Jake T.

I think the power steering in my 2004 f-150, 5.4L is beginning to fail, but I'm not 100% sure. Here's the symptoms:
It's quiet at idle and at driving speed until traveling a few miles. Then gradually the noise starts to get louder. It sounds like the power steering pump but, turning the wheel side to side doesn't change the intensity of the noise and If I shift into neutral, while at speed, the noise remains at the same level. It doesn't quiet down as the engine r.p.m.'s drop. It begins to quiet down as the truck slows to a stop. Can't get any noise when the truck is stopped even raising the r.p.m.'s. If It made noise when parked I could put a stethascope on it to be sure it's the pump and not an alternator bearing. Anyone have any ideas? The fluid is at the correct level and appears clean. I don't have any steering problems, just noise.

Thanks;

Jake...

ford4wd08

that doesnt sound like power steering to me, its driven by the serpitine belt which will speed up with engine speed and therefore the pump noise should get louder, and in park it should whine too because the engine would still be runnin, maybe it something to do with a wheel bearin or brakes or something....... im not sure, maybe Good old Bill will chime in, he seems to know his stuff

Good old Bill

After reading the thread two times to better understand, had an idea that it was ground speed related. Thanks for the praise Ford4wd08, its seems you had the same idea. Thread starter didn't mention 4X4, so that rules out the vacuum hubs. Untill you can eliminate ground speed as the culprit versus engine speed, I would be looking in that direction.

Jake T.

Sorry, you're right. I didn't mention it was a 4x4. Could that be the problem area? If so, how do I troubleshoot it? The noise sounds exactly like a power steering pump, but doesn't, as I stated, act like the steering pump. I did try switching from 2x to 4x and back again. Didn't detect any change.

Jake...