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I just purchased a NB8B yesterday with 135,000km on the clock

All seemed fine when I test drove it a few weeks ago.
However, on the way home yesterday, it suddenly developed
two issues.

1. There is a fairly loud strange noise emanating from the front of the engine
2. There is a noise when applying the brakes from the passenger side rear of the car

All responses will be appreciated

Rdster wrote:1. There is a fairly loud strange noise emanating from the front of the engine
2. There is a noise when applying the brakes from the passenger side rear of the car

Both really depend on the type of noise as to potential reasons, and severity.

It's impossible to diagnose this kind of thing online, so you're best to have someone look at it in person.


Anyway, the brake noise is probably something as simple as glazed pads (which can squeal), low pads (some pads have a small metal "sqeualer" which is there to make an annoying noise before they wear out completely)
Or if it's a grinding noise it may be that the brake pad is totally worn down and grinding the backing plate into the rotor.

But there's also 1000 other possibilities, everything from a tiny rock caught in the caliper, through to a wheel bearing ready to collapse.





Engine one, even more possible causes.
But start off by trying to narrow down the location of the noise to a component. If it's a squeak/squeal it's probably just a belt/pulley/bearing somewhere that's wearing out.

Can you get any vaguer?
Take it to a mechanic.

I made a audio recording of the noise, but I am unable to attach it to this post.

It's a loud warbling sound that increases and decreases with revs.

The rear disc noise is a 'clunk' when braking.

I have owned many MX5 in the past, but never had these two particular issues.

Rdster wrote:It's a loud warbling sound that increases and decreases with revs.

Does it eventually stop ? Look at the belts for wear on the edges. Also check for Mariah Carey, Céline Dion or the singing budgyunder the bonnet.

Rdster wrote:The rear disc noise is a 'clunk' when braking.

Almost normal to be honest. Check that the anti rattle pads are installed, the slider pins are not jammed and the hand brake is adjusted properly. While down there swapped the pads (inner to outer).

Magpie - Thank you for responding

The warbling sound is a mid tone. It's a very solid sound, and not the high tone sound associated with squeaking belts.
The belts visually look ok.
The noise never goes away, it's always present.

In regards to the rear brake noise - I did notice that the shims are missing on the side in question.
I will inspect the slider pins, handbrake etc as suggested.

Magpie wrote:

Rdster wrote:It's a loud warbling sound that increases and decreases with revs.

Does it eventually stop ? Look at the belts for wear on the edges. Also check for Mariah Carey, Céline Dion or the singing budgyunder the bonnet.

Rdster wrote:The rear disc noise is a 'clunk' when braking.

Almost normal to be honest. Check that the anti rattle pads are installed, the slider pins are not jammed and the hand brake is adjusted properly. While down there swapped the pads (inner to outer).

Does the warble increase in noise with engine RPM when stationary in neutral? Or only with increased wheel RPM? ie: is it engine based or driveline?

ManiacLachy wrote:Does the warble increase in noise with engine RPM when stationary in neutral? Or only with increased wheel RPM? ie: is it engine based or driveline?

The warble noise increases with revs when stationary in neutral, and does the same when in gear and driving down the road.

135k kms - has the timing belt & water pump been replaced?
Warble might be a bit of a concern - a handful of NBs on here have had a crank issue similar to the early NA6.

Magpie wrote:

Rdster wrote:It's a loud warbling sound that increases and decreases with revs.

Also check for Mariah Carey, Céline Dion or the singing budgyunder the bonnet.

... also check Magpie isn't under there ...



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Ouch

I found two videos on youtube with the identical sound

https://www.youtube.com/watch?v=ElRYQCFekmo&app=desktop

https://www.youtube.com/watch?v=ceFYvo35mQ8&app=desktop

Well sounds like it a belt


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135k kms - has the timing belt & water pump been replaced?

Any visible crank pulley wobble when revved?

Go to a mechanic as Bruce said and get a report on it. You could have been dudded and if so you still may have some "rights". I would also talk to the seller and tell them you have a problem and see what they say. If its a dealer you will have a comeback and private sale you still may have some rights. A seller may have misrepresented the car.

Getting guesses on line is not going to lead anywhere in my opinion.