Recently, I've started hearing kind of a soft metallic rattle just before I upshift, happening most noticeable in 1st and 2nd gear, and a little more faintly but still audible in 3rd gear. I've had the car for about 13 000 km (8 000 miles) and am going to be changing the MTF this weekend. Anyone know what this could be? I'll report back after the fluid change as well to see if anything will change.

Background on my driving:
For about the past 8 weeks I've been driving my 97 DX 70 km per day highway, and before that I was driving it maybe 20 km per week city. It has about 123 000 km on it (about 76 500 miles).

Thanks for the help.

 

heat shield? Mine did the same thing and it was the heat shield for the cat.

 

I agree. Check whether any exhaust heat shields are loose or cracked. On my 97 DX, I had the same problem that was caused by a hairline crack in the heat shield for exhaust pipe A. I needed to look very carefully to find it.