what is that noise!?
Discussion
Hello,
I’m currently driving my second Mk1 MX5 both have a grating sound when in gear and you take your foot off the gas, I’ve asked other drivers if they have the same thing and most say yes. My first mx5 had done 45k miles, and my new one has done nearly 100k and it's a little louder.
But what is that noise? Bearings in the gearbox? The only way I can describe it is a bit like straight cut drop gears in an A series engine from classic mini's.
It’s silent on idle and acceleration but deceleration is where the noise starts, definitely grating and you can feel it through the gear stick.
Edit: worth noting, on my current mx5 i also have changed gear box oil and added molyslip but made no difference!
Can anyone shed some light on it and put my mind at rest?
Thanks!
I’m currently driving my second Mk1 MX5 both have a grating sound when in gear and you take your foot off the gas, I’ve asked other drivers if they have the same thing and most say yes. My first mx5 had done 45k miles, and my new one has done nearly 100k and it's a little louder.
But what is that noise? Bearings in the gearbox? The only way I can describe it is a bit like straight cut drop gears in an A series engine from classic mini's.
It’s silent on idle and acceleration but deceleration is where the noise starts, definitely grating and you can feel it through the gear stick.
Edit: worth noting, on my current mx5 i also have changed gear box oil and added molyslip but made no difference!
Can anyone shed some light on it and put my mind at rest?
Thanks!
Edited by BlackBonnet on Friday 3rd October 16:25
As your enquiries have found out, this noise is fairly normal. Not all of them do it and some are louder than others.
Replacing the gearbox oil with a good synthetic oil usually helps a bit but won't make a big difference. I would expect the same improvement (or lack of it) from Molyslip.
Have you checked the gear-lever rubber boots? If these are split it usually results in more noise being transmitted into the cabin. Replacing them and topping up the turret oil will improve the gearchange and can make a minor improvement in the noise levels too.
Unfortunately, much of the noise is transmitted up the hood drain-tubes so you will never get rid of it altogether. Even replacing the gearbox is no guarantee.
Most cars actually make the same noise but they usually have more sound-deadening than an MX-5.
Later cars have more sound insulation around the gearbox so are usually a bit quieter.
I am part-owner of an L-reg Mk1 1.6 which we've stripped out for track use so all the carpet & sound insulation has been removed. The gearbox in that is louder than that in a Westfield 2000S with straight-cut a sequential gearbox that I drove a few years ago on an Evo Magazine road & track test
Replacing the gearbox oil with a good synthetic oil usually helps a bit but won't make a big difference. I would expect the same improvement (or lack of it) from Molyslip.
Have you checked the gear-lever rubber boots? If these are split it usually results in more noise being transmitted into the cabin. Replacing them and topping up the turret oil will improve the gearchange and can make a minor improvement in the noise levels too.
Unfortunately, much of the noise is transmitted up the hood drain-tubes so you will never get rid of it altogether. Even replacing the gearbox is no guarantee.
Most cars actually make the same noise but they usually have more sound-deadening than an MX-5.
Later cars have more sound insulation around the gearbox so are usually a bit quieter.
I am part-owner of an L-reg Mk1 1.6 which we've stripped out for track use so all the carpet & sound insulation has been removed. The gearbox in that is louder than that in a Westfield 2000S with straight-cut a sequential gearbox that I drove a few years ago on an Evo Magazine road & track test
MX-5 Lazza said:
I am part-owner of an L-reg Mk1 1.6 which we've stripped out for track use so all the carpet & sound insulation has been removed. The gearbox in that is louder than that in a Westfield 2000S with straight-cut a sequential gearbox
*removes carpet and sound deadening*
Edited by hcanning on Monday 6th October 11:20
Hi.
I own a 1991 1.6 eunos import. It does exactly the same thing and I intend getting rid of it if I possibly cxan as its doing my head in! My car is perfect part from the noise. I've found on various forums that it could be the spiggot bearing or synchro play.
