need some help experts!!

[Dark_knight]

vehicle: 1999 expedition xlt 4.6l (triton) 4x2

This issue has been going on for about 5 months now...

on start-up from cold start, you can hear a whinning noise (slight) until engine idle settles (about 2 sec.)

when driving, the whinning is constant and gets louder the harder the gas is pressed. when cruising highway, there is a constant whine, again the more gas, the louder it gets. when coasting (off throtle) the whinning seems to go away.

recently i have put the truck in nuetral and rev. when i do this, this whining is gone, even while reving, but as soon as i put in drive, the noise is there.

What i have checked:
tranny fluid level is perfect (could use flush and filter) will be doing this within the month
power steering fluid on mid mark(between min/max)
sprayed penetrating lube on each pulley with no luck.


i havnt went into to much work with it as it has been the spare vehicle, but i am leaning towards "power steering moan"..

hopefully someone has ran across this problem and has found the solution before i start diagnosing....

 

[Lifesavr65]

I changed my PCV valve with a metal one and had similar issue. Installed OEM and it went away.....

 

[docraymund]

It might not be the power steering because noise from the former only occurs or is noticable when turning the wheel while stationary. It could be a problem with your transmission.

 

[srs7324]

My 99 started whinning right after I washed it one night in a auto wash.
I checked everything twice that you would suspect, I still could not find out where it was coming from. Of course mechanics could not diagnose unless I left it with them for the weekend and I was noting doing that for only a noise.

I noticed it was coming from the front of the engine but it was not coming from underneath so I very carfully laid my hand on every part while the engine was running.


The alternator bearing was going bad, and at low RPMs it would rattle the complete engine. I replaced it and I have been noise free ever since.

 

[RobertNol]

I had the exact same problem. Checked the pan and it was filled with a bunch of flakes. It was the filter getting clogged and it was the transmission pump squealing. Changed filter and fluid and it ran perfect but had to change it every 3000 miles. It lasted for another 67,000 miles and lost R,1,o/d on a 500 mile trip to g.a. and back.