Z3 plastic(?) noises

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Inferno
Joined: Sun 30 Sep, 2012 07:35
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  Z3 roadster 1.8
Location: Athens

Z3 plastic(?) noises

Post by Inferno »

i have for the last 2 years a VERY disturbing noise each time i press AND lift the throttle, that means each time the chassis is moving "back" or "forth" (well i think it's more when the rear end moves up and down). I cannot understand if it's a noise from plastics rubbing each other or metals rubbing each other, i believe it's coming from the area behind the roll hoops, i have checked everything there it's all good, i checked the rear diff, it's ok, i checked the subframe it's ok, i removed as much as i could from the rear plastics as i could and reinstalled them but still no fix.

I have noticed that with the roof down i don't hear it at all, and i noticed that each time someone sits on the driver seat (that's me :P) i hear a similar noise from the left rear suspension, or handbrake drum...

any clues?
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BladeRunner919
Joined: Fri 17 Feb, 2012 20:18
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  Z3 roadster 1.9

Re: Z3 plastic(?) noises

Post by BladeRunner919 »

Could be the top shock mounts - they have a habit of being noisy/squeaky. Try spraying a bit of silicone lubricant into them to see if it quietens them down.
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

how can i have access to them? you mean the top of the suspension under the "carpet" behind the roll hoops?
stevie_a
Joined: Tue 13 Dec, 2011 23:18
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Location: Glasgow

Re: Z3 plastic(?) noises

Post by stevie_a »

Ok stop there!

Sounding very familiar, I have the same problem.

I have done this to rectify so far.

1. New rear shocks
2. New rear top mounts
3. New subframe bushes
4. New rear drop links
5. 4 new tyres ( Falken to limit tramlining )
Only thing I can change now is the rear diff mount and I will do this very soon.

I am now convinced it is this, and it is moving everything about.

When you drive down the road and go over uneven ground is the back end jump about (not a lot but just not as tight as it should be ?)
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

i don't think so, on the other hand i rarely drive the car, so i have not noticed something like that. it's a "weekend" car, i drive it maybe 1-2 times per week
stevie_a
Joined: Tue 13 Dec, 2011 23:18
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Location: Glasgow

Re: Z3 plastic(?) noises

Post by stevie_a »

Just with all the expenses I have been put through I will hate someone to go through The same without checking this part as you can buy a poly bush for under £40
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

i will definitely check it bro, next time i visit the garage!
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BladeRunner919
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  Z3 roadster 1.9

Re: Z3 plastic(?) noises

Post by BladeRunner919 »

Inferno wrote:how can i have access to them? you mean the top of the suspension under the "carpet" behind the roll hoops?
Yes. Definitely worth a squirt of lubricant before tearing the car apart!
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BladeRunner919
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  Z3 roadster 1.9

Re: Z3 plastic(?) noises

Post by BladeRunner919 »

stevie_a wrote: Only thing I can change now is the rear diff mount and I will do this very soon.

I am now convinced it is this, and it is moving everything about.
The diff is bolted directly to the subframe, as well as to the visible mount. There shouldn't be any real 'moving about' unless you have some serious problems (broken welds in boot, for example)
Last edited by BladeRunner919 on Thu 12 Feb, 2015 09:55, edited 1 time in total.
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

BladeRunner919 wrote:
Inferno wrote:how can i have access to them? you mean the top of the suspension under the "carpet" behind the roll hoops?
Yes. Definitely worth a squirt of lubricant before tearing the car apart!
I will try WD-40, should do the job i think
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

Unfortunately the noise continues, lubricate didn't helped at all...

It's REALLY annoying :head:
Del
Joined: Sat 19 Nov, 2011 18:35
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  Z3 roadster 1.9

Re: Z3 plastic(?) noises

Post by Del »

Based on my own experience the rear shock absorber top mounts squeak like "chipmunks", over every slight bump, when they are worn and need to be replaced. It is much louder with the rear carpet removed. With the carpet in place and roof folded down into its recess, it is not audible as all of that bulk is insulating the noise. Also in my experience worn drop-links make a more metallic "clinking" noise on hard cornering and more major road bumps - the roof being up or down makes no difference.
Clivebse
Joined: Sun 15 Sep, 2013 22:09
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Location: Suffolk

Re: Z3 plastic(?) noises

Post by Clivebse »

Try the petrol tank moving about. We had a customer whith what sounds like the same noise. Not a nice job so we re packed the straps around the tank with rubber hose. This was at the customers request.
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

The noise is clearly comes from the area behind the hoops, where the soft top folds, so it's more logical that it is the top mount(s). If that's the case someone has to kill me because i have this noise for like 2 years now, i could easily have an accident. i will check it asap garage is closed today
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

So, i checked the rear top mounts, the left seems ok but the right is damaged, i also recorded the noise i hear, tgis was produced when i was pushing the rear of the car down

Left:
Image

Right:
Image

Sound: https://www.dropbox.com/s/pcobeyvaq6bkk ... 1.m4a?dl=0
Del
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  Z3 roadster 1.9

Re: Z3 plastic(?) noises

Post by Del »

