- My model of MX-5 is: ‘07 NC 1.8
- I’m based near: Oxford
- I’m looking for technical help or recommendations on: mysterious rattle
Just got back from my decent local garage; took my MX5 to deal with a strange rattle but they couldn’t find any issues. Adds up, because I’ve struggled to find anything. So, I’m here looking for some thoughts from the experts 
Since around February my NC has had a very loud rattle specifically at very low speeds, generally 20mph and less. It sounds like it’s coming from the right rear, but not totally obvious. It has a ‘metal on metal’ quality, I think, but could also be metal on tough plastic. Once I speed up it completely disappears - and not in a ‘I can’t hear it any more’ way, it just seems to smooth out to the point where it doesn’t have the problem.
Naturally it seems like a suspension issue but the garage couldn’t find anything wrong. And given I’ve had this problem since February with no clear major issue with the car, it doesn’t seem to be anything critical. So that’s good. But I’d sure like to get rid of this darn noise!
Any ideas/thoughts would be much appreciated!
Worth noting, it seemed to start not long after I had new front brake callipers, discs, pads + one front drop link replaced. But doesn’t seem to be related… I think.
Rattles are often drop links though a competent garage should be able to identify that
Is it a dull knock rattle or a buzzy resonant ratlle?
I know this may be a stupid suggestion but is your jack secure and and any tools in the right hand boot compartment?
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I agree with your tool suggestion.
I was in Norfolk this week and had a metal on metal sound from right hand boot area.
After stopping, the issues were the towing eyes and jack handle in the boot compartment.
A quick adjustment and it was sorted 
Good questions! It’s a dull knock.
And can confirm it’s not the Jack/tools. I’ve checked that in the past but I even took them out during the drive back from the garage just to double check - still there!
Just helped a mate fix a knock/rattle on his NC
We had already done front and rear drop links and had all the bushes closely inspected by the local MOT guy.
Ended up being pad knock.
Once we changed his pads to Mintex - the knock vanished.
He managed to stop the knock/rattle temporarily by very lightly touching the brake without slowing the car down.
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Now that’s an interesting theory. Given it started after the brakes were changed.
Will give that a shot tomorrow!
Sorry to drag up an old thread but did you ever get to the bottom of your rattle? I’ve developed what sounds like the same issue with my NC.
I’ve taken everything out of the boot, the sound seems to disappear when traveling faster (driving down side streets is worst).
Had the car MOT’d last week with no issues. I appreciate it’s not a thorough examination but when I asked the guy said everything seemed in good order??
Hey!
So - my initial issue went away very recently when I replaced the anti-roll bars. So it seems very likely it was a drop link issue, or rather one wasn’t installed quite right. Maybe worth replacing in your case, or at least re-installing the current ones.
Funnily enough, my car developed a new rattle over the weekend that sounds more like a damn rattlesnake at low speeds. I have a sneaky feeling I’ve got some stones in my cobalt exhaust though, so will try to fish those out soon. Hope it’s just that.
This might be a long shot but it could be the battery clamp? I recently had to bodge my clamp to stop it bouncing around, as it’s not the right size for the aftermarket battery
It had new drop links on the front when I renewed the brake shields/hubs there. If I remember the rear drop links were advised on its last MOT with me, they were replaced too. So it should be ok there, how long those last who knows??
Cheers for the replies.
I had a look underneath the other day, everything seemed in pretty good condition. I stripped out the entire boot lining and removed the travel sweets but the rattle is still there?
I looked through the receipts you gave me Mike and noticed that the drop links were changed not long ago so I’d discounted them but as I’ve drawn a blank I think I’ll replace them just in case (they’re pretty cheap and easy to sort by the looks of things).
If that doesn’t solve the problem I’ll expand my search…
I had a rattle at low speeds on my previous 07 plate NC sport, just on those rippled road surfaces. On speed bumps or more severe ruts in the road that sometimes you can’t avoid it didn’t make a rattling noise.
I checked everything possible at the time, even new drop links, it still persisted. It wasn’t a problem as it was just intermittent but very noticeable on road surfaces mentioned above.
I wanted a complete change of suspension and lowering at the same time so had MeisterR suspension fitted and alignment. The rattle completely disappeared, no more annoying noises over those rippled roads.
There has been discussions about Bilsteins rattling, the collars or bushes at the top of the units, I do believe this was my problem as it had Bilsteins on coupled with lowering springs.
Mike as you probably know yours has MeisterR Sportives on so I would probably discount those as a problem, probably nothing broken there as it’s just had the MOT.