BMW M5 Forum and M6 Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
85 Posts
Discussion Starter #1
Hey guys,

While gunning it a bit on Friday I suddenly had the red battery sign pop up on the dash. As I stopped at a traffic light I could also hear a whine coming from the engine.
Being close to home I idled there and took a look. The noise seems to come from the front right of the engine. It is only audible when the belts are turning. Both belts look fine and in decent nick. Also not slipping...

With the battery light on, I assume it must be the alternator? And apparently that is quite a tedious job.

Has anyone had a similar experience? Any other ideas on what the problem might be if not the alternator? And are there any threads that someone can remember showing a DIY replacement?
 

·
Registered
Joined
·
85 Posts
Discussion Starter #3
When I went into the secret menu, test 9 voltages displayed at 10.6 . when driving it it goes up to 11.2 and then back to the high 10's.
 

·
Registered
Joined
·
7 Posts
My problem is somehow related to yours. I hear a distinct and continuous whining noise at all revs especially at low revolutions. It seems like the engine is high-pitched than usual. My battery light flashes on and off for a second. I just got a new battery and my oil is all good. I think it may be an alternator problem as I have read some post related to our problem on BMW repair. It makes sense since the whining noise increases along with the engine revs.
 

·
Registered
Joined
·
1,355 Posts
Sounds like a alternator, I've had that noise on another car, same symptoms whine light flashing, I've been told most likely when the light flashes it is always the alternator and not the battery. For those that are having this problem it seesm either it is at the verge of failing since you guys are still able to drive it with it not charging that much, it will leave you stranded I've learned the hard way b4.
 

·
Registered
Joined
·
1,683 Posts
When I went into the secret menu, test 9 voltages displayed at 10.6 . when driving it it goes up to 11.2 and then back to the high 10's.

the alternator is shot.worn out. best thing too do is refurb it /get a refurbed one-or a new alternator(800$$$) iff you dont want too wait for the refurb.


iff you have ramps or lay under the car you can remove it..its not that big off a deal..

remove your positive lead on the battery, so the power is off the car!!!
remove underbody panels.
then check AND memorize how the belt is running..
then attack:hihi: your powersteering pulley, loosen it, there are 3 bolts on there.just be carefull because the pulleys tend too brake in worst cases from heat infusion over the years.
once removed the 3 bolts,the pulley should come off with some force..just be carefull you dont brake it.
now go for the belt tensioner pulley,there s a shield covering the pulley.
pulley is tight with a torx bolt.
once that one is loose, the belt schould come right off.

now you can acces the alternator. its locked in place with 2 bolts..18mm. remove those , remove the powerleads on the alternator.schould be 3 separate wires iff i remember correct ..its a bit off a pain because you dont have mutch room. but its possible with some patience.
then pull the alternator from underneath the car..job done


mounting new one,

get it under the car , mount it in place( loose so you have your hands free too work the rest) reconnect the wires, bolt it on again. put serpentine belt back on like it was, bolt your powersteering pulley back on, tighten the belt tensioner down,look iff the belt is tight enough..(iff your belt is cracked or has signs off cracks , just put a brand new on one ..not that expensive ) it should have a little movement when you pusch it with your finger, so not too tight also. put protective shield back on,

re-check every step again iff you didn't forget something, or have parts left over:hihi:

put underpanels back on, put powerlead back on the battery terminal in the trunk, start the car

done.


alternator refurb schould set you 300$ back.. and 2h labour iff your handy..
or just buy a refurbed alternator and drop it off at your indy/dealer and let them take care off it for you.
 

·
Registered
Joined
·
1,683 Posts
Sounds like a alternator, I've had that noise on another car, same symptoms whine light flashing, I've been told most likely when the light flashes it is always the alternator and not the battery. For those that are having this problem it seesm either it is at the verge of failing since you guys are still able to drive it with it not charging that much, it will leave you stranded I've learned the hard way b4.

the reason the light begins too flash is indeed because the alternator is almost done..


the axle where the pulley is on, has a little tension on from the belt..after time the axle begins too wear out from that tension and instead off turning in circles it goes on a oval movement.the internals begin too wear out and when its almost done it only touches the coil on the side where the most tension is on still.. so instead of full charge in circels where it touches the coil everywhere, it goes charge-not charge-charge-not charge in oval movement..

the battery slowley gets out off juice after a while and the light begins too blink, warning you it doesn't get electrical supply enough too operate.
iff someone ever have this on a trip , try too stay under 2000 rpm..the car will use almost no power and you can (fingers crossed) get home most off the time.. although at that point everything is a gamble offcourse:biggrin:
 

·
Registered
Joined
·
85 Posts
Discussion Starter #8
Thanks for the advice ;)

Will remove and take it in for a refurb
 

·
Registered
Joined
·
1,195 Posts
I did my alternator from the top, quite easy really...don't really have to remove or drain anything besides the intake on that side. South Africa has right hand drive though right? Not sure how that would affect things?
 

·
Registered
Joined
·
374 Posts
The voltage in my car reads 13.8 via the secret menu. The battery has 12 volts - if your menu is reading less than 12 volts, you've got a serious drain on the electrical system, i.e. you alternator isn't doing squat! If you keep driving much longer you'll kill your big expensive battery.
 

·
Registered
Joined
·
85 Posts
Discussion Starter #11
Yeah, Right hand drive. I'll tackle it as soon as I get a large enough spanner to undo the fan :p

And yes, it did fail on me :p First time the M5 left me next to the road... Charge went from an avg of 10.4-11 to 7 and died. Will be ripping out the alty over the weekend and either refurbing or buying a new / refurbed unit. Got a quote of $220 with shipping of a refurbed unit.
 
1 - 12 of 12 Posts
Top