Noise on BMW

from_atozinc

My better half has a 2008 BMW 320d saloon.
She has this weird problem with the car. This problem is intermittent.

So here is the problem, she will be driving along fine on a straight road with no issues , then comes to a speed ramp, does the usual, slows down, front wheel goes over the ramp fine, then back wheel goes over ramp and when back wheel exits off the speed ramp, this is when the car makes the noise. This noise sounds like its something that's loose and sounds like its coming from the back right of the car.
I've brought it back to the dealers twice and they could not find an issue

I know it seems relatively minor but It's seriously annoying when it happens , just sounds like something is very loose.

And it only happens about 40% of the time, can happen on shallow speed ramps, steep ones and occasionally when you hit a bad bump in the road.

I've looked on the underside of the car and couldn't see anything loose. When the car is stationery I've bounced the car up and down on all 4 corners but couldn't replicate the noise.

Anyone have any other ideas ?
Or experienced an issue like this on a BMW ?

corkgsxr

Check bushings. Youll need to put it up on a jack to take pressure off them to see movement

from_atozinc

corkgsxr wrote: »

Check bushings and shocks.

Sorry for my ignorance here. So I know the shocks but where are the bushings ?

kirving

Bushings are basically plastic or rubber bearings, which are used to cushion vibrations. Over time, they wear out and need to be replaced. When this happens, the two metal parts can touch off one another, and create a kind of knocking sound.

http://classic.artsautomotive.com/Bushing.jpg

from_atozinc

Thanks so far

The sound I'm hearing when the car exits the ramp is kinda like an empty metal tank rattling up and down if that makes any sense.

So don't know if its anything to do with bushings.

Big Nasty

from_atozinc wrote: »

Thanks so far

The sound I'm hearing when the car exits the ramp is kinda like an empty metal tank rattling up and down if that makes any sense.

So don't know if its anything to do with bushings.

Definitely sounds like worn bushings. I.e. the control arms / links are banging off each other due to worn out rubber.

from_atozinc

MCMLXXV wrote: »

Definitely sounds like worn bushings. I.e. the control arms / links are banging off each other due to worn out rubber.

As you can tell, I don't know much about bushings ; )

The noise sounds like the fuel tank attached to the car is just totally empty and that it is loose. And then when driving over the ramp, the whole petrol tank and exhaust system rattles - that's how the noise sounds to me. Well maybe not rattle but just shakes up and down.

But if worn bushings could make a similar then I'll get them checked.

Big Nasty

All suspension parts and steering components have bushings. Basically they are rubber (or sometimes poly) washers that stop metal parts banging off one another. Hence a worn bushing will give the rattle you described, especially over bumps, potholes and ramps.

kirving

Maybe get another mechanic to drive the car over a few ramps to be sure too. Sounds like that on my Dad's Focus, which seems to go through a lot of anti-roll bar bushings. They are cheap replacements though.

dharn

Kevin Irving wrote: »

Maybe get another mechanic to drive the car over a few ramps to be sure too. Sounds like that on my Dad's Focus, which seems to go through a lot of anti-roll bar bushings. They are cheap replacements though.

Later description of noise sounds more like the exaust silencer banging off something bushings would give a dull thumping sound not ahollow rattling

from_atozinc

Kevin Irving wrote: »

Maybe get another mechanic to drive the car over a few ramps to be sure too. Sounds like that on my Dad's Focus, which seems to go through a lot of anti-roll bar bushings. They are cheap replacements though.

Thanks again

Thing is the feckin thing is intermittent. I sometimes wish it was there the whole time to allow me to re priduce it. When I wanted the noise too happen it dosent - I couldn't reproduce the bloody issue for the garage which did my fcukin head in.
Maybe the speed ramp has to be certain angle or something for it to happen.

How much are we talking to fix this ( parts and labour ) - if it is the bushings ?

And how many bushings does a car have ?

from_atozinc

dharn wrote: »

Later description of noise sounds more like the exaust silencer banging off something bushings would give a dull thumping sound not ahollow rattling

mmmmm. The sound just sounds like something loose. It dosent make a continuous rattle. Just one rattle kind of up and down as the car exits the ramp.

Stheno

from_atozinc wrote: »

mmmmm. The sound just sounds like something loose. It dosent make a continuous rattle. Just one rattle kind of up and down as the car exits the ramp.

