Battery woes / alternator perhaps? E63 M6

[magnus911]

So, I'm starting a new thread as this appears to be a new problem!

Recently, as I'm driving, the iDrive will keep switching itself off and immediately rebooting. This includes the HUD.

This is then followed by a loss of power steering and cruise control, neither of which will work until the ignition is turned off and on.

I also sometimes get a message to check battery terminals at the same time.

Car is 2005/6 with 40k.

Could it be the battery? Or perhaps the alternator?

Car is under warranty but 250 excess means it might be worth just changing the battery to see if it helps. Does that sound wise? Is there another way to troubleshoot the battery or alternator?

Thanks in advance. If I should get a battery, any suggestions for a good one?

[omniflow]

Check for water in the boot.

Not sure if the layout is the same as the e61 M5, but it sounds like part of the problem I had when there was about 1" of water in the "wheel well" (quoted, because there's not actually room for a wheel in there, but it's the closest description). In the e61 it's because of sunroof drains, no idea in an M6.

[Ocarru]

Magnus, there's no surefire way but get an indie to do a diagnostic check and they'll stick a multimeter on the battery to confirm the strange voltages - if that's the case. I'm sure the mechanic told me the batteries were good but relatively expensive.

Right, that's it, I'm not stalking this issue anymore! Mine chose to go wrong as a mate got in my car for the first time and he is still taking the mickey out of me every time I see him. Don't let this happen to you!

Edited to add: the indie put my battery on charge to make absolutely sure. This might be worth a try, mine went bonkers about 5 minutes later as it was becoming more frequent.

Edited by Ocarru on Monday 6th February 21:22

[magnus911]

Thanks for your replies guys. Will check to see if any water has collected in the back tomorrow am, but there's no sun roof so perhaps not.

Good call on the multimeter and the battery. Prob worth checking before entrusting it back to BMW!

[Rich_R]

My idrive rebooted itself this morning whist on the go. First time that's happened! E63's don't seem to like the cold - idrive slower to start up and sat nav can take a few mins to display map when sub zero...

R

[Cheburator mk2]

If you change the battery, make sure you tell the car that you have done so. E60/61/63s charge their batteries intelligently and need to be told the amperage and whether the battery is new... A good indy would know what to do...

[systemv]

I know its an old thread. Same problem driving me nuts!!!! Power goes down randomly, idrive reboots. Have you been able to figure out what was the problem? Thank you!