Possible Alternator Issue?

[dfwashere]

Hey guys and gals, recently, in December (12/24) i changed the original (no bs lol) battery in my 08 e90 m3 after getting the low battery light on. after the swap, its been great since.

This morning after getting to work, i got the low battery light on again. i still need to check voltage etc but was wondering if anyone else has ran into this problem too.

Possibly bad battery from BMW? Alternator? the new replacement battery is an OEM BMW battery as well.

Thanks for the help!

[m3peat]

My alternator failed after 10 yrs/124k miles and took the battery with it. Had to replace both and it’s been fine since for 2.5 yrs.
so yes, it could be your alternator that is failing. Did you check for codes?

[dfwashere]

Originally Posted by m3peat

My alternator failed after 10 yrs/124k miles and took the battery with it. Had to replace both and it’s been fine since for 2.5 yrs.
so yes, it could be your alternator that is failing. Did you check for codes?

Going to when i get home today as well as check voltage. no cel's either but yea im going to look into it more.

[dfwashere]

Pulled codes and am finding:

278D BSD: Alternator Missing
2B59: Coolant Temp monitoring
2740 + 2741: O2 Sensor Bank 1 and Bank 2 before Cat
2B13: Speed Recording
2792 DME: Power Management
2AFE DME: Voltage at terminal 87

[dfwashere]

After completing more test, the alternator was indeed going out. Was no problem charging at idle but as soon as I gave it some gas it was draining quickly.

[askme]

I lost my battery and then Alternator. Once I watched enough video to understand the slip bolts and how to don them, replacing the alternator as like a 45 min job for an idiot with the wrong tools. Do it to get peace of mind.

[dfwashere]

Originally Posted by askme

I lost my battery and then Alternator. Once I watched enough video to understand the slip bolts and how to don them, replacing the alternator as like a 45 min job for an idiot with the wrong tools. Do it to get peace of mind.

Thats what i wanna hear lol. it def doesnt seem like a job thats too hard. thankfully access isnt too terrible like on other vehicles.

[Denny347]

Originally Posted by askme

I lost my battery and then Alternator. Once I watched enough video to understand the slip bolts and how to don them, replacing the alternator as like a 45 min job for an idiot with the wrong tools. Do it to get peace of mind.

Originally Posted by dfwashere

Thats what i wanna hear lol. it def doesnt seem like a job thats too hard. thankfully access isnt too terrible like on other vehicles.

it wasn't bad at all. The biggest PITA was the bushing circled in red. The OEM alternator was tight because the bushing was expanded. It took some prying to get the old one out. Installing the new one was much easier.

[askme]

Those bushings slide into the block and lock it in place when the screws are tightened. when removing the alternator, you have to partially unscrew the bolts and give them a tap to push the bushings out of the socket. Makes much more sense when you are actually looking at it, but hard if you don't already have the spare as you can't really see this spot in the car.

[dfwashere]

Originally Posted by Denny347

it wasn't bad at all. The biggest PITA was the bushing circled in red. The OEM alternator was tight because the bushing was expanded. It took some prying to get the old one out. Installing the new one was much easier.

yeah some of these are a real PITA no matter the car. hopefully, mine goes will lol. thanks for the tip though!

[dfwashere]

alternator swap went will along with the upper radiator hose since i cracked the nipple lol. rip. 45 mins swap otherwise. thanks for the help and suggestions everyone!