This may sound like a really stupid suggestion, is there any possibility the spare wheel is loose and depending on how much of a wallop the ramp exiting causes is shaking about in the boot? Or any related tools?

Edit: Forgot about runflats, ignore if that's the case

sunnysoutheast

from_atozinc wrote: »

Thanks again

Thing is the feckin thing is intermittent. I sometimes wish it was there the whole time to allow me to re priduce it. When I wanted the noise too happen it dosent - I couldn't reproduce the bloody issue for the garage which did my fcukin head in.
Maybe the speed ramp has to be certain angle or something for it to happen.

How much are we talking to fix this ( parts and labour ) - if it is the bushings ?

And how many bushings does a car have ?

If it's at the rear and you've eliminated everything else try pulling on the handbrake one/two notches or lightly apply the brakes, go over a speed bump and see if it goes away - the pads can sometimes chatter against the caliper - the fix I think is supposed to be grease or "stop-squeak" between them. Other option is an internally broken shock absorber.

Tails142

Had a problem like this before and it was a stone on the sump cover, try checking if it ssomething like that

from_atozinc

Stheno wrote: »

This may sound like a really stupid suggestion, is there any possibility the spare wheel is loose and depending on how much of a wallop the ramp exiting causes is shaking about in the boot? Or any related tools?

Edit: Forgot about runflats, ignore if that's the case

; ) yeah, there is no spare

I checked the area too where the spare wheel would normally be and no evidence of anything loose and also checked for anything loose in the general boot area

from_atozinc

sunnysoutheast wrote: »

If it's at the rear and you've eliminated everything else try pulling on the handbrake one/two notches or lightly apply the brakes, go over a speed bump and see if it goes away - the pads can sometimes chatter against the caliper - the fix I think is supposed to be grease or "stop-squeak" between them. Other option is an internally broken shock absorber.

I think the noise is coming from the back right. But I've been wrong before with where a noise was coming from on a car I had about 8 years ago........I was sure a noise was coming from back left but it was actually front left ! So I fecked that one up.

I'll try what you said and see if it can bring me closer to resolving this annoying issue

I know I may be blowing things out of proportion............but when I drive over a ramp and I hear this noise, it just really wrecks my head - and then the fact that I've been to a garage twice and I could not reproduce the issue and they couldn't find an issue.

ian87

I replaced two upper rear control arms in my 08 320d today. I had a rattle which sounded like it was coming from the rear wheel well. Wasnt too expensive, 1.5 hours labour plus parts.
Apparently being rwd these cars are harder on your rear suspension parts than other cars..

from_atozinc

ian87 wrote: »

I replaced two upper rear control arms in my 08 320d today. I had a rattle which sounded like it was coming from the rear wheel well. Wasnt too expensive, 1.5 hours labour plus parts.
Apparently being rwd these cars are harder on your rear suspension parts than other cars..

Did your noise sound anything like the one I described and was it reproduce able at will ?

Stheno

from_atozinc wrote: »

Did your noise sound anything like the one I described and was it reproduce able at will ?

I've had bushes problems in a different car from yours and to be honest it was always there, that's why I posted about something loose in your car.

Mechanic found it first time I brought it in.

Did your mechanic hoist the car up and check the suspension?

from_atozinc

Stheno wrote: »

I've had bushes problems in a different car from yours and to be honest it was always there, that's why I posted about something loose in your car.

Mechanic found it first time I brought it in.

Did your mechanic hoist the car up and check the suspension?

I took it for a drive and could not re produce. I then left it to them to have a look and didnt wait around while they did the work as I had limited time on both occasions.......so didnt even get to see if they hoisted it up But they said they did.......

Stheno

When did it last pass the NCT?

from_atozinc

Stheno wrote: »

When did it last pass the NCT?

Jan 2012, she only has it 9 months like

mb1725

sunnysoutheast wrote: »

If it's at the rear and you've eliminated everything else try pulling on the handbrake one/two notches or lightly apply the brakes, go over a speed bump and see if it goes away - the pads can sometimes chatter against the caliper - the fix I think is supposed to be grease or "stop-squeak" between them. Other option is an internally broken shock absorber.

I had an intermittent rattle from the rear of an e90 and it did turn out to be one brake pad.



