2011 Mazda6 FWD 2.5L I4 6-speed manual 85,000 miles
5-6k miles ago (2-3 months) I started to notice a "rustling" sound coming from the front of my drivetrain, but only when in gear above 4,000 RPMs. The sound comes from directly beneath the center console, if not a little bit forward and under the HVAC controls.
The sound is generally light--there is no knocking or pinging. It sounds like paper is being aggressively shuffled, or like shaking a branch with dead leaves.
Here are some observations on this noise:
- Has never occured below 4,000 RPMs
- Occurs all through powerband above 4,000 RPMs
- Occurs in any gear
- Occurs only when transmission is in gear and car is at speed
- When car is at speed, I press in the clutch, press the accelerator to >4,000 RPMs, no noise is made
- When car is at speed, I shift to neutral, press the accelerator to >4,000 RPMs, no noise is made
Any thoughts what could be causing this unusual noise, that occurs only when the engine/transmission is bearing the load of the automobile?
My daily commute is mostly highway, and includes many hills between Vermont and New Hampshire--hence why I encounter >4,000 RPM frequently enough to notice.