recently my car has been making a humming noise, a lot noticable noise (which i haven't figured out yet). It doesn't compromise driving or anything so not too worried.

However a day or 2 ago my car was idling a bit low so i just turned the screw to turn the idle up and it's at about 7 or 800.

Well now after the car is at normal operating temperatures and i roll to stop and press in the clutch, the tach goes down to 1000 stops, up to 1100 or 1200 for a second or 2, then humming noise, then drops to 700-600 with the humming/buzzing noise continuing or stopping.

If it blip the gas, does the same thing consistently. I have no clue what this is, but it is getting annoying. ANY IDEAS?

 

My idle bounced up and down when I didn't have my IAT sensor hooked up.

 

I thought something might have been disconnected or bad sensor, but they all seem fine...

I was wondering if build up on the inside of throttlebody could be causing the humming noise and/or the idle problem or a cracked intake gasket?

 

Bump for any suggestion

 

bump because i am having the same problem!

 

as for the idling i would say try cleaning the iacv.. i dont know about the humming good luck

 

the noise from my y8 sounds like its coming from tranny?