The silver anti-rattle clip had parted company with the pad.

sunnysoutheast

mb1725 wrote: »

I had an intermittent rattle from the rear of an e90 and it did turn out to be one brake pad.


The silver anti-rattle clip had parted company with the pad.

Mine's a B6 Audi and while it was up for tyres the mechanic checked all the bushes, exhaust, etc. and eventually he suggested the rear brake after driving it. Doesn't happen the same way on the front as you've usually braked coming up to the bump.

I've had the rattle on-and-off for a while now, it's funny how the noise travels and sounds like anything other than a brake!

Not sure if there is a spring or not in mine but as the fix is basically the same level of effort as replacing the rear pads I decided to leave it until they need changing. I'll be chopping the car in soon anyway so not sure if I'll get round to fixing it.

from_atozinc

Thanks for all the replies

I drove in to work today with the BMW and went over the same speed ramps and not a budge , no bloody noise at all today.
I encounter about 15 of these speed ramps on my drive to work

And yesterday, I drove over the exact same speed ramps and every bloody speed ramp I drove over it made the noise.......weird the way it comes and goes

but seriously does me head in when it happpens

furtzy

from_atozinc wrote: »

Thanks for all the replies

I drove in to work today with the BMW and went over the same speed ramps and not a budge , no bloody noise at all today.
I encounter about 15 of these speed ramps on my drive to work

And yesterday, I drove over the exact same speed ramps and every bloody speed ramp I drove over it made the noise.......weird the way it comes and goes

but seriously does me head in when it happpens

Had several of these over the years and it wrecks your head. I've learnt the best thing to do is turn the radio up and wait until the noise is there all the time and then go to a mechanic

from_atozinc

could be right there furtzy, but in sayin that, the noise, when it happens dosent sound right either, im hoping its not causing damage to the car.

ive got to the stage where I dont even have the radio on as im listening out for this fookin noise the whole time

eddiem74

from_atozinc wrote: »

Thanks for all the replies

I drove in to work today with the BMW and went over the same speed ramps and not a budge , no bloody noise at all today.
I encounter about 15 of these speed ramps on my drive to work

And yesterday, I drove over the exact same speed ramps and every bloody speed ramp I drove over it made the noise.......weird the way it comes and goes

but seriously does me head in when it happpens

I suspect speed and weather is also a factor, the wet weather could be hiding (acting like a lube) or intensifying it.

I have some similar creaks/squeaks in my 08 325 front suspension and research is pointing to dampers/bump stops or ARB bushes.

from_atozinc

eddiem74 wrote: »

I suspect speed and weather is also a factor, the wet weather could be hiding (acting like a lube) or intensifying it.

I have some similar creaks/squeaks in my 08 325 front suspension and research is pointing to dampers/bump stops or ARB bushes.

So much for ultimate driving machine ; )

from_atozinc

I brought me car in to a another garage and they checked everything and couldnt find an issue.
Ive done a video of me driving over ramps to demonstrate the noise.
It maybe hard to pickup the noise and you need to have your speakers on full volume to hear it
And it dosent happen over all the ramps, only some - pain in me bollix
The noise happens at 5 seconds and 13 seconds

http://youtu.be/PjC-SAzD-eQ

sebastianlieken

ha, you know I had a similar issue just the other day. Turns out there was a loose aerosol can in the boot. that was a pretty easy fix!

The point of me writing that is to make sure you're not overlooking the simple things.

Nothing loose in boot?, Spare wheel and tools fastened correctly so they're not moving about?, the exhaust isn't loose?

edit: ah, I see someone has already posted this (more or less)

Have the spring coils been looked at? it's not uncommon for the pig-tails on them to snap.

from_atozinc

sebastianlieken wrote: »

ha, you know I had a similar issue just the other day. Turns out there was a loose aerosol can in the boot. that was a pretty easy fix!

The point of me writing that is to make sure you're not overlooking the simple things.

Nothing loose in boot?, Spare wheel and tools fastened correctly so they're not moving about?, the exhaust isn't loose?

a very easy fix
Ya I checked the boot and nothing loose.
I have no spare wheel, tools are fastened.
Mechanic checked exhaust and said it was fine

Plug

Sounds like a thinny single rattle sound. I wonder has a baffle broke off in the exhaust somewhere?

from_atozinc

Plug wrote: »

Sounds like a thinny single rattle sound. I wonder has a baffle broke off in the exhaust somewhere?

