1989 325i making unearthly noise under the engine

Let me try to describe the sound. It doesn't happen all the time,
just after a lot of driving. Occurs when turning, especially on
uneven road surfaces. It can happen when I brake, though I don't
think it's the brake pad sound. It can continue even after I have
fully braked, and the car is standing still. It can happen when I
decelerate, am close to braking.
It seems to come from the middle front, i.e., almost under the
airconditioning system. Perhaps a little on the left, though it's
hard to tell. It's not quite grinding, not quite clanging, not quite
rattling, not quite groaning/moaning, though a little of all of
these. Definitely metallic. The best I can describe is it sounds
like a plane going overhead, and I often have to look if there's a
plane, or a truck or something beside or behind me making the sound.
Recently the car was parked for almost 2 mos., during Houston 100
degree heat, at a stupid mechanic's. The noise started after that.
I'd really appreciate help as to what this might be. Before I take in
to another mechanic, not the same one.
Thank you!

Kind of hard to tell with that explanation but I'd look real hard at
the motor mounts. If your engine is moving around it can make all
kinds of bad sounds. If you still have the original mounts they are
ripe for a failure.

RJD

On Mon, 24 Aug 2009 23:21:04 -0700 (PDT), AnisShivani
> wrote:

>Let me try to describe the sound. It doesn't happen all the time,
>just after a lot of driving. Occurs when turning, especially on
>uneven road surfaces. It can happen when I brake, though I don't
>think it's the brake pad sound. It can continue even after I have
>fully braked, and the car is standing still. It can happen when I
>decelerate, am close to braking.
>It seems to come from the middle front, i.e., almost under the
>airconditioning system. Perhaps a little on the left, though it's
>hard to tell. It's not quite grinding, not quite clanging, not quite
>rattling, not quite groaning/moaning, though a little of all of
>these. Definitely metallic. The best I can describe is it sounds
>like a plane going overhead, and I often have to look if there's a
>plane, or a truck or something beside or behind me making the sound.
>Recently the car was parked for almost 2 mos., during Houston 100
>degree heat, at a stupid mechanic's. The noise started after that.
>I'd really appreciate help as to what this might be. Before I take in
>to another mechanic, not the same one.
>Thank you!

On Aug 25, 8:59*pm, RJD > wrote:
> Kind of hard to tell with that explanation but I'd look real hard at
> the motor mounts. If your engine is moving around it can make all
> kinds of bad sounds. If you still have the original mounts they are
> ripe for a failure.
>
> RJD
>
> On Mon, 24 Aug 2009 23:21:04 -0700 (PDT), AnisShivani
>
> > wrote:
> >Let me try to describe the sound. *It doesn't happen all the time,
> >just after a lot of driving. *Occurs when turning, especially on
> >uneven road surfaces. *It can happen when I brake, though I don't
> >think it's the brake pad sound. *It can continue even after I have
> >fully braked, and the car is standing still. *It can happen when I
> >decelerate, am close to braking.
> >It seems to come from the middle front, i.e., almost under the
> >airconditioning system. *Perhaps a little on the left, though it's
> >hard to tell. *It's not quite grinding, not quite clanging, not quite
> >rattling, not quite groaning/moaning, though a little of all of
> >these. *Definitely metallic. *The best I can describe is it sounds
> >like a plane going overhead, and I often have to look if there's a
> >plane, or a truck or something beside or behind me making the sound.
> >Recently the car was parked for almost 2 mos., during Houston 100
> >degree heat, at a stupid mechanic's. *The noise started after that.
> >I'd really appreciate help as to what this might be. *Before I take in
> >to another mechanic, not the same one.
> >Thank you!

Could it some suspension part that's dried up because the car stood
for so long?
And just needs to be lubricated? I'd guess it's something frozen, or
has come loose,
because they didn't reassemble things properly. By the way, they were
working on the
a/c for all that time. How about a loose wheel bearing? Is that
possible?

