Get in and start my truck after work last Tuesday. Started just fine but I got this strange whining sound from the engine compartment. Pop the hood to investigate thinking I might be loosing the injection pump at a mear 23K miles. Well the noise, which sounded almost exactly like a supercharger whine, seemed to be coming from the engine as it was the same on either side of the truck. All I could think of was the CP3 or the turbo bearings. I have heard a similar noise from large rigs. I cant quite explain but it sounded like a loud radio frequency, supercharger whine or alternator with a huge load on it. NOT a whistle. So I took the long way home down the interstate at just above posted speed limits. After 40 miles and 1 hour later, no whine. It has not done it since. Since the noise seemed to center in the engine I also thought about the cam gears as I understand these motors are gear driven and not chain driven. Is that correct? Any ideas?

 

I forgot the mention that the whine did increase with engine speed. Any ideas? Beuller? Beuller? Beuller? Anyone?