Yeah, thats about it alright. it just sounds to me like the petrol tank is loose or the exhaust is loose, but 2 mechanics have checked this now and say its ok
Also, weird the way it happens over the 1st ramp, then the 2nd ramp 5 seconds later it dosent happen and then the 3rd ramp it happens again and then the 4th ramp dosent happen
I dont know the answer to your question to be honest : )

sebastianlieken

Have you tried shouting and hurling hatelful abuse at it yet?

from_atozinc

sebastianlieken wrote: »

Have you tried shouting and hurling hatelful abuse at it yet?

Oh fook ya
Can you not hear me in the video at it ??

George Dalton

sebastianlieken wrote: »

Have the spring coils been looked at? it's not uncommon for the pig-tails on them to snap.

It certainly sounds like a coil spring issue but you would hope that would have been picked up pretty easily by one of the garages who looked at it

from_atozinc

George Dalton wrote: »

It certainly sounds like a coil spring issue but you would hope that would have been picked up pretty easily by one of the garages who looked at it

neither of the garages picked up anything obvoius - according to themselves

now I dont know how in depth they looked or how long they spent loooking

from_atozinc

Just looking over the posts from the start, these are the suggestions as to what the problem may be :

1. bushings
2. exhaust silencer banging off something
3. pads chattering against the caliper
4. stone on the sump cover
5. upper rear control arms
6. suspension
7. brake pads
8. dampers/bump stops
9. ARB bushes
10. baffle broke off in the exhaust
11. coil spring issue
12. Steering rack


Now with the help of the video : http://youtu.be/PjC-SAzD-eQ

What do you think is the most obvious cause of the issue ?

Or maybe, like everything, its just too hard to diagnose over d'interweb.

db

Have you tried taking a different route to work and staying away from the ramps? This is only slightly tongue in cheek as driving over 15 ramps each way every day is going to take a toll on your suspension.

from_atozinc

db wrote: »

Have you tried taking a different route to work and staying away from the ramps? This is only slightly tongue in cheek as driving over 15 ramps each way every day is going to take a toll on your suspension.

I know what your sayin. But id still like to try and fix the issue

Ive been doing this same route to work for years and never had this issue on my 3 older cars

8 of the ramps I go over anyways are within the business park I work in so are un avoidable.

sebastianlieken

Right, I just watched the video ( I was putting it off as i'm in work). That really sounds like a spring coil to me mate. Whether it's the front or rear you'll have to check yourself.

Front ones are easy to check, hard to see visually but easy to feel. Put your hand in above the top of the front wheel so you can feel the spring coil (looks like this) run your hand up and down to either end. what you're feeling for is a very jagged and rough end which would be indicitave of a snapped coil. if the ends feel smooth they should be alright.

The rear spring coil looks like this. These coils are much more difficult to check as they're inside the wheel arch (I think). But these are the spring coils that I think are making the noise.

The boring explanation: what happens is a spring wants to rotate a little bit when it is compressed (speed bump). BUT, the two smooth edges on either side of the spring create more than enough static friction with their respective houseings that the torsional load in the spring is absorbed by the spring elasticity itself (this condition is both ends fixed). What a broken spring coil does though is create a condition of one end fixed and one end free. The free end of the coil does not have enough static friction to withstand rotation and hence the free (broken) end does manage to rotate. It's this sudden release in torsional potential energy in the spring coil which creates a sudden metal on metal "clanking" sound as the free end moves accross it's housing.

There's 30 seconds of your life you're never getting back! :pac:

also, just to back up my own opinion, 30 speed bumps a day is definatly going to affect your suspension adversly. especially after the winter salt on the road, and even more if you have low profile alloys.

from_atozinc

sebastianlieken wrote: »

Right, I just watched the video ( I was putting it off as i'm in work). That really sounds like a spring coil to me mate. Whether it's the front or rear you'll have to check yourself.

Front ones are easy to check, hard to see visually but easy to feel. Put your hand in above the top of the front wheel so you can feel the spring coil (looks like this) run your hand up and down to either end. what you're feeling for is a very jagged and rough end which would be indicitave of a snapped coil. if the ends feel smooth they should be alright.

The rear spring coil looks like this. These coils are much more difficult to check as they're inside the wheel arch (I think). But these are the spring coils that I think are making the noise.

