'08 M3 takes 40+ tries to cold start, starts fine after that

[youngstatic]

My E92 M3 is having starting issues ONLY on cold starts. Getting codes 278D and 2B59 when I try to cold start in the morning. I hear a humming noise but no crank until like 20-30 tries when it decides to start. Once it cranks it starts no issue and the codes go away. Today, i couldn't get it to start at all but as soon as I jumpstarted it, it started perfectly fine and was good for the rest of the day. Replaced the battery last year, could it be the alternator? or should i check the battery first?

[Bubbles]

Originally Posted by youngstatic

My E92 M3 is having starting issues ONLY on cold starts. Getting codes 278D and 2B59 when I try to cold start in the morning. I hear a humming noise but no crank until like 20-30 tries when it decides to start. Once it cranks it starts no issue and the codes go away. Today, i couldn't get it to start at all but as soon as I jumpstarted it, it started perfectly fine and was good for the rest of the day. Replaced the battery last year, could it be the alternator? or should i check the battery first?

Check ground wires, if ok, then it’s probably your starter. $240-$300 for a reman starter and $5-7 for bandaids.

[Redd]

If it's alt your battery will run flat. Possible ground cable or cable from starter to alt. But if it's a cable problem it usually happens when car is hot due to higher resistance when hot. So my guess is also starter is due to be replaced.

[tdott]

Battery cable recall done?

[youngstatic]

Originally Posted by tdott

Battery cable recall done?

don't think so.
the only recall i remember they did was replacing the airbag in the steering wheel.

[tdott]

Code 278D is:
Description: BSD; Alternator: Missing

While this doesn't mean it isn't charging, it can be a sign that there are issues and you should have it checked. I've seen cars run for months with this code, but it's best to change it when it starts giving you trouble.

[youngstatic]

Originally Posted by tdott

Code 278D is:
Description: BSD; Alternator: Missing

While this doesn't mean it isn't charging, it can be a sign that there are issues and you should have it checked. I've seen cars run for months with this code, but it's best to change it when it starts giving you trouble.

yea I ordered an alternator based on the code but now im getting a lot of suggestions that it might be the starter motor because the car starts and runs completely fine after the cold start.

[tdott]

Originally Posted by youngstatic

yea I ordered an alternator based on the code but now im getting a lot of suggestions that it might be the starter motor because the car starts and runs completely fine after the cold start.

I think they are two separate problems.