Whine from front of vehicle when at operating temp

[slowdime]

So I've had a 2002 Cavalier for a couple weeks now. Changed the oil, the ATF looks ok, coolant needs a change, brake fluid looks ok, PS fluid could use a change but isn't horrible. I've noticed once the car is at operating temperature there is an audible whine. It isn't terrible loud but it is noticeable. The pitch varies with the engine speed, but only while in drive. I've put it in neutral and park and revved it and the whine doesn't occur then. I've shifted to neutral while going down hills and the whine 'spools down' as the engine drops to idle speed. I haven't tried revving it while rolling in neutral. I was thinking maybe water pump but I would think it wouldn't matter if it was in gear or not. Any ideas? It drives and shifts fine.

 

[Oro_O]

I have a vehicle with a GM transmission (4L30E) from that era that did just this. They are related units, though not identical. I added some Transtune to the AT, ran it a bit per the instructions. Drained/flushed and replaced with new fluid. This was at 12yrs old/140k miles. 20k miles later it is incredibly smooth.

If you have a dipstick (do you?), then you know it's not low on fluid. Correct? Mine is "sealed" so had to go exploring underneath. I'd wager the fluid is shot, or possibly low. Valvoline MaxLife is a great ATF; I'd get some in there.

 

[slowdime]

Yeah there isn't a dipstick. There's a small fill port with a red plug on it and a plug down below to check the level. The fluid looks ok from what I can tell. I suppose it couldn't hurt to drop the pan though. I've got a bunch of atf for another vehicle laying around as luck would have it. Did you actually flush it or just drop the pan then fill it?

 

[Oro_O]

Looking back at my notes, on that vehicle what I did was actually drop/clean/fill late fall. That made a big difference, then I did a 2nd drain/fill the next summer.

If you checked the fluid, I believe that needs to be done with the vehicle running, possibly in gear (need to check instructions for the unit). If you pulled the check plug with the engine off, it could appear more full than it would be w/the pump running.

I used a fluid transfer pump and it was a real PITA. I helped a friend recently and we took 10' of 3/8" ID tubing, stuck it in the fill port on his Toyota, then stood up and filled it holding the top at about window level. Gravity feeds it in and it's a lot easier than the pesky little pumps.

I doubt that vehicle has an aux cooler built in the transmission? if so, save yourself the hassle and do all the fluid at once via those lines. Then you won't have to go back to re-do the messy, awkward job again soon. If so you can google how to do that, lots of DIY videos and posts on auto forums. Not hard.

 

[slowdime]

I'll have to look into it. No owners manual came with the car but I'm sure I can find one online somewhere. I've got a small hand pump but they are a pain, I've filled a few differentials using some tubing, much faster and easier. This is the first vehicle with an auto trans I've owned, they just seem so fragile to me so I've avoided them in the past. Plus shifting gears when I want makes driving more fun. An auto trans just makes a car feel like an appliance IMO

 

[Mud]

I suggest to change the PS fluid, don't go just by looks, this sort of sounds like noise from the PS pump.