Hey fellas. I have a 2005 STX with the 4.6L, 4WD, AT.

The engine has started to make a loud whining sound recently. I replaced the belt and tensioner since it was original and had 93,000 miles on it. The sound is still there.

The sound increases with rpm but doesn't change when you turn the steering wheel.

The engine starts and runs smoothly with plenty of power.

Any ideas?

 

All the time, or just for several minutes when it's cold? If the latter it may be an alternator bearing issue. Mine does that when it's cold out... I'm not going to do anything unless it craps out. The noise goes away as soon as it warms up a little.

 

It's a continuous whine, from start up till I shut it off. It doesn't get louder or quieter but does get faster with engine speed.

It sounds similar to an old hand cranked siren.

 

I recently had the same thing and it was my idler pulley bearing that was bad. Quick fix, but the bearing was VERY bad.

 

Thanks Gizmo.

Do you remember how much it cost?

 

Depends on who you trust for parts, etc...but IIRC mine was somewhere around $20 or something...Here's what I found on O'Reilly:

Dorman TechChoice 419-602 - Idler Pulley | O'Reilly Auto Parts


It took me about...oh...10 minutes from start to finish to replace it with an extra pair of hands from my Dad to help with the belt.

 

Thanks again.

 

Not a problem Hopefully that's all it is and it's an easy fix for ya!

 

^^That would be my next guess (and cheaper to fix). We're almost neighbors... I'm in the other bottom corner- Coffee Co.

 

My truck does the same thing - the whine is only present when it is about 35 degrees or colder. Had it last winter, went away all spring and summer, and just started back up again the past few weeks.

I think it is a vacuum leak. Because the truck runs fine I haven't bothered to investigate further.

 

Thanks fellas.

I'm going to try to replace it tomorrow before the SEC championship game kicks off.

I'll let y'all know how it works out.

DBR, are you a Roll Tide or a War Eagle?

 

The idler pulley on the driver's side was bad. Easy fix with a third hand. Thanks.

While investigating the problem and repair I noticed the idler pulley on passenger side had only a minor amount of wear and the belt doesn't fit tightly against it. Is this normal?

 

The belt might have an odd shape in it now if the driver's side pulley was out of balance for a while. Might not hurt to replace that as well..

 

I will eventually. Right now I'm just enjoying the quite so to speak.

 

...Actually a Vanderbilt Commodores fan until my nephew graduates. He's their punter.