Whatever it is I'm going to have the clutch replaced along iwth the spiggot. I'll let you know if it is cured.
I own a 1991 1.6 eunos import. It does exactly the same thing and I intend getting rid of it if I possibly cxan as its doing my head in! My car is perfect part from the noise. I've found on various forums that it could be the spiggot bearing or synchro play.
Whatever it is I'm going to have the clutch replaced along iwth the spiggot. I'll let you know if it is cured.
I think the noises associated with play in the synchro is usually restricted to 4th gear and usually at about 4krpm. This is a very common noise on MX-5s that usually gets blamed on heat-shields (it sounds the same). The thing that identifies it is that it only happens on acceleration in 4th at about 4krp (and to a lesser extent 2krpm).
The spigot bearing sounds much more likely. Keep us updated with your findings
The spigot bearing sounds much more likely. Keep us updated with your findings
OnlyMX5ives said:
Perhaps I'm deaf...
I've owned around a hundred MX5's and never heard a noise you describe from any of them.
Who? Me or the OP?I've owned around a hundred MX5's and never heard a noise you describe from any of them.
If it's me - the 4th gear 4krpm is a recognised issue and there was a Mazda Service Bulletin relating to it. It was originally fixed by rebuilding the gearbox with new components to reduce the slack in the 1st-2nd gear synchro to stop it vibrating but this results in a notchier gear-change. They later changed it to a replacement clutch to take out the vibration though I have no idea how that works.
I know this was a particular problem around 97-98 as they opened up the tolerances on gearbox components a bit to reduce costs and later tightened them up again as it clearly wasn't worth the saving. Previous and later cars can still suffer the same problem but it's much rarer.
I've been posting a thread on the MX5 Owners club as my Eunos is making a similar noise - it only happens under a very light engine load or when the engine is braking the drivetrain, mostly in 3rd or 4th gear.
http://www.mx5ocforum.co.uk/viewtopic.php?t=67161
it sounds sort of like a load of pebbles being poured down a metal pipe - is this what your noise sounds like? It only seems to happen once the vehicle has warmed up, perhaps 5 or so miles. At first I wondered if it was pinking, but it doesn't happen under normal or hard acceleration, just on very light throttle load and mostly under engine braking, so that doesn't really fit.
The car has a brand-new recon engine, new clutch and new spigot bearing, and also a stripped-out interior with no sound-proofing and very thin carpets.
Perhaps this new clutch I used is the cause of the problem? Do Mazda recommend a specific type of clutch to cure this vibration?
http://www.mx5ocforum.co.uk/viewtopic.php?t=67161
it sounds sort of like a load of pebbles being poured down a metal pipe - is this what your noise sounds like? It only seems to happen once the vehicle has warmed up, perhaps 5 or so miles. At first I wondered if it was pinking, but it doesn't happen under normal or hard acceleration, just on very light throttle load and mostly under engine braking, so that doesn't really fit.
The car has a brand-new recon engine, new clutch and new spigot bearing, and also a stripped-out interior with no sound-proofing and very thin carpets.
Perhaps this new clutch I used is the cause of the problem? Do Mazda recommend a specific type of clutch to cure this vibration?
Edited by anonymous-user on Tuesday 7th October 12:02
Thats exactly my problem!! I've been on the forums too. If I had the answer I would be a happy guy as its the only thing that spoils an otherwise great car.
I cant afford the clutch just yet, but from your post it might not cure the problem.
I did have MX5 City say it was the Diff, with noise travelling from there up the driveshaft.
Again, another costly issue.
I've taken to using the clutch a lot to eliminate the noise.
Still love my machine to bits.
I cant afford the clutch just yet, but from your post it might not cure the problem.
I did have MX5 City say it was the Diff, with noise travelling from there up the driveshaft.
Again, another costly issue.
I've taken to using the clutch a lot to eliminate the noise.
Still love my machine to bits.
