[DaanBMW]

So this morning my car simply did not start anymore. Was parked in garage. FWIW - The starting has gotten progressively slower lately, meaning that it was turning very lazy (esp. after a night in the garage) but eventually it did start.

With clutch pedal pressed, all the dash lights are on no problem, but all I hear is a humming/whirring noise coming from the trunk - and which dies down after several seconds - and nothing else. I did not hear a clicking sound either, but I was not really paying v much attention to it.

I don't think it's the battery, as my previous one used to shut off after leaving the ignition w/o the engine on, and displayed a battery image in the dash. Battery is ~4yrs old. Have not checked voltage yet though, I will later on.

Codes are plenty as I also have the ESS disconnected (due to a bad sensor) but this doesn't even throw codes as the car just goes in fail-safe driving mode using the throttle instead of the VVT (I know this as I've tried it before as parts of other troubleshooting).

New code seems to be only A0B4 - which sure enough is "Fault engine start starter". So is this for sure the starter ? I read all sorts of other stuff like gourd wires etc.

[hassmaschine]

sounds like your starter is toast to me.

[nsjames]

yep.

they fail suddenly and completely.

[DaanBMW]

Just checked battery - 12.5V

Checked engine ground cable - not corroded or loose or bolts loose. Even tugged on it, it's good, even more flexible than I expected.

So starter for sure ? I assume this means I should swap the solenoid as well right ? Pretty much everything here: http://www.realoem.com/bmw/enUS/show...diagId=12_1161

[nsjames]

new starter will come with attached solenoid as a unit.
You'll want a flex head 3/8 drive ratchet for the bolt that's facing the firewall. Makes it much easier and allows you to get the socket on it properly.

pull the manifold, replace the starter, done. My brother and I did it in a hotel parking lot in the rain in about 2 hours, neither of us had ever puled the manifold of an N52 car.
Pelican has an excellent guide in the tech library.

[Volasko]

Simple test is if you boost the battery and the starter still doesn't work it must be the starter. When mine failed it was very similar to your symptoms, starts were slower and slower (like a dying batter) then suddenly failed.

[DaanBMW]

Originally Posted by nsjames

new starter will come with attached solenoid as a unit

yes, I confirmed with both ECS and FCP atht the new units come with solenoids. A bit stupid both only show the motor in the listing.

Originally Posted by Volasko

Simple test is if you boost the battery and the starter still doesn't work it must be the starter. When mine failed it was very similar to your symptoms, starts were slower and slower (like a dying batter) then suddenly failed.

The battery was 12.5V with no start, so I don't think I need a boost to conclude it's not the battery - or ?


.....

BUT today while trying to have it towed I actually push started it in reverse. Was careful not to press the stop button all the way to my repair guy :-). Then I got there, I stopped it. Then just for kicks I tried to start it. STARTED RIGHT UP !!! Tried it 3 or 4 times, started each time no problem and no hesitation.

WTH does this mean ??!!? Anyone hav any ideas ?

[nsjames]

possibly a connection issue.
possible that the starter simply moved passed the dead spot in it's rotation with some vibration. Same reason that whacking a failing starter with a hammer often makes it work a few more times.

[DaanBMW]

Well, I guess all is well when it ends well. It was indeed the starter, despite it sporadically working. When we got it off, you could pull the inner gear shaft out by hand, which is near impossible on a new one. Not sure if this is the cause, but that we only difference we could find, otherwise it's no different to the naked eye.