I have searched for a few days and have found nothing. This is my last option before going into the dealer. A couple days ago my front passenger strut went out. I am familiar with the noises this can produce. After the strut completely crapped out a new noise started. When I am braking I hear a "humming" come on and then it goes quiet. The humming is similiar to the noise when you spray the washer fluid. Its not loud. Im sure its not the pads or rotors because it makes the noise even once i come to a complete stop. Im on stock suspension. No lowering springs. Any help would be greatly appreciated.

 

Edit: the humming is at random. It even made the noise when I first started the car. It hums when I turn, accelerate, brake. I can not repeat the noise either. Its random but always lasts about 5 seconds. Always the same pitch as well. Never louder or quiter.

 

Fuel pump? How high would you describe the pitch? I'm not sure that'd happen at random in short bursts. When I had a noisy Walbro, it was pretty much noisy all the time, and you could hear it clearly inside and outside the car. I'd definitely describe it as a "hum" though.

 

Fuel pump is stock if that helps. Pitch is not high at all. Its not low either, no bass to it. Its very similiar to the sound of the washer fluid sprayers turning on. Its also not very loud. Could this be a sign of the fuel pump going bad?

 

So, just to be clear, this happens even when your not driving? You could be completely still with the car at idle and it happens?

 

Yes, it is completely random intervals. The humming always last about 5 seconds. Its always the same pitch, never louder or quiter. This morning I turned to car to "acc" and I heard the noise. This leads me to believe its the fuel pump. Its an original oem fuel pump if that helps.

 

Sounds like the fuel pump. The pump primes before starting the car.

 

Thats why I think its the fuel pump. This is my first evo and im learning as I go. Thanks for all the replies. Now I have had the car for almost a year and have never heard this humming noise before. Is that a sign that the fuel pump is going out?

 

Sounds that way to me. See if you can get someone to put the car in the on position for you and put your ear near the back seat/trunk area... See if it is louder there. If that's the case, get rid of it and throw a Walboro in there. GL!

 

Ironically I bought a Walbro last week and it should be here any day now. Thanks for the input everyone!

 

Be sure to let the EvoM community know if that solves your problem or not

 

UPDATE: I had Coilovers installed and a Walbro. Did not fix the humming noise. Today all 3 ACD lights came on at once. Now I believe the humming noise I hear is the ACD pump. If I can hear the pump it leads me to believe it could be the pressure sensor. Im just going off of what I have read online. Sorry if I seem like an idiot! Any opinions on this would be greatly appreciated.