[victor247]

Hi everyone.
I have a 2008 335i Single Turbo e93.

Before I jump in, I'd like to mention I used the search feature and haven't found anyone with a similar issue to mine and Iv'e done a bit of diagnosing already. I appreciate all the help I can get.

I was driving the car one evening, everything was working per usual. I parked it in my driveway and shut it off. A few hours later I came back and tried to start it. Everything powers on but it wont start. It doesnt even click.

When I put in the key and press the start button, I need to press it a 2nd time and all the lights turn on. I press the clutch and the brake, and the key slot just ejects the key and turns the ignition off. No codes(scanned with MHD).

I have a fairly new battery.
I bench tested the relays. One from the glove box area and one from under the hood near the computer module.
I tested the fuel pump, it works, but the wires to the pump don't have any power.
I checked all the fuses and they are all fine.
I checked the ground wire from the engine to the frame, and that seems solid.

What do you guys think it can be? The CAS module?
Would a bad starter eject the key?

Possibly brake or clutch pedal switches?
My bake is really hard to press right now. My driveway is fairly steep.

[RockCrusher]

My first impression is the behavior is a sign of a bad (or at least low) battery.

The battery is new. Ok. But that doesn't mean the new battery can't be bad. (I had a new battery go bad after just 5 months.)

Or the battery is not bad just low. This can arise from a bad alternator.

Of course I've had experience in this area too. Was in one of my cars -- a 996 Turbo -- and driving around and for about 30 minutes all was well. Happened to check the voltage gauge and it was down under 13V where before it always was above 13V close to 14V.

I knew what was wrong. Pointed car towards dealer -- about 10 miles away -- and made it ok. Tech confirmed alternator bad and I had a new one (factory rebuilt) installed.

I'll mention that last thing touched is first thing suspect. Of course this includes the new battery which I've already touched upon.

But be sure you check battery cable connections. Not unknown for a cable connector be left a bit loose.

[victor247]

Thank you!
I'll be checking that next.
I was wondering if someone had a similar issue to mine, but as you stated, I should be checking the obvious first, which is the alternator and battery. I'll get it tested and update the post shortly.

Originally Posted by RockCrusher

My first impression is the behavior is a sign of a bad (or at least low) battery.

The battery is new. Ok. But that doesn't mean the new battery can't be bad. (I had a new battery go bad after just 5 months.)

Or the battery is not bad just low. This can arise from a bad alternator.

Of course I've had experience in this area too. Was in one of my cars -- a 996 Turbo -- and driving around and for about 30 minutes all was well. Happened to check the voltage gauge and it was down under 13V where before it always was above 13V close to 14V.

I knew what was wrong. Pointed car towards dealer -- about 10 miles away -- and made it ok. Tech confirmed alternator bad and I had a new one (factory rebuilt) installed.

I'll mention that last thing touched is first thing suspect. Of course this includes the new battery which I've already touched upon.

But be sure you check battery cable connections. Not unknown for a cable connector be left a bit loose.

[landragon]

Had a similar issue this week although I could hear clicks. After getting towed, they said the ground cable from the engine to the frame had rusted and broken away.

Diagnosis: 150$
Replacement: 150$
Part: 49$

Almost 350$ to unscrew and reconnect a new cable.