Suspension Knock at slow speeds/turning

[Joel]

Hi all,

So I've got a bit of a problem that no matter how much I drive it won't go away ( )
My MX5 seems to have a small suspension knock on the passengers side (as far as I can tell). I noticed it after thrashing the car down some fairly rough roads and perhaps has gotten progressively worse over time, the sound volume of the knock is the same but it knocks more frequently particularly when slow turning at half to full lock. It will also make itself known sometimes on lightly uneven roads if I'm going any less than 15 kmph.

My coilovers are around 9-10 months old and don't appear to be leaking, damping adjustments still appear to be working and changing the struts accordingly (not sure if that would be affected anyway though). My passenger chassis rail is damaged as if a jackstand was placed there to hold the car but that has been there since before i bought the car a year ago, there's no play in the wheels/hubs and ball joints FEEL fine.

Anyone have any other ideas at what it could be?

[SkilletKid]

Check suspension bushings if they look like they've been "squeezed" out. Check ARB (swaybar) endlinks (the bolts and their bushings).

Put it on stands and try wiggle the wheels about (checking for play in the hubs/bearings).

Whilst on the stands, put a jack with a large enough sheet of plywood or a metal plate under the wheels and try get it to move through it's range of motion (maybe have someone sitting in the car moving the steering at the same time) and check for the noise.

Check wheel nuts?

[Angreal]

My fm rear sway bar makes a clunking noise at low speeds as it slips around a tiny bit. I think fm changed the design slightly to fix this in their newer ones

[SkilletKid]

Oh forgot to mention; check the ball joints/steering rack ends.

Check the rack whilst you're down there. Is it only during turns? (You mention the lightly uneven roads but are you turning or going straight?)

How damaged is the chassis rail? Just bent up and ugly or ripped and needs some welding? Any other underbody damage?

[PLSEME]

Had the same issue on my car .......
After changing Sway bar link end
checking the brakes
Full Bush kit replacment

turned out to be the top strut mounts

[Joel]

Check suspension bushings if they look like they've been "squeezed" out. Check ARB (swaybar) endlinks (the bolts and their bushings).

the swaybar endlinks appear to be alright, other bushing have yet to be checked though, could be that.

Put it on stands and try wiggle the wheels about (checking for play in the hubs/bearings).

There's no play there

Whilst on the stands, put a jack with a large enough sheet of plywood or a metal plate under the wheels and try get it to move through it's range of motion (maybe have someone sitting in the car moving the steering at the same time) and check for the noise.

The car has to be moving for any of the knocking noise to be made

Check wheel nuts?

Not the wheel nuts, all are tight.

My fm rear sway bar makes a clunking noise at low speeds as it slips around a tiny bit. I think fm changed the design slightly to fix this in their newer ones

The noise sounds like the front suspension

Check the rack whilst you're down there. Is it only during turns? (You mention the lightly uneven roads but are you turning or going straight?)

How damaged is the chassis rail? Just bent up and ugly or ripped and needs some welding? Any other underbody damage?

Turning or straight road it makes the same knocking noise :/

it's bent upwards and may be touching the passenger floorpan as I have been told you can feel the knock with your feet.

Had the same issue on my car .......
After changing Sway bar link end
checking the brakes
Full Bush kit replacment

turned out to be the top strut mounts

Was it an easy fit or was the solution new struts?

[PLSEME]

You do need to pull the struts out ....(not a hard job) but it dose take time.
got the replacment top strut mounts from "The Mount Shop" in Penrose.

[Joel]

Front struts are a bastard, will throw in my old factory suspension sometime to find if I find it isn't a problem with the bushings to see if the knocking persists. Thanks!

[marcellarius]

Lol, I was helping a friend diagnose a loud knock last week... it sounded steering related and we spent a while checking tie rods, steering rack etc. We gave up on that and went to collect more evidence (i.e. drove in circles in empty car park) and discovered it only happened on left transitions. A CLUE. Upon looking at the anti-roll-bar the next day, I noticed a big stone sitting between the ARB and subframe, which must have been getting crushed as the ARB twisted.

[marcellarius]

This is a good video about looking for suspension noises https://www.youtube.com/watch?v=scFbb43fwqk

[SLYDIT]

knock knock...
Who's there?
Miata
Miata who?

Me ata here....weeeeeeeeeeeeeeeeee!