Over the past month I have noticed a high pitch whinning noise from the engine. When I accelerate the noise becomes louder and softens when at idle. Similar to engine noise through stereo speakers or a blower sound. I have replaced the alternator and idler pulley thinking it was a bearing. I have also checked for vaccum leaks and cleaned the K&N Air Filter. I have had no major work performed on the engine and this sound is bothering me. Can someone help me out and give me a possible lead.
Thanx

Proud owner of the Beast
1997 F-150 4.6 Liter FI 281 CID VIN W O.H.C.- SOHC
Lariat 4X4 Step-side

 

Fan belt?

 

Johngs

I had replaced the belt friday. When I replaced the belt the sound increased. Tensioner pulley? The noise is heard high in front of the engine.

 

When you replaced the serpentine belt, did you turn the alternator pulley and idler pulley to ensure they rotate freely, and are not rough. Also check the other pulleys.

 

Well its appears to be something thats driven by it.

The alternator pulley sounds like a good idea. I think it might not be a bad idea to remove the belt, and then turn each pulley by hand and see if you can make any noise or feel anything thats harder to turn than it should be.

 

Johngs
Yankee7985

You guys have been the bomb. All the pulleys turn smooth without any binding or noise. I tried the back yard mechanic trick with a screw driver to the water pump. The noise is from the bearing in the water pump. Same sound. Travels through the ear well. I cannot thank you both enough. This forum pays big dividends. Thank you very much. Pricing time.....

Chip