Low pitch squeak over bumps

[E-bmw]

MakaveliX said:

E-bmw said:

The one thing that is hard to replicate/diagnose & looks increasingly likely with what you have done to date is the actual shock itself.

When the weather is colder the oil in the shock is thicker, perhaps this is the defining factor?

If it sounds like it is one specific side, could you swap them over?

The only way I can think of to replicate the issue is as follows.

Jack the rear of the car up & sit it on stands supporting the body so that the suspension can still move freely.

Jack the suspension up on a trolley jack & release it at a controlled rate & see if you can hear the noise return.

You may have to try faster/slower to see if you can get it to happen.

MakaveliX said:

It's strange because it sounds like the noise is in the boot even though I have tried taking everything out the boot and it persists.

It will, as the boot is where the top end of the shock is connected.

MakaveliX said:

I have looked on YouTube at what a bad shock sounds like, again, its completely different to what I experience. Bad struts tend to sound more rattly, whereas in my car it's a one off rubbery clunk sort of noise.

But as I said, it isn't necessarily a bad shock, it sounds like it is a breakdown of the oil in the shock.

[MakaveliX]

E-bmw said:

But as I said, it isn't necessarily a bad shock, it sounds like it is a breakdown of the oil in the shock.

Yeah thanks for the useful information, appreciate it

Considering the noise did start after hitting a nasty 5mph bump too fast.
And bearing in mind that the drop links, anti-rollbar, and my control arms have no movement in them, plus I have greased all of the bushings and ball joints with no luck. AND a qualified mechanic has checked all of this.

And the fact it sounds like its around the boot area ( as you say, this is where the shock connects to the car via the top mount ( which has been replaced a month or so back ) it most likely is the shock then.

The other thing is. If I hit a bump with the front of the car, I sometimes then hear the noise at the back of the car simultaneously ( I'd assume this is because the car squats down when the front hits it and the shock will be dampening that )

What I'll do is see if it improves much when the weather gets more consistent ( unlikely as since when it started i've pretty much heard the noise every single day over certain bumps ) I'll get myself some decent aftermarket shocks for the rear ( good thing is it's independent rear suspension meaning its a quick job for a mechanic as it does not involve a coil spring )

Sometimes it's more a thump noise than a clunk, but i'd assume shocks can cause this.

The two I have narrowed down are Monroe or KYB.. both of which are supposed to be firm, more so KYB ( which I like ) and allow the car to sit a little bit lower ( again, not fussed about this ) I am siding with KYB as I heard monroe can be bouncy which I do not like
Any suggestions are welcome.

Thanks

Edited by MakaveliX on Thursday 23 March 15:50

[cuprabob]

MakaveliX said:

The two I have narrowed down are Monroe or KYB.. both of which are supposed to be firm, more so KYB ( which I like ) and allow the car to sit a little bit lower ( again, not fussed about this ) I am siding with KYB as I heard monroe can be bouncy which I do not like
Any suggestions are welcome.

Thanks

Edited by MakaveliX on Thursday 23 March 15:50

The spring dictates the ride height, not the shock absorbers. With the same spring both the KYB and Monroe will have the same ride height.

[MakaveliX]

cuprabob said:

The spring dictates the ride height, not the shock absorbers. With the same spring both the KYB and Monroe will have the same ride height.

Yeah good point. On me old car I had the springs replaced with cheapo ones ( due to an advisory at the MOT ) and the car looked like it was on stilts and looked dreadful

Seriously though I'll go for the KYBs then as from what I've heard you get a nice stiff and stable ride around corners.

I'd fit them myself but I don't have a garage to work in unfortunately, neither do i have a 2 or 4 post lift.. Will get my friendly mechanic instead then.

Edited by MakaveliX on Thursday 23 March 16:17

[E-bmw]

MakaveliX said:

E-bmw said:

But as I said, it isn't necessarily a bad shock, it sounds like it is a breakdown of the oil in the shock.

Yeah thanks for the useful information, appreciate it

MakaveliX said:

The other thing is. If I hit a bump with the front of the car, I sometimes then hear the noise at the back of the car simultaneously ( I'd assume this is because the car squats down when the front hits it and the shock will be dampening that )

Correct, the whole car will rotate about the centre of gravity when hitting a bump.

MakaveliX said:

Sometimes it's more a thump noise than a clunk, but i'd assume shocks can cause this.

