I have a 08 H3 Alpha with a air docs intake installed and its running like a bearcat.A couple weeks ago I noticed a air sucking sound comming from the front of the engine somewhere when the engine is at " idle ".It does not sound like its comming from the intake pipeing but rather in front of the engine somewhere,and it only does this when the engine is cold and idleing.After driving around and the motor is at running temp I do not notice the air sound at all.Its got me stumped on why it makes this noise,and only when the engine is cold.Anyone have any ideas ....

 

Thank you for the kind words on the intake.


The "noise" you are describing is from the clutch fan. GM trucks utilize a clutch on their radiator fan that uses temperature to run the fan at the engin RPM, or let it coast causing less drag on the engine. You are hearing the fan grab air and move it, when the temp rises, the fan coasts and the sound gos away.............the fan never stops spinning, just spins slower.

 

Thanks for the info Doc..