On Aug 25, 1:21*am, AnisShivani > wrote:
> Let me try to describe the sound. *It doesn't happen all the time,
> just after a lot of driving. *Occurs when turning, especially on
> uneven road surfaces. *It can happen when I brake, though I don't
> think it's the brake pad sound. *It can continue even after I have
> fully braked, and the car is standing still. *It can happen when I
> decelerate, am close to braking.
> It seems to come from the middle front, i.e., almost under the
> airconditioning system. *Perhaps a little on the left, though it's
> hard to tell. *It's not quite grinding, not quite clanging, not quite
> rattling, not quite groaning/moaning, though a little of all of
> these. *Definitely metallic. *The best I can describe is it sounds
> like a plane going overhead, and I often have to look if there's a
> plane, or a truck or something beside or behind me making the sound.
> Recently the car was parked for almost 2 mos., during Houston 100
> degree heat, at a stupid mechanic's. *The noise started after that.
> I'd really appreciate help as to what this might be. *Before I take in
> to another mechanic, not the same one.
> Thank you!

I had similar sounds and it ended up being a bad alternator along with
bad pulleys/bearings.
How many miles on car?
I've learned bmw autos have weak cooling systems (factory). Also
alternators and the pulleys/bearing don't last as long as japanese
cars.
I've seen them go about every 35k or so. Japanese alternators,
pulleys and bearing usually go over 100k miles.
since u car is 89 model, I'd also look at motor mounts, suspension
bushings too.

However the sound u describe sounds like something spinning at high
speed that has broken.

Good luck!!

Oskar

On Aug 26, 6:43*pm, " > wrote:
> On Aug 25, 1:21*am, AnisShivani > wrote:
>
>
>
> > Let me try to describe the sound. *It doesn't happen all the time,
> > just after a lot of driving. *Occurs when turning, especially on
> > uneven road surfaces. *It can happen when I brake, though I don't
> > think it's the brake pad sound. *It can continue even after I have
> > fully braked, and the car is standing still. *It can happen when I
> > decelerate, am close to braking.
> > It seems to come from the middle front, i.e., almost under the
> > airconditioning system. *Perhaps a little on the left, though it's
> > hard to tell. *It's not quite grinding, not quite clanging, not quite
> > rattling, not quite groaning/moaning, though a little of all of
> > these. *Definitely metallic. *The best I can describe is it sounds
> > like a plane going overhead, and I often have to look if there's a
> > plane, or a truck or something beside or behind me making the sound.
> > Recently the car was parked for almost 2 mos., during Houston 100
> > degree heat, at a stupid mechanic's. *The noise started after that.
> > I'd really appreciate help as to what this might be. *Before I take in
> > to another mechanic, not the same one.
> > Thank you!
>
> I had similar sounds and it ended up being a bad alternator along with
> bad pulleys/bearings.
> How many miles on car?
> I've learned bmw autos have weak cooling systems (factory). *Also
> alternators and the pulleys/bearing don't last as long as japanese
> cars.
> I've seen them go about every 35k or so. *Japanese alternators,
> pulleys and bearing usually go over 100k miles.
> since u car is 89 model, I'd also look at motor mounts, suspension
> bushings too.
>
> However the sound u describe sounds like something spinning at high
> speed that has broken.
>
> Good luck!!
>
> Oskar

Thanks for your thoughts.
The car has around 180,000 miles on it. I've had it for ten years and
never replaced the alternator, or pulleys/bearings. It's generally
trouble-free, unless the mechanic messes it up, makes it worse than
when I left it there. I still think something dried when it was
parked for 2 mos., and perhaps has broken now. Is suspension bushing/
mounts/bearings work expensive to fix?

In article
>,
> wrote:
> I've learned bmw autos have weak cooling systems (factory). Also
> alternators and the pulleys/bearing don't last as long as japanese cars.
> I've seen them go about every 35k or so.

New one on me. The alternator maker supplies others too.

> Japanese alternators,
> pulleys and bearing usually go over 100k miles.

Don't think I've ever had an alternator bearing fail. Electronic failure
usually gets them first. The one on my E34 525 failed at approx 150,000
miles - and I could probably have fixed it but had to have it replaced
since it failed some way from home. The most likely failure is the
regulator followed by the diode pack. Never seen worn out brushes either.

Later engines have problems with the idler pulleys.

--
*Never put off until tomorrow what you can avoid altogether *

Dave Plowman London SW
To e-mail, change noise into sound.