely damage the crank. At that point it's an engine rebuild or new engine.

Oh I understand. Yes I got lucky on this one, since it only slipped. These are interference engines so if it slipped/skipped any further it would have damaged valves, head, pistons, etc. So basically a new engine would be needed. Still a costly endeavor but hopefully it holds up. Thanks.

[Dave92N54]

Originally Posted by bill3rdshift

Oh I understand. Yes I got lucky on this one, since it only slipped. These are interference engines so if it slipped/skipped any further it would have damaged valves, head, pistons, etc. So basically a new engine would be needed. Still a costly endeavor but hopefully it holds up. Thanks.

Exactly, I haven't heard if it happening much but it's always a possibility. Im sure you'll be good for a long while. Please keep this updated though i'd love too see how it all holds up.