Squealing Noise

I recently purchased a 99 Tahoe. It runs great, passed smog no problem. However, I noticed that when I drive faster than 65 MPH, I begin to hear a squealing noise that appears to be coming from the rear. Its not a real loud squeal, but enough to hear it when I have the radio on. Just about the moment the speed drops below 65 it goes away (or at least dies down to a level I can't hear). I've sped up then let my foot off the gas and it'll squeal until the speed drops below 65. At idle, if I get out, I can hear a similar noise coming from the driver side rear wheel well. Possibly the fuel pump? Also, when I turn the key on, but not start the motor, I'll hear the noise for about a second; when I turn the key off, I'll hear it again for about a second. Any suggestions?

Did you ever get a reply from anyone or get the truck fixed?
I currently have developed the same exact noise. I was told it was probably the fuel pump going out, but then told that the fuel filter might be the issue since the pump has not stopped working completely and the problem with stalling is random.
Let me know if you found out anything.

Did you ever get a reply from anyone or get the truck fixed?
I currently have developed the same exact noise. I was told it was probably the fuel pump going out, but then told that the fuel filter might be the issue since the pump has not stopped working completely and the problem with stalling is random.
Let me know if you found out anything.

Haven't figured it out yet. I'm leaning towards it being the fuel pump, but I'm not having any random stalling issues, which makes me think twice about that. I never thought about the fuel filter but that is a possiblity too. Anyone else have an idea?

I would rule the fuel pump out, mines went out & the truck never made any noises. When ur pump goes out, your truck goes on a flatbed, so I would check elsewhere. I could be wrong, that was just my experience.

If you hear a quick noise, coming from around the left rear wheel well when you turn your key on, that is the fuel pump. And they do get louder as the get older. I have a 99 Tahoe with 107K. The fuel pump got very loud before it finally went. When I put the new one it, I thought it wasn't working for a second as I could just barely hear it! Cousin's Z71 did the same thing.

I never did hear it at loud speeds, but I have an exhaust system on the truck, so most likely wouldn't.

My truck never did the start/stall thing. In the 63,000 miles I owned the truck, twice, time frame very spread out, it just wouldn't start. Went back a few hours later and it was fine.

I finally choose to replace it when it wouldn't start and I had to bang on the gas tank to get it started. I wouldn't replace it until you have to, but if you do, let me know, as I did mine myself and can give you some tips. But, if one day it just won't start, have some one turn it over while banging on your gas tank.

BTW- shop down the street had 2 chevy's in from a business about 1 year ago. Had to bang on the gas tanks to get the going, and they have been fine ever since. Never did replace them.

Thanks for the responses, gentlemen.
I agree that the fuel pump simply goes out...period...and the flat-bed truck gets it to the shop at that point.
I replaced the fuel filter last night and thought it was running smoother until I noticed at lunch just now that it was still idling rougher than it should. ???
I can still hear the fuel pump come on and go off when I turn the ignition on before cranking the engine, but not every time. If the engine is cold I don't hear it. After the engine has run for several minutes it starts to get loud enough to hear. Also, right after I cut the engine I can hear the fuel pump "turning off".
So, could there be something in the gas tank that blocks the intake filter on the pump inside the tank which would make the pump labor to take in gas thus causing it to make a louder than normal noise? Or is it simply getting old, as suggested? Could the fuel relay be the issue?
Any words of wisdom are appreciated.