4.6 3v whine

[smokebanshee]

Hello all, I just purchased a high milage (105k) '08 Explorer Limited w/ the 4.6 3v. When I test drove it I noticed a whine that sounded exactly like a PS pump whine coming from the drivers front (pump area) of the engine. I bought the truck so cheap this did not concern me if I had to put a pump on it. Well after investigating further, I do not think it is the pump at all, it seems to be coming from under the drivers front valve cover(front by timing chain/gear). When I put my stethascope on the pump, it is quiet, when I touch the valve cover, it is very loud, and it is only there, nowhere else. I have done alot of research on timing chain, giude, tensioner, phaser noises but none of them match my noise. There is NO tapping, knocking, or metalic noises at all, just a steady whine like a PS pump. I have pulled the belt and checked the two idlers that are in the area and they seem fine. Im stumped, please help!!

 

[vipersinu2]

maybe air conditioner,alternator or idler bearings, try removing the serpentine belt and run truck for 5 to 10 seconds and see if noise is gone.

 

[d.bright]

I second vipers suggestion, run the truck without the belt for a few seconds, if there is no noise, then you know the noise is being caused by an accessory, mostly likely the power steering pump.

I'm also familiar with using a stethoscope, you have two options, use the metal probe, or take the probe off and use the cone part to listen to a wider but still limited range, I suggest using the latter, because a lot of times you wont hear a power steering pump whine using the metal probe.

Let us know how it turns out, I have an '06 making a little whine from the ps pump, I just haven't had a chance to look at it...