Intermittent belt squeal sound

Technical Area Engine, Transmission, Exhaust etc
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  1. My model of MX-5 is: __2019 RF ND2 (at 42,000 miles)
  2. I’m based near: __Horsham
  3. I’m looking for technical help or recommendations on: __belt squeal

For the last week ive started hearing the occasional sound which i think is belt squeal/slip.

What’s odd is that it doesn’t happen on cold start or in general under load but most often at low to no throttle especially when you lift off the throttle.

(Occasionally if you are booting it hard up into the higher rev range i think it occasionally happens here as well but my cars quite loud so hard to be sure :slight_smile: )

It doesn’t happen all the time only occasionally and despite a number of test drives its strangely hard to reproduce reliably

I’m assuming it either a belt or bearing showing signs of wear but would be interested to hear peoples opinions/experiences with similar sounds

Just for reference : about 5 weeks ago i had a Rotrex Supercharger installed by BBR GTI (first customer apparently on an ND2 - yikes!) and its been fine for those past 5 weeks.
This included : BBR spec revised ancillary belt and tensioner

NB : ive also asked BBR for advice but heard nothing back yet

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Funny, my NC3.5 does the same, just a couple of weeks after a BBR Supercharger install. Did mention it when they changed the running in oil, but forgot to ask them afterwards what they thought…….still does it when hot.

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To answer my own post: turns out the problem was a faulty belt tensioner.

Now replaced and sound has gone, will follow up this post in a month or so to confirm it doesn’t return.

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