As the title said I have been hearing a loud buzzing noise coming from the front end of the truck. It seems as it is coming from the engine but almost as it is right under the dash. The noise sounds almost as if I have the wine of a super charger. The noise is constant from start up to acceleration. It doesn't matter if it is a cold or hot start. I am having a hard time diagnosing this, I have checked all the fluids. Somebody please help.