1995 E320 humming throttle actuator
 

While retrieving codes last week, I noticed a significant amount of noise coming from the throttle actuator (directly under the plastic air intake) when the ignition was turned to the on position but the car was not running. It's a high-pitched squeal that changes pitch slightly when the gas pedal is depressed. The noise is constant....it also changed pitch when the codes I retrieved were being erased. I don't recall hearing this before. Is this normal or indicative of a faulty actuator or one that is on it's way out?

Thanks. Brian

Bump

Anybody with a M104 HFM (93-96 3.2L) could you help me out and turn the key to the run position (don't start the car), pop the hood and listen for noise around the intake manifold? I'd appreciate any help.
Thanks! Brian

On my E320 car, there is a constant buzz from the vicinity of the throttle actuator with the ignition on and the car not running. I'd say it sounds like a fuel pump. It does not change sound when the accelerator is pressed. I do not have EA on my car.

Thanks for checking, Paul!
Brian