Engine "whine" sound

[Sovrensys]

I have a 2004 Z66 with about 2500 miles on it. There is a "whirring or "whining" sound coming from the engine. It is not the rear end whine I have seen being discussed(I have that too by the way ). It comes from the engine. It changes pitch as the RPM's go up. I thought it might be transmission related as it is most noticable on startup from a stop. But I took it out of gear and revved the engine and it makes the same sound.

Anybody else have this? Any word on the cause before I take it in?

Thanks!

 

[RichUF]

alternator?

there are a whole bunch of different noises going on under my hood, but I guess you are saying that this one is particularly pronounced an annoying

A/C on, off?

 

[BlazerPride]

Sounds similar to a bad serpentine belt.
Or, it's low on power steering fluid.

 

[Sovrensys]

Its with the AC on or off, no difference.

I will check the Power steering fluid, that sounds logical.

 

[spyder63]

Power steering pump may be the culprit. Mine whines on my 2004 avalanche. Sounds louder in the lower gears 1st and 2nd. Never has gotten any worse.

 

[JasonPlace]

I can almost guarntee it is the power steering pump, the dealer replaced 2 alternators on my new AV only 800 miles and then they finally correctly diagnosed it, they put a new power steering pump on my and is quite and normal now. I went through the carlot in Leesburg, VA and you'll be surprised out of the 8 that was on their lot, three of the brand new AV's made the exact same noise. Must be a bad batch of power steering pumps.

 

[BLK03Z71]

I do have this whine in my recently purchased used AV

 

[MOTOX6]

It's probably just the fan. My 04 has a slight not very noticable except to me kinda whine. I do believe it is fan noise.

 

[mister_ed]

I had this exact problem with my brand new Z66 with 350 miles on it last week. The whine started when I was in the middle of a sharp right turn. Thanks to this thread I knew to suspect a power steering pump issue (I have the mechanical know-how of a block of mild cheddar cheese and would have never figured it out myself). Sure enough when I got home I saw a drip, which was the steering fluid. The drip looked pretty bad so I had it towed to the dealer. Ended up that the return hose had detached at the pump (hadn't been properly installed at the factory according to dealer), so they reattached the hose, bled and refilled with fluid and it's good as new, no mas whine. Might be a good first check for anyone else with this problem.

 

[dprg644]

Take it back to the dealer and have them check it out. Let us know what they say/did. Good luck.

 

[JBB3]

I have an '02 Z66 (82k mi) that has a relatively pronounced whine that varies with RPM. Of those in this post that have corrected their problem with power steering pump replacements, did your whine vary with the turn of the steering wheel at all or was it strictly from RPM?
The reason why I ask? Through the years, I have had power steering pumps go bad on other vehicles but it could be diagnosed with the noise pitch change when turning the steering wheel.
I originally thought about the power steering pump as the culprit of my whine problem but dismissed it because turning the steering wheel does not effect the noise. But after ready this post, I am beginning to wonder.

 

[MS03 2500]

Check to see if your belt tensioner is making the noise.

Take the belt off of it and spin it you should not hear anything and it should not be wobbling.

 

[gonfishn]

If you figure out what the problem is exactly could you please post the answer because I have an 03 and it has been doing the same thing. I don't believe it is the tranny because when the truck is out of gear it still does it. The power steering fluid is and has always been full. Someone did mention that there is a pump in the front of the tranny that runs even though the truck is not in gear and he thought it might be that. That is my next step, I know a good tranny guy.....I will also keep you posted.  Thanks