[izewat]

Hi, this is my first post on the forum. I’ve recently bought an e92 330d lci. The previous owner had the battery changed by Halford’s not too long ago. I’m assuming it hasn’t been coded to the car. The alternator constantly whines even on idle. They told me that before the battery was changed it was on 8%. So this has me wondering whether the car doesn’t realise the battery is new, so the alternator is constantly trying to send power to the battery. Is there a way to code the battery? Also an OBD scanner said the battery is at 11.8V which seems low.

Any suggestions for what I can do to fix this would be much appreciated. Thanks

[lordnikon]

Test the charging voltage when the engine is running and report back. Yes the batt should be coded to the car.

[izewat]

Thanks. I’ll report back shortly. Would you recommend BimmerCode or bimmerlink? Or do you need both?

[lordnikon]

I use Protool. You can do coding as well as diagnostics.

[Mgh024]

Is it not a hardware issue (bearings, etc?)

[izewat]

Originally Posted by lordnikon

I use Protool. You can do coding as well as diagnostics.

Is this better than BimmerCode and BimmerLink? I don’t have any of them yet, so which one would you recommend?

[lordnikon]

Can't say which is better but Bimmercode only does coding and Bimmerlink only does diagnostics.

Protool does both if you get the Master licence and it's not subscription based.

[e90yyc]

Let us know if anything you do helps.

I feel like my alt is also noisy, but I’ve replaced it with a Bosch reman unit. Prior to that I had replaced it with a junkyard alt that I had rebuilt. My point is that enough alternators have been under my hood that whatever I think I’m hearing must surely be normal.

Not saying that’s the case with you though.

If I run my car without the accessory belt: dead quiet. With a belt but AC compressor bypassed: whine is present.

It does sound like my PS pump is also noisy, but like my alternator I’ve replaced it numerous times, and the unit in there now is a new(ish) OE LuK. Rack is reman too.

Anyway, not trying to derail your thread, but rather say I’ve got what I imagine to be a similar whine that I can’t seem to get rid of. Curious if alternator replacement would solve yours—assuming other measures don’t work.

[bmwbob89]

Use a stethoscope or a long screwdriver to your ear to pinpoint the noise.

[gbalthrop]

Originally Posted by lordnikon

Test the charging voltage when the engine is running and report back. Yes the batt should be coded to the car.

Originally Posted by izewat

Thanks. I’ll report back shortly. Would you recommend BimmerCode or bimmerlink? Or do you need both?

I would recommend a 10-Quid Multimeter:
https://www.amazon.co.uk/s?k=multime...f=nb_sb_noss_1

Any cheap multimeter will read DC Volts. That's "Direct Current Voltage", meter setting on 20V (or less) DCV. Measure with engine running at idle, at Jumpstart Terminals under the Hood/Bonnet. B+ is under Red Plastic cap, & use long Hex-pin on Wing (near B+) for (-) Chassis Ground.

In US, any large Auto Parts Chain will read Engine Module (DME) Fault Codes FREE. Check around in UK if don't know a chain there that provides such a service. Diagnosing a whining noise, a Scan Tool is NOT likely any help. Actual System Voltage with engine running & Alternator Charging is first test.

As others have suggested, a 5-Quid Mechanics Stethoscope is helpful for confirming that the noise comes from a particular component, & better yet, WHERE in that component. LOTS of folks throw parts instead of diagnosing. Don't be "those folks", unless you could care less, & have money to burn.

There is virtually NO WAY that failure to select correct "Battery Capacity" in the CAS Module would cause Alternator to have either Charging Issues, or Whining sound.

On E9x vehicles, if the replacement battery is a different TYPE, or more than 5 Ah Capacity Different from the battery replaced, then you MAY have to change the "Battery Capacity" setting in the CAS Module. Since the prior owner had the battery replaced, you need to know, related to battery currently installed:
1) Type: AGM or FLA (conventional Flooded Lead Acid)?
2) Ah (Amp-hour) rating, or at least Case Size.
If you have NO paperwork on current battery, you MAY get that information from the markings on the case of battery, or at least from the current ad for that Make/Model battery.

After getting THAT information, you would need to know what the current setting is in the CAS Module for Battery Type, AND Ah Capacity. That information also appears in the DME Engine Module, in the "PM"/ Power Module section of Live Data.

INPA (BMW Factory-Level Diagnostic Software), NCS Dummy (both of those are included in BMW Standard Tools), & some higher-end Scan Tools, will display the "PM" Data you need. For NOW, just do the Multimeter Voltage test & post back.

When you post back with System Voltage, motor running, please also indicate:
0) Last-7 Characters of VIN;
1) if the battery holds charge for at least 48 hours (sufficient to Crank Starter);
2) Whether or not there are any other "Startup" or performance issues.
George

[izewat]

Originally Posted by gbalthrop

I would recommend a 10-Quid Multimeter:
https://www.amazon.co.uk/s?k=multimeter&crid=M8MLVV2EM51N&sprefix=multimete r%2Caps%2C197&ref=nb_sb_noss_1

Any cheap multimeter will read DC Volts. That's "Direct Current Voltage", meter setting on 20V (or less) DCV. Measure with engine running at idle, at Jumpstart Terminals under the Hood/Bonnet. B+ is under Red Plastic cap, & use long Hex-pin on Wing (near B+) for (-) Chassis Ground.

In US, any large Auto Parts Chain will read Engine Module (DME) Fault Codes FREE. Check around in UK if don't know a chain there that provides such a service. Diagnosing a whining noise, a Scan Tool is NOT likely any help. Actual System Voltage with engine running & Alternator Charging is first test.

As others have suggested, a 5-Quid Mechanics Stethoscope is helpful for confirming that the noise comes from a particular component, & better yet, WHERE in that component. LOTS of folks throw parts instead of diagnosing. Don't be "those folks", unless you could care less, & have money to burn.

There is virtually NO WAY that failure to select correct "Battery Capacity" in the CAS Module would cause Alternator to have either Charging Issues, or Whining sound.

On E9x vehicles, if the replacement battery is a different TYPE, or more than 5 Ah Capacity Different from the battery replaced, then you MAY have to change the "Battery Capacity" setting in the CAS Module. Since the prior owner had the battery replaced, you need to know, related to battery currently installed:
1) Type: AGM or FLA (conventional Flooded Lead Acid)?
2) [...]

Hi, all of the specs of the battery are on the top so I will get back soon with what they are. Off the top of my head I know the battery is 92ah. I will attach photos below of multimeter readings. The voltage across the battery is with car off and key unplugged. The voltage across the alternator was with AC and lights off other than angels. I’m new to this so I can’t figure out how to attach a video with the sound I’m hearing on. Cheers
Edit: last VIN are E427029

[izewat]

[lordnikon]

12.67v when the engine is running? That's far too low. Voltage regulator and/or alternator is shot.

The whine issue may be alternator related but it could be something else.

[izewat]

Originally Posted by lordnikon

12.67v when the engine is running? That's far too low. Voltage regulator and/or alternator is shot.

The whine issue may be alternator related but it could be something else.

Yep very low. On previous e92 alternator went at 118k miles. Now this car is on 118k miles exactly too. Thought it was too much of a coincidence.

Battery is at 14.3V when idling.