General Noise that appears between 1500 RPM and 2000RPM

[Hill Billy]

The offending cooling hose has been replaced and the noise is now gone. Apparently inside this hose is a small ball that was rattling causing this odd noise once the engine warmed up. It only affected some Grendiers and a new part number replaces this older version. I am so happy now that i can just hear the growl of the diesel

Hi there. Was the noise between 1500 and 2000rpm in neutral (revving engine) or only under load?