I have searched the forums with no luck. I have a whine that is coming from the front right on the engine compartment. It goes up or down with engine rpm. It is NOT dependent on the temp like a lot of the ones I found in past posts seemed to be. It also does not change if I move the steering wheel back and forth. I believe it is my power steering pump but I'm not sure. Any thoughts? Thanks.
2004 F150 5.4l 4X4 75,000

 

It doesn't sound like the power steering pump because the sound doesn't change when you turn the wheel. It could be the alternator if its on that side.

 

Any way to test an alternator or am I stuck taking it to a mechanic?

 

Is the alternator on that side? Check the connections first.
http://www.aa1car.com/library/charging_checks.htm
You could also see what your voltage meter on the dash is doing. If it stays below normal or if it is all over the place, your alternator isn't charging correctly due to a bad connection or the alternator itself.

 

Check your idler pulley bearings on the pulley itself. Same sypmtoms as mine was. Terribly annoying. 25 min job, 20 bucks.

 

I had the same thing with my 04 F150 Fx4. Start it up cold and it would whistle and the tone would change as the sensors caused an rpm change. Occasionally while you're driving as well, and quits with a quick tap of the gas pedal? I was told by Ford it's the alternator, and it's not something that's going to "leave you on the side of the road" .. it is annoying though...

 

There are a couple threads on this problem, from everything I have researched it seemed that most the members came to the conclusion its the alternator whining on a cold start. It happens to my truck but only when its really cold outside for the first mile or two.

 

Thanks for the responses. I'll check the alternator first thing tomorrow. The gauge is not jumping at all but the bearings could be shot. I'll also check the idler pulley bearings as well. Is the pulley replaced as a whole unit?

 

super charger? the factory might have slipped it in there during an oil change?

 

No you can just replace the pulley itself not the entire idler assembly.

 

I don't know if it is the same noise or not but I would notice it on the highway. The good folks here suggested I try a new Alternator, so I did , and the noise went away. Love it when advise gets the job done. FS

 

Just changed the idler pulley on my friends super crew for the noise you are talking about . noise gone

 

I had a terrible alternator whine... So I went out and replaced it with a Napa Gold New Alternator with lifetime replacement and replaced the pulleys. Going great for a couple months then I got the whine back and now a metal-to-metal squeak. Took the belt off and spun the alternator by hand, voila, same metal-to-metal squeak. Good thing I kept the copy of the receipt because I don't want to deal with Ford again on it.

 

I had that happen on an F150 i had before...more than likely it the idler pulley, that is what it was on mine...its cheap and easy to change.

 

instead of starting a new thread....we had alot of rain here a few days ago...and there was some huge *** puddles that i did not go slow threw lol well i think i whipped out my idle pully bearings because i got a whine sound that is like described..goes with rpm not temp related and my batt voltage is a solid 14.4 like it always has been(from gryphon)

anyways... is there any pulley brand i should stay away from...or one i should go with cuz its the best? thanks in advance
Troy