Edited by iantrinsic on Tuesday 7th October 13:11
Interesting read that, thanks. - I currently have 2 Roadsters (a crap one I'm rebuilding and a good one that works) - both are almost identical 1992 mk1s - the crap one has a nice easy 1st to 2nd action, but makes this noise, whereas the good car has a really awkward 1st to 2nd change but doesn't make this noise.
I'll change the diff oil just to be sure it's done (I've just refilled the gearbox anyway) but looks like I'll just live with the noise (and the sweeter gearchange action) and see how it goes.
I'll change the diff oil just to be sure it's done (I've just refilled the gearbox anyway) but looks like I'll just live with the noise (and the sweeter gearchange action) and see how it goes.
Quote from one of the links within links within links etc...
somebody said:
On the 1.6L Mk1's this is almost certainly transimission noise generated due to the slightly worn tolerances between individual gears/spacers. The noise is transmitted along the driveshaft to the rear diff where it can be heard as a metalic "rushing", "buzzing" sound. In the case of my 1.6L this got rapidly worse after going FI to the point where I didn't like driving it (worst IIRC between 2500 and 3000rpm during light deceleration).
Mazda recognised this as a problem and in the early days would replace gear sets (as some were worse than others, lets say all the gears were at the 'looser' end of the tolerances), but resolved the problem on 1.8L mk1s by incuding a rubberised companion flange (damper) between the rear diff and the drive shaft. See here http://www.miata.net/garage/diffguide/index.html
Mazda recognised this as a problem and in the early days would replace gear sets (as some were worse than others, lets say all the gears were at the 'looser' end of the tolerances), but resolved the problem on 1.8L mk1s by incuding a rubberised companion flange (damper) between the rear diff and the drive shaft. See here http://www.miata.net/garage/diffguide/index.html
Basically, there are a number of noises that all get confused in threads like this.
1) As the original poster has reported, noise on deceleration. Not limited to any particular gear or engine speed. We have this in our shared stripped out track car. It's much louder now that it's been stripped out than it was when it had carpets but it was still noisy even then.
2) The one I mentioned. Only occurs accelerating in in 4th gear at about 4k rpm for a few hundred rpms. I had this one on my old 1998 Mk1 1.8 Berkeley. It was "repaired" with a new synchro but it only improved it a bit and made the gearchange tighter (too tight when cold).
3) Heat shield rattles. These tend to occur on acceleration but can also be on deceleration and usually at certain revs but in any gear. I've been lucky enough never to have experienced this as it can be a pain to identify.
1) As the original poster has reported, noise on deceleration. Not limited to any particular gear or engine speed. We have this in our shared stripped out track car. It's much louder now that it's been stripped out than it was when it had carpets but it was still noisy even then.
2) The one I mentioned. Only occurs accelerating in in 4th gear at about 4k rpm for a few hundred rpms. I had this one on my old 1998 Mk1 1.8 Berkeley. It was "repaired" with a new synchro but it only improved it a bit and made the gearchange tighter (too tight when cold).
3) Heat shield rattles. These tend to occur on acceleration but can also be on deceleration and usually at certain revs but in any gear. I've been lucky enough never to have experienced this as it can be a pain to identify.
Hi Guys,
Just to throw a spanner in the works, I own a MK1 import and have had it about 18 months. For anyone thinking of getting their clutch changed be warned that afterwards you will probably hear a tinny rattle on the overrun about 3000rpm, its where the gearbox vibrates on the mounting framework, not sure how to fix it but I think its where garages tighten the bolts up to bu**ery with impact wrenches.
As for the gravely sound I cant say I have experienced that one!!
Just to throw a spanner in the works, I own a MK1 import and have had it about 18 months. For anyone thinking of getting their clutch changed be warned that afterwards you will probably hear a tinny rattle on the overrun about 3000rpm, its where the gearbox vibrates on the mounting framework, not sure how to fix it but I think its where garages tighten the bolts up to bu**ery with impact wrenches.
As for the gravely sound I cant say I have experienced that one!!
Gassing Station | Mazda MX5/Roadster/Miata | Top of Page | What's New | My Stuff