Has any one any views on or experience of the following? At 3500 miles a metallic sounding whine from gearbox suddenly developed, only evident in 4th gear at between 3500 and 4500 rpm. Its not very loud but clearly noticeable. Local dealer says that it is harmless and down to tolerances resulting in 2nd gear "resonating" with 4th gear at these revs. Apparently this condition is not unknown on MX5's. There is a fix although it offers no guarantee of eliminating the whine completely. Dealer recommends leave best alone. (1/01)
I've had this gearbox noise in my last 1.8 mk1 and now in my 1.8mk2, especially on acceleration in 4th gear. I quite like it! Adds to the aural experience :o) Never did anything about it and cars have always been fine. I think some people have talked about it on the miata list (or was it the US MK2 list can't remember) and tried to get dealers to "fix" it. Seems to be a feature (at least on the 2 5s I have had!) (1/01)

Our Mk2 1.8 has had this since new - also noticeable in 3rd between the same rev. range, although a lot quieter than 4th. I have read several threads on the miataforum about this and concluded that it's nothing serious. The noises are only intrusive when the stereo is off.

Although, I have notice recently that I also have another noise now at around 4000rpm - this sounds much more like the resonating heat shield problem which is also often discussed.

I suppose I'll have to take the car into Mr Mazda sometime to get it checked out, but it doesn't really worry me too much. (1/01)
I had some thing similar due to the gear bix gaitor splitting on a clutch change. It was nothing to worry about, just noisy at certain revs. - I had it replaced. No guarantees it is the same thing though. (1/01)
It would seem quite common. I had it on my white 1.8 and the Cal has the same thing. In my case it comes in under power at about 55mph and goes again at just over 60, but disappears if you lift off. In both cases, changing to Redline made no difference, but it never got any worse in 30,000+ miles. (1/01)