Quick question

Can a bad alt (or going bad) for the m62 cause the engine to suddenly stall/turn off? Or would this be related more directly to the ignition system.
88k. I have no service records or codes.

When my alternator bearings were dying, my car would stall at idle at a light. This was due to the massive drag induced on the rotating parts, as well as reduced power to the coils (battery supplying all of the juice and not getting replenished).

You had the conventional alt with the brushes or the water-cooled?

water cooled, V8.

Thnks.. I guess Im going to be changing mine soon.

Originally Posted by Coochie_Bandit

Can a bad alt (or going bad) for the m62 cause the engine to suddenly stall/turn off?

Why not?

Typically, when an alternator fails, the red light goes on, and soon (if not already), the engine dies, with a host of temporary oddities due to the low voltage (e.g., trans failsafe).

Why not just charge the battery at home and then get the free alternator & charging system test?

Originally Posted by bluebee

Why not just charge the battery at home and then get the free alternator & charging system test?

Ive already done both battery and alt test. Alt is charging battery and battery is hold proper voltage..

But as mentioned earlier I think the alt is developing a bad bearing , causing the red light stalls.

Originally Posted by Coochie_Bandit

Ive already done both battery and alt test. Alt is charging battery and battery is hold proper voltage...I think the alt is developing a bad bearing , causing the red light stalls.

Hmmm.... something doesn't add up.

If the alt were 'intermittent', it wouldn't make a bit of difference because (AFAIK) the battery would/should take over whenever the alternator temporarily conked out. (QUESTION TO TEAM: Is that correct?)

Plus, you'd also have a red light on your dash at the times the alternator stopped producing current, so, in theory, you'd KNOW when the alternator 'intermittently' stopped producing output.

Of course, for many of us, that red light doesn't show up until it's far too late (ask me how I know):
- One users' example of total electrical failure (AAA towed away) alternator repair (1)

If you think it's the bearing, see these DIYs found by typing /alternator F3 in the VERY best of E39 Links

- How to test your generator (1) & how to determine exactly what alternator you have (1) & a DIY for replacing the E39 I6 alternator (1) (2) (3) (4) (5) or E39 V8 alternator (1) (2) (3) (4) & why rebuilding an alternator is preferable to replacing (1) & cn90 DIYs for rebuilding a 1998 air-cooled BMW Bosch alternator (1) (2) or his VW Bosch alternator (1) & cdawg246's quest for materials for a Bosch water cooled alternator rebuild (1) & Aioros' 1999 Valeo Alternator rebuild DIY (1) and his quest for materials (1) & Cn90's explanation of where to get hard-to-get alternator rebuild parts (1) & how to tell from the part number if a replacement alternator is actually rebuilt "by" Bosch (1) & a DIY for replacing the brushes in an (Audi) Valeo alternator (1) & a Bosch alternator bearing replacement from a 1997 MB S600 (1) & from a Range Rover (1).

EDIT: Please correct your title of this thread as everyone has a 'quick question'. You should put 'alternator' and/or 'bearings' in the title so that it is useful in the future and so that it doesn't waste our time revisiting (as we clue off the titles).