Engine squeak @ a certain RPM speed

[GreenSlave]

I have a 2000 Explorer sport 4.0L OHV. The engine sqeaks(nothing to do with belt), could have something to do with the power steering. It squeaks @ a certain RPM speed, while I'm in drive and at a stop. The squeak stops if I put it in neutral or if I do something to shift the RPM speed from the "hotspot" such as putting the windows down etc. There are no leaks and the power steering reservoir is at the proper level. When I move the steering wheel left and right the noise is still there. The power steering was just a guess, could it be something else?

 

[airwolf]

It really could be anything. I had a couple trucks that the alternator would do that. Not saying that is it, but it might just as likely as the powersteering.

 

[aldive]

How did you rule out the serpintine belt? Have you considered the belt tensioner or idler pully?

 

[GreenSlave]

I just had the belt replaced and it sounds like the noise is come from the rear of the engine. It's hard to tell where from but it's definetly not from the area around the belt.

 

[pj8847]

As stated, it could be anything. First thing to do would be to pinpoint where the squeak seems to come from ( front of engine, back of engine, top or bottom, left or right side respective to front or back and so forth )

Being that you have the OHV, you can rule out cam bearings, but, if its from the front, it could be alternator, water pump, power steering, idler pulley, tensioner pulley, even the AC compressor, or clutch assembly, even the IAC valve, etc...

If it is coming from the back, could be the CMP drive unit, possibly something even resonating up from the torque converter, etc...

My 95 Ex. with a new 4.0L OHV used to have a squeak at or just a hair above idle, on cold days it would be worse then on warm, and after locating roughly where the sound was coming from, ( the back, but sounded like it was inside the intake manifold ) I was able to find it with some investigation, and it turned out to be the CMP drive unit. So I removed the sensor off of the drive unit ( 2 screws ) and hit the drive with first WD-40, and then dried it up and hit it with some White lithium grease spray, wiped off the excess and put the sensor back on. No squeak ever since.