BMW 1 Series Won't Start? Troubleshooting Guide.

Hello, I'm having a problem where my 1Z engine won't start. The starter motor has been struggling to turn the engine over for the past few days/weeks. However, once it manages to rotate the engine about one revolution, the engine starts immediately. So, generally speaking, the engine starts very well.

Since I was thinking about the battery, I just replaced it as a precaution. It also seemed to start up a little easier with the new battery at first.

'However, as of today, the starter motor can't even manage that one rotation. It just makes a loud 'clunk' sound and then stops.' What's a bit strange about it is that there's NEITHER a strong jolt felt through the car NOR do the dashboard lights go out when I try to start the vehicle.

Does anyone have any idea what this might be about? I'm afraid the engine has seized up again.

Thank you very much in advance.

Oliver.

HugoHiasl wrote:

As of today, the starter motor can't even manage that one revolution. It only makes a loud "TOCK" sound once, and then it stops.

What's a bit strange about this is that there's NEITHER a strong jolt felt through the car, NOR do the displays in the car go dark when I try to start the vehicle.}
Sure, here is the translation of the text from German to English:

"Hi,"

To me, this smells strongly like a worn-out starter motor (e.g., worn brushes) or a resistance issue within its power circuit, including the main ground cable (corroded terminal, broken wire, etc.).

The latter can often be located by listening for a sizzling sound (or the attempt to do so) caused by a hot spot -> Caution: There is a risk of burns on exposed metal parts.

Thank you very much!

I ordered a new starter motor for €113 including shipping, and it was installed today.

Everything is working perfectly again.

The diagnosis was spot on...


Best regards.
Oliver.