Turbo whine from my non-turbo truck

[Pro_Marinero]

I've got a '98 4.0 4x4 with a manual trans. It's got about 140k on it now and I've been slowly doing stuff that is starting to go out. I'm noticing that the truck is starting to whine at around 2500-3000 rpm when I pull gears. It winds up almost like a turbo. It will go away if I continue to accelerate, but gets really noticeable when I float the throttle. I really notice it on the freeway. If I'm in 5th at around 65 holding throttle, the whine is very evident. If I slightly give or release throttle it will stop, but holding throttle keeps it going. It's getting worse and really starting bug me. Any ideas? I'll add it to the growing list (pushrods, axle seals, throwout bearing)...

 

[Dweano]

I wish my non turbo truck sounded like it was spooling up haha. I'm not too sure to what to tell you but is it possible its wind? On one car I drove when I drove the wind would make a similiar sound over the passenger side wiper. It was weird. Yours seem rpm based tho so I'm doubting that. Just a thought

 

[BRUTUS_T_HOG]

transmission bearing, check the fluid and if its full don't worry about it. if you fix it.. it WILL happen again

 

[AllanD]

The only two things I've come across on a ranger that sound
like "turbo whine" were a bad differential pinion bearing.
(sounded like I was flying in a jet helicopter)

And the other was a broken input bearing housing in my T-case

AD

 

[BRUTUS_T_HOG]

what about the whine that 70% of m5od's make in 1st,2nd, 3rd, 5th, and reverse?

 

[99RangerBoss]

could be your intake too! when i put my cold air intake on my old 99 3.0 it sounded like a turbo spooling up at around the same rpm.

 

[whitebassbenny]

crap. my 94 auto 4x4 4.0 is doing that now....

not good?? I have not found what it is to. it's driving me nuts!!

 

[whitebassbenny]

http://www.explorerforum.com/forums//showthread.php?t=244235

hmm makes me wounder what it is now.