Mk3.5 Loud Dashboard Rattle

Hi, my MX-5’s suddenly developed a really annoying, loud interior rattle today.

This started immediately after I had to brake fairly hard to avoid somebody who pulled out on me.  Since then, there’s been an almost constant loud rattle from the driver’s side of the dashboard - seems to be coming from inside the area at the top of the dash to the right of the instruments I think?

I’ve had the instrument cowl off & the rattle’s still there (it’s not the Bluetooth Microphone either); I also tried it without the column cowl, also with the instrumentation unscrewed (but not disconnected) - originally I thought it was coming from the instrumentation but now seems more likely that it’s rattling from somewhere behind the dash itself.

I’ve had a good poke around under the dash & can’t find anything loose, the ducting to the demister vent’s properly seated etc.

There seems to be no way to get at the very top of the dash, where the sun sensor’s located for the Climate Control - I was wondering whether it might be something to do with that?

The rattle sounds like a loose piece of plastic rattling around, it’s most noticeable at slower speeds (eg around town) when it rattles constantly; on the motorway it doesn’t rattle much at all.  It’s definitely a rattle type noise, not a buzz.

It even rattles - one “tap” type noise - sometimes when I engage first gear with the car stationary - something’s obviously very loose & it’s definitely something related to the dashboard / interior.

It’s really loud & already driving me mad - does anybody have any ideas please?


If its a PRHT Is it definitely not the roof ?

Thanks pfw - yes, it’s a PRHT, however the rattle’s there regardless of whether the roof’s up or down - the roof was down when it started - so it definitely isn’t the roof panel.

I have seen a thread on another forum about loose torx bolts inside the header rail trim causing a rattle which sounds as if it’s coming from the instrumentation area, I’ve just removed the header rail trim & checked - all bolts were present & tight, which unfortunately (for me) rules that out too.  Nothing untoward inside the “A Panel” trim at the side of the windscreen either.

It’s a really loud & very annoying rattle, definitely something inside the dash / instrumentation area at the driver’s side & so loud that it’s ruining the car at the moment to be honest - I wondered whether I’d dropped something into one of the air vents but I haven’t had anything on the dash at all which could have found its way in there.


Hmm, has the radio been out? Was the ‘impossible to find’ security bolt lost in the depths, but now resurfaced elsewhere as a result of the heavy braking?

Or, much worse, has something broken loose in the pedal assembly?

Thanks Richard - the radio’s never been out.

I did check the pedal assembly when I was looking at it yesterday, but I’ll double-check that; there’s no untoward behaviour with the controls / instrumentation - it’s very odd, a little worrying & very annoying!




Have you had someone in the passenger seat try and locate the noise while you drive? I ask as these rattles and knocks can be very elusive and may sound as though they are coming from somewhere else from the passenger seat. I had a noise coming from the roof of my PRHT and I was convinced it was coming from behind my right ear but in fact it was coming from the lugs above the windscreen.
Just a thought.

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After about 3 months, the very annoying rattle which sounded like it was coming from the glove box, turned out to be the rear view mirror.

I was struggling to source the location in my daily, turned out to be my sunglasses in the storage space.

But back to the MX5.


Isn’t there a few relays under the dash, just above the bonnet pull ?, or did I dream this ?

Thank you all for your helpful suggestions re. this - greatly appreciated.

The good news is that I think it’s fixed!

Just before the journey when it started, I’d put some eye drops in (I have a chronic dry eye problem) using the vanity mirror inside the driver’s sunvisor.  On the back of the hinged mirror cover is a credit card holder where the Mazda Assist card (now over 4 years past its expiry date) has always lived since the car was new.

When I started to take out the header rail trim yesterday evening, the plastic Mazda Assist card fell on to my lap.  I didn’t think anything more of that at the time & didn’t test drive the car straight after putting the header rail trim back together, because I’d found nothing amiss.

Then late last night, clutching at straws a bit, it struck me that the plastic card could, just possibly, be the source of the noise?  Maybe having come loose when I’d used the mirror & then jolted free when I had to brake quite sharply?

I removed the Mazda Assist card this morning, took the car out - & the rattle’s completely vanished.  So,hopefully, that’s that! 

As other posters have said, sometimes a rattle isn’t coming from the area from which it appears to be - as has been evidenced on this occasion!

Tried posting this morning but kept getting the 404 error code 

Andy, I didn’t post anything up previously as I didn’t feel I could offer any assistance, anyway, got up this morning and thought

I wonder if there’s an out of date Mazda assist card kicking about anywhere?”

i was going to suggest this and blimey, you’d already got it sorted! 


So it didn’t assist you in any way??

Glad it’s sorted and simple.

Thanks - nice one Barrie! 

I’ve been having problems with the 404 error code too.


Thanks Mick! 


I’m glad you got it fixed. My car had 3 rattles when I first got it (2 previous owners). I totally agree that a passenger needs to be present to locate it. I was certain that a noise was coming from inside the dash around the radio. It turned out to be the roof lock. I’ve got another that I’m sure comes from around the dials, but the sound isn’t present with the roof down. I now think it could be from where the roof connects to the top of the windscreen. 

I know this is an old post… but

I had what I thought was a dashboard Rattle. I could swear it was coming from the passenger side and thought it was in the glove locker. I ended up running a strong magnet EVERYWHERE and hit gold on the trim along the top of the screen to the right if the hard top latch. Removing the trim revealed a large torx bolt which had fallen out of the fixing bracket. Drove me mad until I found it. Turns out it’s quite common and there are posts on the US forum and even a YouTube video. Mazda Miata MX-5 (NC) windshield rattle fix - YouTube