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a whirring sound

Posted: Tue May 01, 2007 4:46 pm
by boxclever1753
hi guys

i have a whirring noise coming from the rear of my 1985 323. it is only audible over 30 ish mph and only when decellerating. i seem to remember a failing cv or uj joint sounding like this on another rear wheel drive car i had.

can anyone help? it is not vibrating the same i don't think but i haven't driven the car at speed yet and now don't want to until this is sorted.

thanks for your help in advance.

rich.

Re: a whirring sound

Posted: Tue May 01, 2007 9:10 pm
by jcjdavis1
Hi shoot me down in flames, but could it be a noisey fuel pump.

Re: a whirring sound

Posted: Tue May 01, 2007 10:19 pm
by boxclever1753
i had a noisy fuel pump in a previous 325i and that sounded more like an electrical hum - and was pretty much constant and noticeable on tickover which this isn't.

it ticks over quite high also - is that just a coincidence?

Re: a whirring sound

Posted: Tue May 01, 2007 10:22 pm
by jcjdavis1
Hi someone with more knowledge than me might help on that. Jim

Re: a whirring sound

Posted: Tue May 01, 2007 10:23 pm
by eko
Diff whine?

Re: a whirring sound

Posted: Tue May 01, 2007 10:25 pm
by Templ8e30
Classic symptoms of a noisy differential with failing pinion bearings.

It's unlikely to go bang on you but you should be on the lookout for a good replacement.

A good open diff (non-LSD) usually goes for £50 or so.

Cheers,

Iain T

Re: a whirring sound

Posted: Wed May 02, 2007 1:01 am
by Brianmoooore
It's a '85 car, so it has the two seperate fuel pumps set up. The pressure pump by the left wheelarch is fairly noisy normally, but is known to be noisier still if overloaded by failure of the in tank fuel pump.

Re: a whirring sound

Posted: Wed May 02, 2007 4:02 pm
by boxclever1753
but would the fuel pump thing be noticeable at idle? it isn't. and would it again only be noticeable when you have got up to speed and you decellerate?

is there anyone local who can have a drive and assess it for me?? some beer in it for ya ....

Re: a whirring sound

Posted: Wed May 02, 2007 7:23 pm
by boxclever1753
anyone?

Re: a whirring sound

Posted: Fri Jul 06, 2007 12:54 pm
by grimbo
I don't know if you are still interested but I had the same problem on my 89 325, it turned out to be the os rear wheel bearing.

I was afraid my diff was on the way out and was glad to get it fixed so easily/cheaply!

Re: a whirring sound

Posted: Fri Jul 06, 2007 2:02 pm
by tailoutcharlie
i have the same while on overrun and decelleration at high speed, im hoping its the diff and not a bearing....

perfect excuse for an LSD :D

Re: a whirring sound

Posted: Fri Jul 06, 2007 2:10 pm
by grimbo
I already have an LSD and really wasn't looking forward to the cost of replacing it.

I did research it though and these seem to be pretty good value:
http://www.diffsonline.com/product/used.shtml

From what I've read the "whining" noise seems to indicate a dodgy diff and from my experience a "whirring" noise is a bearing.

Re: a whirring sound

Posted: Fri Jul 06, 2007 3:58 pm
by tailoutcharlie
From what I've read the "whining" noise seems to indicate a dodgy diff and from my experience a "whirring" noise is a bearing.
is it worse whn you turn one way or t'other

Re: a whirring sound

Posted: Fri Jul 06, 2007 4:13 pm
by grimbo
which? the whirring?

I just replaced my exhaust (this morning in fact) and now that it's a lot quieter I may have been able to detect it at lower speeds but as it was given it was only really audible above 30mph I never really checked that out.

Also about 60mph I started getting a rythmic vibrating rumble that I could hear and feel through the floor pan. This has also disappeared with the new bearing.

So pretty happy with that fix all round.

Re: a whirring sound

Posted: Fri Jul 06, 2007 4:18 pm
by tailoutcharlie
result :)
my e30 fixes itself too, or maybe masks old noises with new more worrying ones :(

Re: a whirring sound

Posted: Fri Jul 06, 2007 8:19 pm
by ed325i
Has the diff got oil in it ?
I have a diff here off my 323 auto.