Engine Whinning

3-4 days ago i began hearing a whinning noise coming from the engine. It is low pitched when idling and becomes high pitched when accelerating. Any ideas?

Every 60k the hood has to be opened and scheduled maintenance realized. When not done, all kinds of noises will be heard until 'after 120k' the noises tend to cease totally... Pls check out the vehicle reg papers and tell us type and model, usually that determines whats under the hood: this defines possible noise sources. Also the the mileage and maintenance history is a definite factor in the guesswork, pls elaborate more.

:(= swap the belts:)