Mystery Noise Diagnosis

[Mojo72]

I'm getting an odd "tinny" noise that starts at around 2,800 RPM and am not sure where to look for the source. Could it be the engine, the auto trans, or a vibration? Has anyone else had this mystery noise? My Vibe has approx. 83.5K miles and it's never had a tranny flush that I know of.

[djkeev]

Hi,Check out the heat shields for your exhaust system, After a few years they can come loose and vibrate while driving, often at certain RPM's.Can you rev the car with it in park or neutral and make the noise happen or must you be driving??Good LuckDave

[Sublimewind]

^^ Agreed.. most of the systems won't make so much of a tinny sound as they are heavier than that.. I would look at heat shields as well... metallic clanks and such can be had from brakes, tensioner pulleys, any host of things... But without being able to hear it, we are shooting the moon..

[Mojo72]

Since having the transmission fluid changed at 86,539 miles, the mystery noise has virtually disappeared and the auto trans shifts much smoother and more responsively. I'm not sure what was going on with the trans because the fluid level was always normal, but did have a slightly burndt smell. My mechanic said that he found and cleaned "significant" metal shavings from each of the 3 pan magnets.