Lately I'v heard a strange metallic sound when decelerating at approxiamately 2250 rpm. I freaked out and checked the motor, with nothing seeming out of the ordinary I then found a thread on miata net (sorry) about the noise.

Supposably it can happen after a clutch change due to the ppf being slightly out of position and some other stuff. Problem being, the clutch was changed before I even bought my car, so there goes that idea (maybe).

The sound resembles almost a lose metal panel moving slightly, combined with a metallic grinding sound. I tried moving different parts like the heat shield to try and mimic the sound, but to no avail have i been able to determine it's source.

What is this magic?

 

You really have to figure out what part of the car it is coming from.

 

I have a 1992 and I have that same noise too ! I can't figure it out either

 

Hows the shifting in int he car? It is hard to shift at all? Where does the sound come from engine by or right beneath you?

 

Is the sound only on deceleration?

First thing to check is heat shields under the car. Also check the clutch slave cylinder for play and put a dab of grease on the end.

There's also a TSB related to a cable clip breaking an allowing the harness to rattle against the PPF

Miata Technical Service Bulletin

 

Wait! You have a 1.6 car and it only happens under deceleration. It might very well be the rear differential. They whine before they fail and the 1.6 differentials often fail.

 

Could very well be the differential if it's not the clutch, and I doubt that since it hasn't been changed.

 

It turned out to be the exhaust tip hitting the body work haha. The engine is at it's "roughest" (least balanced) at the rpm range at which the noise was occurring. Just moved the rubber mount across back to it's original position and clamped it. Problem solved Oh and IT DID occur under acceleration, just couldn't hear it because racecar!

 

Because giant ricer exhaust tip?

 

4 Inches isn't that big

https://www.miataforumz.com/attachme...712_232400-png

Culprit ^^^^^^ (No pic because I'm using school network)