Under acceleration i have a whining noise and gets louder the faster i go. It sounds like it's coming from the alternator but not sure do alternators make that kind of noise when there going bad or is a pulley. I can't figure it out and don't want to replace something that's not broke. Any suggestions?

 

My alternator made that same whinning noise for a few days, then died...........

 

I need a little more info. Is it a high or low pitch whining noise? does it change pitch with speed or when you go through dips in the road? With the truck parked, start it up and pop the hood. Can you hear the whining noise? If so, does it change pitch or volume when you throttle the motor?

 

The pitch gets higher the more gas you give the truck. When i pop the hood at idle you can't really tell it's there when you hit the gas is where you hear it. As for the pitch i wouldn't really say it very high it kinda sounds like a supercharger whine.

 

That sounds just like what mine did for about a week, then I replaced the alternator and it solved the problem. I described it exactly the same (supercharger).

 

Thanks for your help i'll replace it tommarrow and hopefully it will do the trick.

 

I would agree, I sounds like its your alternator thats about to go. Mine did the same thing. Just to double check, take off the sepentine belt (you'll have to do this anyway when you replace the alternator, so might as well practice now) - remember to take a picture or make a drawing if you don't have a diagram in your engine compartment so you can put it back together. Start the motor (without the belt) and listen if the sound is still there; then give it some gas, is the noise still there? If your alternator is the cuprit of the whinning, you should not hear the noise. If the noise is still there then you have something else causing it.

Make sure you only run this test for a minute or 2 then turn off your engine. Taking off your belt disables the water pump and will cause your engine to overheat if you run it for prolonged periods.

 

Changed the alternator and that fixed the problem. Thanks for your help.

 

Glad to see you got it fixed!