The other day I went to the gas station and filled up with gas and noticed when I started the car the was a low toned howl. When I hit the gas it went away, but now whenever I hit the gas you can hear the howling coming from the intake manifold when you hit approx. 2500 rpms. I doesn't do it any where else. It doesn't matter if the car is in neutral or if you have the clutch pressed. However it doesn't do it when your driving. Power is still there and oil pressure is still there. I have checked my belt already. Please help.

 

what about the pulleys? or the accessories? take off both belts and start it up and see if the noise goes away. that'll eliminate all that as possibilities. good luck
chris