[twernz]

So my 135i sat in my garage for a week or two because i was doing a brake job, once i finished i brought it out for the night and drove for an hour or so then came back and all was well, following morning pulled it out of garage and washed it, everything still working, but after the wash i went to start it and it's just not cranking, but the battery's not dead… the ac turns on, headlights, brake pushes down normally but won't crank. I'll hear one singular click when i hit start but nothing else happens. I've replaced the relay fuse and nothing changed, i've also checked the engine earth strap and that's fine.

i went back and messed around with it later that night and it just randomly fired up once? this was after i put the old relay in then put the new one in again just to test it. I shut it off then started it again and it started once again, then i shut it off and waited a minute and then i go to start and nothing again…

The only thing that i've done that could have broken is spilling some brake fluid out of the reservoir from the brake job or some water from the wash. I'm thinking something along the lines of battery, distributor box, starter, or the cord that runs from the battery to the starter being faulty but I have no clue.
It's the sheer randomness of it working, then not, then working, then not that confuses me

Any help, ideas or ways to test things that may be faulty would be a great help, thanks!

[gbalthrop]

Please provide the Last-7 Characters of the VIN of the car in question, and we can suggest some tests. Please also indicate if you have (1) Scan Tool (Make/Model), (2) Diagnostic Software (INPA/ISTA), (3) Multimeter?
George

[whyzee125]

That is almost certainly a failing starter/solenoid. I've never had a starter failure on an e9x, but every other car I've experienced it on, this is how it started.

[mainbearing]

The starter is buried in there, but if you can verify proper voltage on the attempt to start then it's probably the starter. Checking ECU codes can tell you more.

That was why I replaced the starter preventatively with an aftermarket TYC. This one is a stronger 1.2kW starter vs many older 1.1kW units out there. Fast and strong cranks. Previously with the factory junk, I thought my battery was weak, but it was just the Bosch starter.

My starter notes:
https://www.e90post.com/forums/showp...3&postcount=18

and the pivoting ratchet that helped with the rear facing bolt:
https://www.e90post.com/forums/showp...4&postcount=94

[twernz]

Originally Posted by gbalthrop

Please provide the Last-7 Characters of the VIN of the car in question, and we can suggest some tests. Please also indicate if you have (1) Scan Tool (Make/Model), (2) Diagnostic Software (INPA/ISTA), (3) Multimeter?
George

Originally Posted by gbalthrop

Please provide the Last-7 Characters of the VIN of the car in question, and we can suggest some tests. Please also indicate if you have (1) Scan Tool (Make/Model), (2) Diagnostic Software (INPA/ISTA), (3) Multimeter?
George

It's a 2009 135i, last 7 digits are vk95450, it's throwing the codes A0C1, A0B6, A0B5, A0B4. Also checked the battery in the engine bay with a multimeter, read about 12.1…

[eljay]

Did you notice slower cranking in recent months/weeks?
If yes, this was the starter's final straw.

[Tambohamilton]

Originally Posted by twernz

It's a 2009 135i, last 7 digits are vk95450, it's throwing the codes A0C1, A0B6, A0B5, A0B4. Also checked the battery in the engine bay with a multimeter, read about 12.1…

My money is on the starter being dead, but 12.1v is also not great. I'd recommend you hook up a decent charger, as a weak battery will cause all kinds of misbehaving.

[Tambohamilton]

Here's a gbalthrop post from another forum regarding A0C1 and some troubleshooting:
https://www.bimmerfest.com/threads/2.../post-13443993

[twernz]

Originally Posted by eljay

Did you notice slower cranking in recent months/weeks?
If yes, this was the starter's final straw.

Originally Posted by Tambohamilton

Here's a gbalthrop post from another forum regarding A0C1 and some troubleshooting:
https://www.bimmerfest.com/threads/2.../post-13443993

it's been completely normal until it just didn't start

[ozi]

You might want to check the ground cable which is below the car if its loose or just about to break

[twernz]

Originally Posted by mainbearing

The starter is buried in there, but if you can verify proper voltage on the attempt to start then it's probably the starter. Checking ECU codes can tell you more.

That was why I replaced the starter preventatively with an aftermarket TYC. This one is a stronger 1.2kW starter vs many older 1.1kW units out there. Fast and strong cranks. Previously with the factory junk, I thought my battery was weak, but it was just the Bosch starter.

My starter notes:
https://www.e90post.com/forums/showp...8;postcount=18

and the pivoting ratchet that helped with the rear facing bolt:
https://www.e90post.com/forums/showp...8;postcount=94

replaced starter and it was that, thanks for the help!

[rt7085]

Yeah I experienced the same on my e91 328xi. It begins with slower starts. Its subtle but I noticed it. This went on for a good couple of months. And then all of a sudden a couple of really bad starts where it really hesitates or even fails and you have to try again. And then one day: Nothing. There are plenty of warnings that for some strange reason I ignored. I am normally the 'preventative maintenance' type of person. The new starter is much stronger. While you are under the intake, make sure you replace the crank shaft flywheel sensor. These are known to go at age and that is another no-start reason.