I have an '03 5.4 w/ 63,000 miles and the engine has had a whine that has been gradually getting louder over the last few months. It sounds like power steering whine, so last weekend I pumped out a bunch of the fluid from the reservoir and replaced it with new Mercon ATF fluid. Then I drove the truck around, worked the wheel back and forth, then pumped out more and replace it with more fresh fluid. I did this until the fluid looked like new (took about 4 quarts of exchanging the fluid), the old fluid was NASTY and smelled really burnt. It seemed to help a bit, but whithin days it's whining louder than ever. The crazy thing is, when you turn the wheel, the whine does not change. Only with engine RPM.

I took the belt off and started the truck, everything was silent, no whine. I checked some of the pullies and they all seamed fine except the belt tensioner pulley. It did not spin that smooth, felt somewhat rough. So I'll replace that, but the whine I'm hearing does not sound like bearing whine. I've had an idler pulley go bad on an older truck, it did not sound like what I'm hearing here.

Can the pump really be bad? I've never had a power steering pump go bad on any previous vehicle, nor have I ever changed the power steering fluid on a previous vehicle that I've owned. A buddy of mine has a '98 Expy with a 5.4 with 150,000+ miles, never changed the power steering pump fluid and his engine as no whine at all, however piston slap on cold start up is another story.

Is this really the power steering pump? Or is there something else I should be looking at? Thanks for the help fellas!

 

is the fluid at the correct level? my pump isnt quiet at all either and its a reman, i've heard tensioners, idler pullies, and fan clutches sound like my power steering pump does. but i wouldnt really worry about it until you have real problems like steering issues. my old pump was loud as hell and i drove it that way for 10000 miles until someone knocked it off the trash can while i had my motor out and it broke.

 

The fluid is perfectly full, right the the MAX line. I know that Ford is notoriouis for having noiser pumps, but something is not right at all and I'm no willing to just tolerate it.

Are you saying you've had bad pullies whine like a power steering pump type noise? Like I said, my belt tensioner pulley seems to be on its way out.

 

yea i've heard them sound similar, not 100% exactly like the pump but i've also seen people misdiagnose it so i'd replace that first since you already know its about gone.

 

FIXED! Put on a new belt tensioner this morning and the noise is gone. The engine is whisper quiet! I spun the old tensioner pulley and it sounds like metal on metal. It was getting really bad over this past week. Thanks again!