I have an 07 RDX. For a while now I've noticed a very distinct sound from under the hood. I cant quite pin point what may be causing it, but it happens while accelerating. I hear it when the rpm's are high and the tranny shifts up and the rpm's drop. Right in there I hear a sound that sounds like a subtle burp.

Has anyone else noticed this on their RDX? I wonder if it's a normal sound or not.

 

Likely normal. The factory bypass valve makes a light "PSHH" sound to vent boost slightly during shifts.

 

It makes this noise at the same time as the "PSHH". So it's like a "BURP PSHH". My car has been at the dealer for the past three days and they cant hear it. I test drove it with them and I hear it still. They say all the sounds the car is making are normal.

The loaner car I got is an MDX. I should have requested another RDX to see if it makes the same noise.