My engine has a whinning noise what could this be?

Tough to know via the Internet....But since you mention when you take your foot off the gas, I almost wonder if you are hearing a resonating vibration from the idle air control valve in the intake manifold? That would make a noise; not sure if the noise would be described as "Whining". A good first hand inspection would be needed. See a local shop near you - click the link for some near you. http://repairpal.com/lincoln-repair-in-las-vegas-nevada .