Noisy rear

[JBT]

Nature of the beast with the top up it seems. Mine has OEM exhaust and growls like that too......but not to the \"ear plug\" extent. OEM and replacement Torsen diff and three different brands/types of tyres made no difference. Bearings are fine. Inaudible with the top down.

Remedy: drive with the top down except in inclement weather.

[irwin83r]

so you saying its the soft top material flappin in the wind?

[Uncle Arthur]

and here I was thinking you were talking about the morning after a big curry........

Even the Loch exhaust whileloud doesn't require earplugs. Perhaps the exhaust needs an additional inline resonator after the catalytic convertor to quiten things down more.....

[Bevan]

Perhaps the exhaust needs an additional inline resonator after the catalytic convertor to quiten things down more.....

Even with the engine turned off?

[StanTheMan]

i still have the original excaust from 17 years ago
On the free way. It has a nice deep almost throaty sound to it.in fact the Mania CAI is about the same decible when putting on the tourqe.

i would re think the whole exsaust if you need to wear earplugs.

Now everyones idear of noisepolution is different.....but this sounds a little excessive. If you come from the doof, doof crowd.....there is even more reason for concern. if you get my drift.

make it to a MX5 meeting. Third Sunday of every month you are welcome to come for a ride in mine if i'm there. we should take yours for a drive as well. there is some pretty cluey members and a lot of knowlege about on most of the MX5 club of NSW runs.

[sirbob]

Just a stab... Did you have a look at the rubber boot around the base of the gear stick? Have heard of these wearing out and allowing the full road/gear/exhaust noise to enter the cabin unimpeded. The reason you would only hear it with the roof up is due to the enormous amount of wind noise masking the sound...

Dunno, thats my thoughts anyway...

On the topic of exhaust noise, how large is your exhaust? Mine is 2.25', with extractors, and 3.5' tip, and i dont particularly notice a \"roar\" persay, it is noisy, but not to the extent of requiring earplugs, and it does drone a little on the highway...

Maybe you should just try driving harder to mask the unwanted noise with exhaust noise...

[Bevan]

Guys, it wouldn't have anything to do with gears, exhaust, intake etc. Although he has a loud exhaust, he said the noise is still there and unchanged with the engine off. So this would rule out anything to do with the engine, gearbox, diff, exhaust etc.

My best guess is there's someting attached to the car somewhere that's causing vibrations when the car is moving or making noise when wind passes over/through it. Or it could very well be the wheel bearings, as you suggested. I think this is quite a cheap exercise.

Maybe that should be your next fix?

[JBT]

My best guess is there's someting attached to the car somewhere that's causing vibrations when the car is moving or making noise when wind passes over/through it. Or it could very well be the wheel bearings, as you suggested. I think this is quite a cheap exercise.

I think it's simply road and drive train noise amplified and transmitted into the cabin which can only be heard with the top up - even with new gear shift boots. It starts when the car starts moving and doesn't matter whether it's under load or not. May just be an NA problem (haven't compared with another NA or later car). I've even gone to the extreme of having mine run on a hoist whilst listening to the bearings with a stethoscope - nothing heard outside but still growling inside the car.

[Gramps]

At highway speeds the noise is so great I have resorted to earplugs.
So I changed the tyres - no difference.

There is always a lot of road noise, especially with the top up, but it could be noise from a coarse tyre tread pattern. What tyres did you fit when you replaced them?

[JBT]

It is there almost until the car stops - so I don't think it is tyres.

Why not? The tyres are turning until the car stops.

Another way, not necessarily conclusive, to check the bearings is to drive the car at constant speed and weave left to right. You'll need a big empty carpark or an empty multi-lane road to do this.

If the noise changes significantly when turning this may indicate a dodgy bearing.......the next problem is to identify which side. Change both and be done with it anyway if you suspect a worn bearing.

[Bevan]

I found this on the big forum:

I have a 99', automatic with Michelin 195/50 R 15(82V)(SX-GT) Pilot SX tires.

Is anyone who has these tires experiencing a tremendous amount of noise
from them. These seem to have an exceptionally loud hum that is actually
painful between 60 and 70 mph.

My husband can't hear it, but I attribute that to hearing loss from loud
classical music.

Laurie

Try inflating your tires to 30 psi up from factory recommended 26 psi. The
tire noise should be dramaticaly less, but the ride may be a little harsher. I
noticed the same thing except the other way around. After servicing the car at
a dealer for the first time, on the way home I noticed tire noise which was
not there before. Turns out the dealer deflated my tires down to the factory
spec of 26psi, the ride however was much smoother.
Serge.
99 Red Sport.

Worth a try?

[Garry]

If your car is a later model NA then they run stuff all sound proofing compared to the earlier NA's. My '96 was so loud I used to pray for red lights so I would have to stop moving and the noise would stop. Anything over 70kmh would totally drown out the stereo. Though I'm not sure I needed to wear gearing protection but the noise was extremely tiring on a long trip.

I added some more sound proofing and the noise was reduced to acceptable levels. Though I would never call it a quiet car. I found a new sound proofing product recently that I installed into my SP and with the hardtop on I would go so far as to say it's a quiet car now. It's still a bit noisey with the soft top though as external noise is transmitted through the soft top material. There's not much I can do about that other than to get a soft top liner but it's not worth the effort seeing as I have a hardtop.

[JBT]

Worth a try?

I've had Firestone 185/60, Yokohama 185/60 and B'stone Turanza 195/50 at all pressures between 26 and 36 - no effect. Changed diffs (open to Torsen) and no effect. They are just noisy little buggas with the roof up.

I reckon Garry is on track. I'm thinking about some sound proofing stuff that one of the blokes had samples of at the MG Club run on Wednesday. Trouble is, I rarely drive the car with the roof up. I think the growl/hum noise is so bad that, quite frankly, I'm stuffed if I know how they could have sold the cars to anyone on a demo drive with the top up, especially considering the prices they sold for 11 years ago.

[Gramps]

When I test drove my first Five buy, a '99 model, it was so noisy I was sure it had diff problems and I passed it up and went looking for an alternative. In the end I came back to the '99 car because they were uniformly noisy. I recall that one guy who was concerned with the noise in his car even put it on the hoist and ran it trying to detect the diff noise. It is on the forum somewhere in a very old thread. Anyway, there was no diff noise while the car was on the hoist. The quietest car I drove at the time was a run down Five with very little tread left. That car was quiet - and that was the reason.
Next time get the new Precedas, Garry has found them a very quiet tyre compared to his old ones. I am going to replace my Turanzas with them too.

[JBT]

Who makes Precedas?

Google

It probably won't help much with the noise though. I'd wait until your current tyres 'need' replacing.