[Tallytuner]

Hey all,
yesterday, a friend of mine who's a master tech and I replaced my valve cover gasket for my e92 335i, 07. We put everything back, and the car started up.
I drove it to an evening class, left It for 30m, and it started again, no issue.
I went out to dinner with the friend, stayed for about an hour and a half, and the car wouldn't start. Clutch down, key in, nothing. All accessories came on, lights seem alright, not dim. We push started it, and no problem. But it won't start on its own.

I checked the grounds and the negative terminal this morning, and everything was tight.
any ideas?

[ctuna]

How's your battery if you didn't disconnect it while working on the
car there is a good chance it stayed awake and depleted your battery.
Put a slow overnight charge on it .

[Tallytuner]

Originally Posted by ctuna

How's your battery if you didn't disconnect it while working on the
car there is a good chance it stayed awake and depleted your battery.
Put a slow overnight charge on it .

battery was disconnected, but I'll try to jump it since I have a kit at home and see how that goes

[Tallytuner]

Update: I tried jump starting the car. It read about 12.7 amp on my jump kit and still nothing, not even an attempt to turn over.

I do hear some sort of noise when I push the key, a low hum, like an airplane flap slowly moving or being tested (sorry for lack of examples).
Everything else in the car seems good; I don't think it would be fuel pump or anything on the motor itself; we successfully roll started it twice yesterday, and everything worked like a charm. I'm just not sure what could have come lose or gone bad in that short period of time.

[SpartaEvolution]

Did the car at least try to start? edit: didn't see your latest post.

The hum might be your fuel pump priming or maybe an HVAC vent moving. If the starter isn't getting power it's probably worth it to check fuses and relays for the starter, clutch / neutral safety switches (I think you only have the former but I'm not sure). How long were the drives to class and to the dinner spot? If they were short enough it could have drained the battery enough to prevent a start, but in that case it would at least try to start. The battery terminals could also be loose, but then the lights would probably be acting up too.

[RomKaN54]

Originally Posted by Tallytuner

Update: I tried jump starting the car. It read about 12.7 amp on my jump kit and still nothing, not even an attempt to turn over.

I do hear some sort of noise when I push the key, a low hum, like an airplane flap slowly moving or being tested (sorry for lack of examples).
Everything else in the car seems good; I don't think it would be fuel pump or anything on the motor itself; we successfully roll started it twice yesterday, and everything worked like a charm. I'm just not sure what could have come lose or gone bad in that short period of time.

if you roll started the car and it worked then clearly its a starter issue

[Tallytuner]

Originally Posted by SpartaEvolution

Did the car at least try to start? edit: didn't see your latest post.

The hum might be your fuel pump priming or maybe an HVAC vent moving. If the starter isn't getting power it's probably worth it to check fuses and relays for the starter, clutch / neutral safety switches (I think you only have the former but I'm not sure). How long were the drives to class and to the dinner spot? If they were short enough it could have drained the battery enough to prevent a start, but in that case it would at least try to start. The battery terminals could also be loose, but then the lights would probably be acting up too.

You mentioned checking the relays; are those part of the wiring cluster mess that's near the ECU wiring?

What about the safety switches? Where do I find those, and what should I look for?
The drives were each 20m maybe, tops, but the battery was still fine this morning and afternoon when I tried starting again. I'll definitely try to check this relays and switches though; another friend is thinking that something wasn't connected back fully and came loose on a drive.

[SpartaEvolution]

Having done some more research on this specific problem, the forums suggest that a relay or fuse probably isn't the cause, especially since it would have to have been a coincidence to happen right after you did the valve cover gasket.

Have a read through this thread and try some of the things suggested there. One solution that sounds promising and related to the valve gasket job is if you removed an engine ground wire, you may not have snugged it down tight enough, allowing it to wiggle loose when driving as your friend suggested.

[TemjinX2]

if the flapping sound is coming from the glove box it means your battery is low. just take it to autozone and they'll charge your battery for free.

[Supra2k6]

Try to push start if not check if 12v i reaching the starter solenoid not the starter itself.

The starter body has a constant 12v from the battery the solenoid small box nxt to it should receive 12v when u turn the key only.

[Tallytuner]

Originally Posted by Supra2k6

Try to push start if not check if 12v i reaching the starter solenoid not the starter itself.

The starter body has a constant 12v from the battery the solenoid small box nxt to it should receive 12v when u turn the key only.

sorry, what? It did successfully push start before, but I'm not sure what else you mean

[smallseafishie]

Could be loose power cable to stater or to power block where battery is (check fuses back there too), loose ground to engine (driver side near engine mount), bad starter, bad starter signal (from CAS module), low battery.

[Tallytuner]

ended up being the starter by coincidence, thanks all!

[steel609]

Originally Posted by Tallytuner

ended up being the starter by coincidence, thanks all!

Are you/did you change this yourself?