Got a 08, 5.2L V8 with 32,000 miles. The engine has developed a whining noise, much like when power steering is low on fluid but it's not the PS. It has something to do with the engine because I can recreate it when stopped, in park. It fluctuate when the engine is revved up. I have checked all my fluids. Thinking maybe a pulley or fan belt????

 

Take your belt off the tensioner and check the grooved idler pulley and smooth idler pulley. Pretty common problem. Most likely it is the grooved pulley though.

 

Jeff...thanks for the info. What exactly would I be looking for, excessive wear and tear?

 

FYI its 5.4 not 5.2 lol

 

tampajim did you solve your problem? I currently have the same problem. I suspected it was either the idler or a bearing in the altenator.

How to tell which idler it is?

 

Hello please write up if you solved the problem, As I seem to have the same problem.
My mechanic thinks it the A/C clutch bearings going out, could it be? Whining noise appears only when I rev the engine, even in park. 2004 5.4

 

Oh I hope its not that. I just changed the idler pulley (grooved) and still have the whine. I tried spinning all without the belt on and it appears the smooth pulley above the tensioner did not want to spin easily. I am going to change this tomorrow and see.

 

I just changed the belt tensioner pulley and problem solved. It is on the back of the tensioner arm. 3 bolts to take off the entire arm.

I would suggest to anyone else to try these pulleys first. They are easy to take off and cheap to replace.

 

I had the whine, changed my belt tensioner and it solved about 75% of it. The remaining 25% is my power steering pump that need changed soon.

 

Alright thanks to everyone who responded, great info here. I solved the whine it was in fact the belt tensioner. sounds like a brand new truck again