Recent Youtube video of tired rear Z3 shock absorbers being pulled up and down slowly during a renovation process. Given that you are bouncing yours up-and-down more quickly, the noise sounds broadly similar?

https://www.youtube.com/watch?v=eJv0fqu ... e=youtu.be
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Inferno
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Re: Z3 plastic(?) noises

Post by Inferno »

We found the problem, it's the diff bushing, at first we thought it may was the sub frame, but it's not an ///M, so... We lifted it and saw the destroyed bushing...
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Inferno
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  Z3 roadster 1.8
Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

diff bushing changed yesterday with a new original BMW, garage charged me 80€ for the change plus 40€ for the bushing, he told me that he couldn't change it without taking the diff off the car and put it on the bench, i wasn't present as usually so i cannot be sure, anyway, 95% of the noises are stopped, i still have sometimes the same noise but only when the car goes off from a full stop and not everytime, and not so loud as before, maybe it's the rear topmounts that i didn't changed yet, or the rear plastics of the cabin...
Del
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  Z3 roadster 1.9

Re: Z3 plastic(?) noises

Post by Del »

Because Z3s are quite old cars now, most would benefit from changing all original bushes and suspension parts underneath the car, so I wouldn't view the renewal of the diff. bush as a waste of money even if it didn't 100% cure the problem. It was still good preventative maintenance.
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Inferno
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Re: Z3 plastic(?) noises

Post by Inferno »

Del wrote:Because Z3s are quite old cars now, most would benefit from changing all original bushes and suspension parts underneath the car, so I wouldn't view the renewal of the diff. bush as a waste of money even if it didn't 100% cure the problem. It was still good preventative maintenance.
i agree, bushings are a big part of how a car feels, especially in so old cars! It's just, i don't know if i paid too much for the change, or it was a typical price
Del
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Re: Z3 plastic(?) noises

Post by Del »

Your labour charge (E80) looks low by UK standards bearing in mind you used an OE type bush that needed to be pressed back in. When I changed mine we just lowered the exhaust and diff (diff supported on trolley jack) as we were just cutting out the original and replacing with a Powerflex one which can simply be slid in by hand. Powerflex bushes seem to be designed for ease of fit for DIYers
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Inferno
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Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

Del wrote:Your labour charge (E80) looks low by UK standards bearing in mind you used an OE type bush that needed to be pressed back in. When I changed mine we just lowered the exhaust and diff (diff supported on trolley jack) as we were just cutting out the original and replacing with a Powerflex one which can simply be slid in by hand. Powerflex bushes seem to be designed for ease of fit for DIYers
That's exactly what he told me, he had to press the bushing to the diff, i proposed him to install a powerflex instead (without knowing at that point that the powerflex can be installed without taking the diff off the car), but he advised not to install a hard bushing like powerflex in an old car like this so we installed the oem instead
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Southernboy
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Re: Z3 plastic(?) noises

Post by Southernboy »

If the noise is apparent when pulling away it is most likely the rear top mounts. As the rear of the car drops on pull away, those bushes have the pressure released from them somewhat, so any considerable wear will allow them to "rattle" and "creak"... If you're replacing one you need to replace both. Meyle make excellent quality top bushes and at considerably less cost than the OEM from BMW.
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Inferno
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Re: Z3 plastic(?) noises

Post by Inferno »

Southernboy wrote:If the noise is apparent when pulling away it is most likely the rear top mounts. As the rear of the car drops on pull away, those bushes have the pressure released from them somewhat, so any considerable wear will allow them to "rattle" and "creak"... If you're replacing one you need to replace both. Meyle make excellent quality top bushes and at considerably less cost than the OEM from BMW.
I will replace both of them, and yes i was too thinking about putting Meyle on :)
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g8jka
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Re: Z3 plastic(?) noises

Post by g8jka »

I am now experiencing some creaking noises from the rear of my car, at first I thought it was the hardtop but it sounds like the top mounts although I fitted brand new ones last month. Its at low speeds when I'm slowing down or pulling off and all points towards top mounts but seems strange that brand new ones would be noisy?
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Del
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  Z3 roadster 1.9

Re: Z3 plastic(?) noises

Post by Del »

Fitted these on my Z3 three years ago - been fine since.

http://www.ebay.co.uk/itm/BMW-3-SERIES- ... 2a15ec4d64
gookah
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Re: Z3 plastic(?) noises

Post by gookah »

g8jka wrote:I am now experiencing some creaking noises from the rear of my car, at first I thought it was the hardtop but it sounds like the top mounts although I fitted brand new ones last month. Its at low speeds when I'm slowing down or pulling off and all points towards top mounts but seems strange that brand new ones would be noisy?
Yours are Meyle as well
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Southernboy
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Re: Z3 plastic(?) noises

Post by Southernboy »

If you have new top mounts that are creaking, a little rubber grease will sort it out - make sure it's rubber grease though, some greases have petrochemicals in them which isn't good to use.
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Inferno
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Location: Athens

Re: Z3 plastic(?) noises

Post by Inferno »

i ordered a pair of Meyle HD from UK for £21.5, really good price i hope that will solve the problem because car now started doing the same noise as before the rear diff bushing replacement
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