- My model of MX-5 is: 25th anniversary
- I’ve just had my mx5 air con regassed ready for trip to France. Now the air con makes an intermittent graunching sound when driving. However when I look underneath, it seems seems more of a clattering sound . Air con seems to work fine but I don’t want to travel over 2000 miles without knowing what this might be. Anyone got any ideas ? Could it have been regassed incorrectly ? Any help appreciated.
Well, I hope it’s not your compressor. 
Mine on my Volvo made exactly the same sounds etc etc.
Sounded like a load of bolts in a tin can after a while.
The electronic clutch engaged/disengaged but in the end it exploded causing absolute havoc.
Yes, mine also continued to pump out cool air too.
Does the noise stop when the compressor is switched off?
If so my best guess is the compressor.
All those little pistons inside can go wrong.
An expensive warranty (thankfully) job.
Another common fault is actually “too much gas” put in the system. But probably wouldn’t make the clatter when in use. 
Get that checked tested ASAP.
If so, put a new belt on too.
Many thanks - that’s really helpful. There was no worrying sound before the regas so I am hoping it’s simply too much gas rather than the compressor. I am getting it retested
A quick update on the air con issue and a warning for others. It turns out that my aircon had been overgassed. It was eventually sorted by the mobile aircon company but they were reluctant to admit what had happened. Once rectified, aircon drained down and regassed, the guy admitted this was probably the cause. Beware folks !