Alternator noise...

[e34.535i.sport]

I think there may be something wrong with the alternator - I get a loud screechy noise when driving with lots of electrics on e.g Radio, Full beams, heater, rear Demister... It screeches when my foot is on the acclerator, but stops when I take my foot off. I then tend to turn off the demister or whatever and the screeching goes and I can accelerate again without waking the dead... Its been really cold in the mornings lately too if that is relevant.

Is the alternator goosed or can I lubricate it with WD40 or something? If I need a new one is it a shop job or can I do it myself without too much hassle?

HELP!

[Ross]

The belt is loose.

[whiskychaser]

I think there may be something wrong with the alternator - I get a loud screechy noise when driving with lots of electrics on e.g Radio, Full beams, heater, rear Demister... It screeches when my foot is on the acclerator, but stops when I take my foot off. I then tend to turn off the demister or whatever and the screeching goes and I can accelerate again without waking the dead... Its been really cold in the mornings lately too if that is relevant.

Is the alternator goosed or can I lubricate it with WD40 or something? If I need a new one is it a shop job or can I do it myself without too much hassle?

HELP!
As Ross said its probably the belt thats loose. Not sure about yours but the M50 has a tensioner on it. Worth making sure thats working too. Its No. 20 in this:
http://www.realoem.com/bmw/showparts.do?model=HD68&mospid=47405&btnr=11_1344&hg=11&fg=18
If you dont know already, you can check the voltage (and therefore the alternator) using the OBC:
Push OBC buttons 1000 and 10 together. You will see the word Test. By pressing a combination of the 10 and 1's you can enter Test Codes from 1 to 21. After entering the number press R/S and you will get a continuous display of the test function. To cancel, just press any of the OBC function keys. It should be test 9 for voltage. HTH

[e34.535i.sport]

Thanks guys that would be a relief if the belt was loose, I think it does have a tensioner on it... I'll get in there and tighten it up see if the noise continues. Need some daylight and reasonable weather to get a good look in there. Seemed odd that it happened when there was more auxillaries on the go...

Hey Whiskey I've read up on the OBC testing before - I keep meaning to have a go of it because I'd find that really interesting... Just scared of finding anything wrong as I haven't had any repairs for a while touch wood - it is Winter!

Will report back once belt checking has taken place...

[DaveVoorhis]

Seemed odd that it happened when there was more auxillaries on the go...
That's to be expected. The more electrical load you put on the alternator, the more effort it takes to turn, and the more likely a loose belt is to slip.

[icesoft]

Belt's loose, no automatic tensioners on the M30 motor, it's all v-belts. It should be pretty easy to retension provided nobody stripped the teeth off the adjuster.

[whiskychaser]

Hey Whiskey I've read up on the OBC testing before - I keep meaning to have a go of it because I'd find that really interesting... Just scared of finding anything wrong as I haven't had any repairs for a while touch wood - it is Winter!


Ignorance isnt always bliss:) give it a go! It tells you the voltage at point R (wherever that it!) I dont find it as accurate as my DMM across the battery but its a good indication and saves you taking the back seat out if your battery is under it. Strangely enough, its winter here too!:)

[e34.535i.sport]

Update - it does seem to be when i'm using the rear demister... This seems to kick it off good style.

Makes perfect sense when you put it like that Dave thanks!

Thanks Ice'- I'm sure I read you simply loosen the adjucter nut (or whatever it is) then move it to the desired position and re-tighten am I right?!

Hey Whiskey thanks again, I'll make sure I get round to it over Christmas! Always good to hear from you!

[whiskychaser]

Update - it does seem to be when i'm using the rear demister... This seems to kick it off good style.

Makes perfect sense when you put it like that Dave thanks!

Thanks Ice'- I'm sure I read you simply loosen the adjucter nut (or whatever it is) then move it to the desired position and re-tighten am I right?!

Hey Whiskey thanks again, I'll make sure I get round to it over Christmas! Always good to hear from you!
Just had a look at Bentleys and Icesoft is right on the money. Bentleys is very vague but there is an ajuster somewhere!! To check your voltage output you have to press 4 buttons on the OBC. Thats your homework for xmas. Ofsted are aware:)

[e34.535i.sport]

Just had a look at Bentleys and Icesoft is right on the money. Bentleys is very vague but there is an ajuster somewhere!! To check your voltage output you have to press 4 buttons on the OBC. Thats your homework for xmas. Ofsted are aware:)

Hahaha LOL its funny you should say that, we had those er... people in recently!

Will report back once I've done my homework Sir! :D