Low pitch squeak over bumps

[MakaveliX]

trevalvole said:

When I had a Mazda2, there was a noise from the rear of the car - it was the folding rear seat back that wasn't secured properly. Folding it and then firmly moving it back into place fixed it. Have you checked things like that?

Yeah checked everything. On the Mazda forum there's another member with the same noise who is trying to get to the bottom of it.

Sometimes sounds like someone thumping the rear of the car once over slow speed humps.

I personally think it is the shock absorber itself as the coil spring, drop link, anti-rollbar etc all look perfectly fine.

Bounce test on the corner of the car, it doesn't bounce excessively and there is no obvious signs of damage to anything.

Seems more noticeable the colder the weather. When warm it is not as bad

Edited by MakaveliX on Thursday 19th January 19:10

[MakaveliX]

Possibly a control arm at the rear ? Sometimes sounds like a popping noise

[Scotter]

MakaveliX said:

Possibly a control arm at the rear ? Sometimes sounds like a popping noise

Interesting to stumble upon this thread.
My previous two mazda MX5 NCs had what appears to be the same thing happen to them in colder weather when going over speed bumps approaching work.Above 6C the noise didn’t occur.
I ended up just accepting it as a trait of the cars.

[vw_99]

Not 100% on year. Bit if same as mk2 focus rear top mounts, they crack and give a noise before they break fully. Then u have a knocking when shock is moving about.

[MakaveliX]

Thoroughly checked everything all looks fine, lubricated all suspension bushes...

I think it may be the shock absorber itself however there is no evidence of anything wrong with it. Car doesn't keep bouncing when pressing down on the corner of the car and I only hear noise when going over bumps. It sounds like something in the boot is moving around.
Really odd.

Not willing to spend money on replacing parts unless I can pin point the cause of it.

[MakaveliX]

Only thing left then is rear top mount. Before getting it replaced is there any way to check if its going bad ? Don't want to be throwing money away replacing something which isn't worn.

I'm willing to inspect it from the outside but not remove the mount/shock absorber

[MakaveliX]

I had narrowed it down to it being the top mount at the rear.
On inspection it looks as if on one side of the car the top mount has been changed because passenger side has long bolts ( presumably OEM going by YouTube videos ) and the other ( driver ) has shorter ones.

Question is, is it possible to actually change these bolts ?? as I can't see any info on that. Photo is off YouTube but identical to one side of my car.


Thanks

[trevalvole]

I doubt it would make any difference changing the bolts themselves (unless they are the wrong width, or the head isn't big enough) - more likely it is some issue with the rubber in the top mount, or the lack of washers etc.

[MakaveliX]

trevalvole said:

I doubt it would make any difference changing the bolts themselves (unless they are the wrong width, or the head isn't big enough) - more likely it is some issue with the rubber in the top mount, or the lack of washers etc.

Thanks for the reply.
Yeah I gathered its most likely the rubber causing the noise.

What I'm really confused is why one of the previous owners had the bolts changed on the driver side, as the passenger side are OEM longer bolts. Usually if a top mount is bad then the mount itself is changed not the bolts.
Driver side is smaller and looks shiny and new, passenger side looks older and rustler and is long.

Upon some research them bolts are in an obscure place and are welded into place. On the Mazda 3 anyway, I know some cars are easily accessible in the boot

Edited by MakaveliX on Thursday 9th February 10:44

[Spydaman]

Had a similar squeek in an old Galaxy that sounded like a little cheepy bird in the back. Turned out it was from the spare wheel rubbing against the floor. The tyre had gone flat and the cable securing it to the underside was no longer tight. Cheep cheep cheep!

[MakaveliX]

Off the internet, here is a photo of where the top mount bolts are, they are welded on. I want to know why one of the previous owners had them changed ? maybe a collision of some sort ? It is not the kind of thing which would ever be replaced from what I've read

Circled in red is where they are. It cannot have been done by Mazda as the OEM bolts are much longer.

[MakaveliX]

Still a minor clunk in the back especially when cold.
Had me top mounts replaced today with decent aftermarket ones, still making noises

[MakaveliX]

Wonder if it could be the upper control arm bushings ? Whatever it is must be close to the boot as it literally sounds like something in the boot moving around.

Can't be anything serious as the temperature seems to affect it, on warmer days there is sometimes no noises at all.

Thing is, I don't want to go replacing all my suspension components to chase an annoying noise that may not even be coming from the suspension itself.

Edited by MakaveliX on Monday 6th March 19:10

[MakaveliX]

Still cannot locate this annoying noise.
The only days I don't hear it is when it's been warm for a couple of days.

It's a one off noise over speed bumps at low speeds which sounds like the word "pum" in a high pitch. Coming from the rear of the car around the boot area.

Can't see movement in anything and I've tried lubricating every suspension bushing at the rear of the car. Mechanic had a look too a while back and found nothing.

[MustangGT]

Try going over the speed bumps with the boot open. Could be the boot-lid moving in the catches.

[aterribleusername]

Spydaman said:

Had a similar squeek in an old Galaxy that sounded like a little cheepy bird in the back. Turned out it was from the spare wheel rubbing against the floor. The tyre had gone flat and the cable securing it to the underside was no longer tight. Cheep cheep cheep!

Had the same thing and the same reason in a Fiesta, except it was the rim edge now hitting the boot floor as the tyre was no longer holding it tight against the hand screw. Solved it with a bit of foam between the tyre and the boot floor and also checking the spare's pressure more often!

[MakaveliX]

MustangGT said:

Try going over the speed bumps with the boot open. Could be the boot-lid moving in the catches.

Yeah I did consider this. If I push the boot lid around when it's closed there is no movement or noises.
I did get some anti-rattle tape on the rubbery catches but no luck.

the only clue I have is that it is definitely more prevalent when the weather is cold. Above 12c it is pretty much silent. Surely that would indicate a rubber mount or bushing of some sort ?

[E-bmw]

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]

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.

Thanks for the helpful post.

I think you are right, the only thing it could be now is the shock absorber itself, as everything else looks fine... Not sure why it only does it on the rear passenger though, and another forum member posted above they had the same thing in both of their MX5s ( coincidence or not ? )
Also searching the Mazda forums, " suspension clunks " seem very common and most people had no success sorting it out

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.

For now I'll have to live with it as we are coming into summer soon and the sound should be much less prevalent in the warmer weather - then worry about it next winter.

In terms of the shock, from the outside anyway, looks in good condition, no leakage etc and if I bounce on the corner of the car it doesn't keep bouncing and seems very firm and healthy. No noises there either.

I am qualified to replace struts but I don't want to be taking my daily driver apart in a car park ( as I don't have a garage )

Other thing is the Mazda 3 Gen 3 has so much plastic underneath it is very difficult to find anywhere to put an axel stand ( my mechanic also agrees ) so I will have to leave it alone I think.

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.

In regards to when it started ( or at least when i first noticed it ) , it was when the weather was really icey cold and had to get the de-icer out. On my way home hit one of them nasty 5mph speed bumps a bit too quick.

Edit: what I'll do at some point is get my mechanic to rotate the rear shock absorbers and see if the noise persists

Edited by MakaveliX on Wednesday 15th March 08:38

Edited by MakaveliX on Wednesday 15th March 09:50

[MakaveliX]

Seriously annoying. Noise disappeared for about 5 days then came back again yesterday.