All,

For the past 2 days I have noticed an odd buzz like sound. The only thing that has changed is that I just had an oil change.

Some basics, 08 TSX, Auto, 65k, no visual damage / loose covers.

When the car is under average load while accelerating there is a buzz that happens around 3k-5k RPM. Usually lasts for 1-2 seconds. I can not get it to replicate when the car is parked in neutral nor when coasting in neutral and reving the engine. I can make it happen only when I am in 1st or 2nd gear. Not sure if it happens in 3rd-5th as the wind noise / road noise may cover it. I can replicate it pretty easy by letting off the gas and coasting down to around 20mph and then 3/4 throttle. The car may or may not down shift to cause the noise.

Now for the sound. It sounds almost like a loose baffle or a heat shield. My wife thinks it sounds like the buzz on some aftermarket exhaust systems. The sound is pretty equal from driver and passenger side. It appears to be forward of the driver's head and low on the vehicle.

I am at a loss, thoughts anyone?