Yes, the issue will be internal to the shock & so can likely sound different in different circumstances.

MakaveliX said:

The two I have narrowed down are Monroe or KYB.. both of which are supposed to be firm, more so KYB ( which I like ) and allow the car to sit a little bit lower ( again, not fussed about this ) I am siding with KYB as I heard monroe can be bouncy which I do not like.

Monroe shocks shouldn't be bouncy unless they aren't working, they are designed to remove the tendency to bounce, that is how they work.

Having said that I have used KYB on Mrs E's previous Mazda 2 & my previous V50, they have been in the suspension game for many years.

[MakaveliX]

Brilliant thanks guys.

I'll most likely get the KYBs then, after some reading they are one of the best brands out there.

By bouncy I meant that the Monroes aparrently give a softer ride. However I don't know how much you'd notice this if it's just the rears being replaced.

Another question is it is OK to just get the rears done right?, I don't want to replace the front ones as they are fine.
Stock Mazda's could potentially be KYBs anyway.

[cuprabob]

MakaveliX said:

Another question is it is OK to just get the rears done right?

Yes.

[E-bmw]

cuprabob said:

MakaveliX said:

Another question is it is OK to just get the rears done right?

Yes.

^^^^ Wot 'e said.

[MakaveliX]

Thanks for the info guys I'll get them KYB's as soon as I can.

Not sure why new shock absorbers don't come with new dust boots ( if that's the correct term ) Tried sourcing some out of interest for my car and they seem non existent on the internet.

Before I order. I'd assume it's not a control arm potentially causing it ? From my knowledge a bad control arm would have movement and would rattle over bumpy roads however there is no rattle at all , just the one off clunk over speed bumps, when the weather is warmer it tends to be more of a "thump".
Also I have lubricated every control arm bushing with no luck. On both sides of the rear of my car I have the upper control arm ( wishbone style ), trailing arm in the middle, then a lower control arm too.
I'd assume my mechanic checked this as they're pretty good.

The only thing close to the noise is this video off YouTube of a bad shock https://youtube.com/shorts/ULvanzHXFEk

So I'm hoping that's what it is.

Edited by MakaveliX on Sunday 26th March 17:10

[E-bmw]

MakaveliX said:

Not sure why new shock absorbers don't come with new dust boots ( if that's the correct term ) Tried sourcing some out of interest for my car and they seem non existent on the internet.

They rarely come included, even when ordered from Main Dealers. however they are a pretty generic item, I would suggest a quick measure of the fitted ones & a generic search on ebay will find some for peanuts.

MakaveliX said:

Before I order. I'd assume it's not a control arm potentially causing it ? From my knowledge a bad control arm would have movement and would rattle over bumpy roads however there is no rattle at all , just the one off clunk over speed bumps, when the weather is warmer it tends to be more of a "thump".
Also I have lubricated every control arm bushing with no luck. On both sides of the rear of my car I have the upper control arm ( wishbone style ), trailing arm in the middle, then a lower control arm too.
I'd assume my mechanic checked this as they're pretty good.

As per previous conversations, yes it COULD be, but I was under the impression that these had been ruled out.

To finally rule the shock in/out, do what I said & swap them over, if the noise moves you have the culprit.

[MakaveliX]

Found an interesting TSB which describes it to a tee ( yes it's Toyota but it sounds the same issue )
https://static.nhtsa.gov/odi/tsbs/2020/MC-10181779...

KYB shocks are here. I'll monitor the noise over the next few week, if it subsides with the warm weather which is likely, I may leave it until the winter to get them fitted.

Regarding the dust boots, I cannot find any anywhere but I'll ask my mechanic when I get the shocks fitted

[E-bmw]

MakaveliX said:

Regarding the dust boots, I cannot find any anywhere but I'll ask my mechanic when I get the shocks fitted

A very quick search on ebay reveals 1700+ not sure why you aren't finding any.

https://www.ebay.co.uk/sch/i.html?_from=R40&_t...

[MakaveliX]

Got the shocks fitted today, noise still there albeit it a bit quieter

Gonna have to give up

Upon inspection, one of the old shocks was bad compared to the other old one so at least that's something. If I compress them both ( the old shocks ) at the same time they return at different rates.

Rather than a squeak, it's more of a knocking noise when it's warmer.