The boring explanation: what happens is a spring wants to rotate a little bit when it is compressed (speed bump). BUT, the two smooth edges on either side of the spring create more than enough static friction with their respective houseings that the torsional load in the spring is absorbed by the spring elasticity itself (this condition is both ends fixed). What a broken spring coil does though is create a condition of one end fixed and one end free. The free end of the coil does not have enough static friction to withstand rotation and hence the free (broken) end does manage to rotate. It's this sudden release in torsional potential energy in the spring coil which creates a sudden metal on metal "clanking" sound as the free end moves accross it's housing.

There's 30 seconds of your life you're never getting back! :pac:

also, just to back up my own opinion, 30 speed bumps a day is definatly going to affect your suspension adversly. especially after the winter salt on the road, and even more if you have low profile alloys.

sebastianlieken, thanks for taking the time to listen again and to write that up.

Ill try and have a look at this after work and see if I can find anything but I havent a great knowledge of parts in cars, but sure will give it a go anyways

So essentially what im checking for is to see if the spring coil has broken/snapped at some point - the srping is still acting as a cushion as such due to the natural weight of the car on it and without force being exerted on the spring or the spring being forced to bounce up and down there is no noise.............. but if it is indeed snapped and sudden force comes upon the spring ( driving over speed bump ) , the force will sometimes press the spring further down due to it being broken at a certain point and break in the spring is causing the noise - hope im making sense

thanks again.

from_atozinc

So in my head, when I think of "suspension", I think of springs

So are there 2 kinds of springs in a car ?

1. Spring Coil
2. Suspension springs

Or am I totally wrong
Told you I knew nothing about cars : )

sebastianlieken

yep that's pretty much the gist of it!

Sorry by the way if this isn't the problem (i'm not a wizard like) but it's what i'd be getting checked out. Pop into a garage and tell them you reckon one of the rear spring coils is buggered (or possibly one of the front ones).

Also just fyi; (and this is only if it is the spring coils) the garage will probably push to change both left and right coils even if only one is buggered. This in general is good practice to keep load distribution even. I'd say the garage bill would probably be around the €200 mark (maybe a bit more)

keep us posted anyway

Edit: "spring coils" and "suspension springs" are the same thing. Those links I put up, that's what they are.

from_atozinc

sebastianlieken wrote: »

yep that's pretty much the gist of it!

Sorry by the way if this isn't the problem (i'm not a wizard like) but it's what i'd be getting checked out. Pop into a garage and tell them you reckon one of the rear spring coils is buggered (or possibly one of the front ones).

Also just fyi; (and this is only if it is the spring coils) the garage will probably push to change both left and right coils even if only one is buggered. This in general is good practice to keep load distribution even. I'd say the garage bill would probably be around the €200 mark (maybe a bit more)

keep us posted anyway

Edit: "spring coils" and "suspension springs" are the same thing. Those links I put up, that's what they are.

No problem. It sounds like it could well be the problem though
Thanks for the advice on changing both at same time

So you think if I check myself tonight, I will find it very hard to see if the rear coils are snapped i.e. it will probably mean taking it to a garage to actually find out if they are snapped in the first place

sebastianlieken

well you could choose if you wanted both replaced, I'd leave it to the mechanics judgment to be honest.

Yeah it'll be difficult to see if the rear ones are gone. You could just open the boot of the car, jump in, and have a good auld bouce up and down to see if you can hear the noise coming specifically from that region (get someone else to listen?). Mind you; your neighbours will think you've gone a bit mad.

Do check the front ones by hand though just to rule them out.

from_atozinc

for the rear one, if I took off the rear wheel, would it be easier to see if the spring is damaged or is this any advantage at all ?

sebastianlieken

from_atozinc wrote: »

for the rear one, if I took off the rear wheel, would it be easier to see if the spring is damaged or is this any advantage at all ?

No idea on a 3-series to be honest. But sure there's no harm in jacking it up and having a curious look!

from_atozinc

So had a look at the coil springs on all 4 wheels after work and could not see anything obvious.

Its Kinda hard to see and feel around the whole lot of them so kinda tricky.

I did another video of me rushing around checking the springs - back right, front right, front left, back left.

http://youtu.be/1Bqrmi9KfWg

The back right at the start of the video is the one I think is suspect but it seems to be ok from my initial check.