Sup all, the last few times I've drivin my truck I noticed a hydraulic whining sound comming from under the hood when starting up/idle. I say hydraulic whining sound because I'm a construction worker and operate many different types of hydraulic powered machinery and it's the same type of hydraulic whine/drone sound you hear sometimes on this type of equipment. It's not super loud, but it's a sound that I know has never been there before and not a normal sound my truck has made prior.

Throttling up seems to have no change on the sound as does turning the wheel - in other words, the sound seems to stay the same regardless what you do. It seems to be mainly apparent when first starting up and idling - sometimes it went away after driving for awhile, sometimes it didn't.

I thought at first it might just be the cold weather but it hasn't done it all winter until recently. I opened the hood to listen to where it was comming from but really could pinpoint it. My dad said he thinks it might be comming from the steering pump area or the bottom right (facing the truck from the front) area of the motor compartment.

Any ideas what this could be? The truck is a 2003 SVT Lightning that just broke over the 8000 mile mark. Thanks.

 

My truck does something similar, especially on cold mornings. When I crank it up and let it idle, and more often, when I put it in gear it makes an "air going through hydraluic valve" whine. It usually lasts only a few seconds. It's been doing that for years and it hasn't hurt it yet. I guess. Yours might not be the same thing, though, cause my sound comes from under my feet. One of these lightning guys will come along soon and give ya some imput.

 

I had a 98 f150 (4.6) and don't remember it ever making this kind of sound and it had 76,000 miles on it when I got rid of it. Unless it's just I didn't care as much about that truck as I do my Lightning to have noticed it, heh.

Another way I can describe the sound is an electric whine like say when the windshield fluid is empty and you held the switch on and could hear the electric motor whining.

 

check the PS pump

 

My friend told me to try some type of power steering fluid additive and that fords where notorious for PS pump whine. Anyone know what he's talking about? Should I use such a thing? I think the warranty if it isn't out, it goes dead really soon. I'll have to call tomorrow and find out what date my warranty expires.

 

My 98 has same whine, ps pump. I pupmed out fluid from res. and added full syn trans fluid, much less noise now.In about a week I will do same thing again.

 

It probably is the power steering pump
mine is loud!
Let me know how that fluid switch works out....thanks

Merv

 

The PS pump is what is making the noise. If still under warranty have the dealer fix it. If not warranteed try turning the wheel from lock to lock ten, fifteen times. Don't hold it against the stops for more than 5 seconds or you will damage the pump. When I play off road, sometimes jumping aerates the steering fluid and causes the whine. This cures it.

JMC