I still cannot figure out whether it's even coming from the suspension as the noise is not muffled and sounds like something around the boot area. I have checked the boot lid etc and it seems OK

As my car has three different control arms on either side of the rear axle it would be extortionate to continue replacing parts in the hope it fixes it.

Another observation is that one of the shocks is definitely newer than the other, which means that one of the previous owners has replaced one of them and at less than 20,000 miles is slightly odd. So maybe there was some impact to the car at some point

Edited by MakaveliX on Wednesday 5th April 17:30

[MakaveliX]

Any ideas guys as I'm at a dead end.
Changed the shocks and changed the top mounts but still it persists. Lubricated every bushing and mount under the car.

With the warm weather its much much quieter, then in the mornings when it's cold its much worse

Fairly sure the drop link is fine, if I hit it there is no noise and no movement at all... my mechanic said they are fine too.

Can bad drop links make noises over even speed bumps ? I thought they only come into play over uneven Road surfaces and really windy roads at speed

Edited by MakaveliX on Saturday 8th April 16:18

[MakaveliX]

When the noise disappeared for 4-5 days. and then came back - The only thing that had changed is it had rained heavily. So maybe there is some ingress getting into the links or something ?

[E-bmw]

Well, kt can only be coming from something that moves with the suspension travel, not too many things to check, but they clearly all need checking properly rather than assuming they are good because they don't look worn.

[MakaveliX]

E-bmw said:

Well, kt can only be coming from something that moves with the suspension travel, not too many things to check, but they clearly all need checking properly rather than assuming they are good because they don't look worn.

Mechanic did check it, and they are decent down there.

I'll get a pry bar and check myself then. Is a 60CM one good enough ?

Going up level speed bumps as far as I know used the shocks and springs mainly. And they are definitely fine because the shocks are brand new, so are the top mounts.
That would leave suspension arms right ?

Still begs the question as to why the temperature plays a big impact in it.

Edited by MakaveliX on Sunday 9th April 19:31

[E-bmw]

MakaveliX said:

E-bmw said:

Well, kt can only be coming from something that moves with the suspension travel, not too many things to check, but they clearly all need checking properly rather than assuming they are good because they don't look worn.

Mechanic did check it, and they are decent down there.

I'll get a pry bar and check myself then. Is a 60CM one good enough ?

Still begs the question as to why the temperature plays a big impact in it.

I have i=one I use that will be more like 90cm, but you can only use what you have.

You can also get a helper to try to rock the body on the suspension whilst the car has weight on the wheels, as don't forget, you ideally need the car sat on its wheels with you underneath.

WRT temperature, if it happens when cold perhaps a rubber bush is just loose enough to twist/squeak when contracted a little due to cold.

[MakaveliX]

E-bmw said:

I have i=one I use that will be more like 90cm, but you can only use what you have.

You can also get a helper to try to rock the body on the suspension whilst the car has weight on the wheels, as don't forget, you ideally need the car sat on its wheels with you underneath.

WRT temperature, if it happens when cold perhaps a rubber bush is just loose enough to twist/squeak when contracted a little due to cold.

Thanks appreciate the information. It's likely I'll have to just live with it as suspension noises are apparently common in these cars and it's just down to the design ( after asking some mazda owners )

When I get my pry bar underneath and wiggle some parts around, is it likely I'd hear a noise whilst prying the culprit ? Also, I'm looking for any excess play right ?

It's an odd one because sometimes the noise sounds high up, much higher than where the suspension components are. I mean like the top of the boot lid on the passenger side.

Could even be the exhaust moving about a bit, I have checked the mounts and they seem fine.

I'll get prying and see what I can find

Assume it's not the drop link or anti rollbar as i went on a long quiet road and did some vigorous steering left and right with no noises at all, just speed bumps.

Edited by MakaveliX on Monday 10th April 10:27

[E-bmw]

I don't think you are going to detect play as that is what your mechanic will have been looking for.

You are just looking to recreate the noise to find where it is coming from as I don't think you will see anything.

As I said you need the suspension to be loaded while you are under there to recreate the scenario you describe.

Ideally, you also need the handbrake off.

This is going to be quite difficult to do safely, so you need to make sure the car is going nowhere.

Ideally a set of 4 ramps to drop the car onto facing away from each other so that the car can't roll.

You may then also need to jack the individual wheel/suspension up/down to simulate the on-the-road scenario, it really isn't going to be easy, but above all, make sure the car is 100% safe to go under.

4 of these would do it.