Humming noise

[StarPD]

Another unusual question for the experts here.

I notice in my new-to-me 2005 Q45 a hum that is sensitive to throttle setting. Either on cruise bcontrol, or manual throttle control. It changes in volume, but not pitch. It seems to be loudest at throttle setting changes. It goes away when the throttle is closed or opened hard on acceleration. It's most noticeable when going over a freeway overpass on cruise control, just before cresting the rise, and after initially entering the return to level pavement. On closed throttle or accelerarion, it goes away completely, and the shutoff of noise is positive and definite. I cannot isolate where the hum is coming from. Turning the sound system and climate control on or off makes no difference. I can't find any other system that I can control that alters the sound either, outside of modulating the throttle. It cannot be heard under no load, when stationary, either at idle or increased RPM. It's not a wind noise, as it's throttle position sensitive when driving only.

My last Q, a '94 Q45t had the dreaded fuel pump hum. This sounds similar, but not exactly the same. On the '94, it tended to be more constant, and never actually went away. It was louder too.

At 24k miles, my new Q shouldn't be experiencing fuel pump wear.

Any ideas?

[elwesso]

The Q is throttle by wire so it could be the motor making noise. would fit the symptoms too.

[maxnix]

Good guess, but the butterfly motor is not constatntly turning.

Sounds like time for a trip to the dealer. Maybe even look at the Infiniti dealer extended warranty while you are still eligible.

Any pictures of your car posted?

[elwesso]

What i was thinking is maybe the throttle needs to "relearn"

Accelerator Pedal Released Position Learning DESCRIPTION“Accelerator Pedal Released Position Learning” is an operation to learn the fully released position of the acceleratorpedal by monitoring the accelerator pedal position sensor output signal. It must be performed each timeharness connector of accelerator pedal position sensor or ECM is disconnected.OPERATION PROCEDURE1. Make sure that accelerator pedal is fully released.2. Turn ignition switch “ON” and wait at least 2 seconds.3. Turn ignition switch “OFF” wait at least 10 seconds.4. Turn ignition switch “ON” and wait at least 2 seconds.5. Turn ignition switch “OFF” wait at least 10 seconds.

[tt300z]

it may be to soon.....but maybe its a bad driveshaft bering....check it out