My 2001 Impala 3.8 has has a faint whining from time to time. Yesterday after sitting in a drive-thru line for about 20 minutes it began to whine very loud. As I drove home the whining got louder and my transmission began to shift hard. When I got home I put it in park and increased the rpm by hand using the throttle body. The whining persisted and got higher in pitch as the rpm was raised. This leads me to believe that it isn't the trans. I have had a violent issue every year as it gets cold. I have replaced the radiator, belt tensioner.

My 2001 Impala 3.8 has has a faint whining from time to time. Yesterday after sitting in a drive-thru line for about 20 minutes it began to whine very loud. As I drove home the whining got louder and my transmission began to shift hard. When I got home I put it in park and increased the rpm by hand using the throttle body. The whining persisted and got higher in pitch as the rpm was raised. This leads me to believe that it isn't the trans. I have had a coolant issue every year as it gets cold. I have replaced the radiator, thermostat, all new hoses, and belt tensioner assembly, I put a new coolant level sensor on in it May but it was showing a Low Coolant warning again by October and I am loosing coolant. I traded the coolant sensor in for a new one because that new sensor wound up going bad. When I was refilling the coolant with what had drained while changing the sensor I noticed a decent amount of metal flakes in the coolant. So I'm guessing that the Dex is eating through my intake. The upper and lower intake gaskets have some saturation around them but nothing really leaking unless its on the back side of the engine. The water pump isn't leaking and the whine didn't seem to be resonating from that side of the engine. I couldn't really hear where it was coming from. The head gasket seems to be fine. I bought it three years ago with 81,000 miles and it now has 123,532. I have put some miles on it but it has been adult driven and meticulously maintained. I have had to do quite a bit of work on it but given its age and the fact that it has a 3.8 I think its well worth it. I have been saving to replace everything head gaskets up, but I need to wait until February so that I have enough to replace the actual intake and put and aluminum upper intake instead of replacing it with a plastic one. Could it be that I need to find a way to do it sooner? The upper and lower intake could be fine but I feel like I have a better chance of running across water. The whining isn't exacerbated by turning the steering wheel. The oil is not milky and it isn't smoking. The coolant and trans fluids are changed once a year. Any advice?

Probably the powersteering pump. They have a tendancy to sound like a supercharger when they are going out.

If you can, take the serpentine belt off and start the engine. If the noise is gone, it could be the pump or a pulley.

You can also tell if the power steering pump is going by turning and holding it to the right or left stop (when the vehicle is at a stop of course). When you hit the end of the turning travel the whine from the pump will increase.

I am going to push a different direction, and suggest getting a code scanner on the car to check for codes. The hard shifting is a flag to me. I am wondering if the whine is the transmission pump, because if the car detects long shifts, it will set a code that doesn't light the SES light, and max out the transmission pressure, so that means the pump is working harder, and shifting harder. The transmission pump is always turning with the engine.

If you pull the accessory belt as suggested, the noise would remain.

Thanks so much! I knew there was something I wasn't factoring in. There has been something off about the transmission since I got the car. I of course am going to get a code scanner in on the equation. That sounds more probable given the centrally resonating of the sound. I have put three axles on the car two on the passenger side and one on the drivers. If the pump is over working could it be jarring the axles causing it to put a kinking pressure on the CV boot area? Which is where all three have failed. There has been a minor trans leak more like saturation on the pan. Its not coming from the rear main. I put a oil pan gasket on it in my driveway ( that was fun) and checked it out then. Like I said the trans fluid has been changed every year I have had the car. It had a spell like this once before when I drove it on a five hour trip (the longest distance I have driven it) in heavy rain. The next day it was hot and sunny and I was stuck in traffic. When it did the same thing. Just like yesterday when I was stuck in line. Is the trans getting to hot possibly?

I had to install a new Delco power steering pump and it still whines a bit. I kinda like it as it almost sounds like a supercharger!! ha ha..
With the 3.8 and 4T65E it seems when trans gets real hot, hard shifts becomes the norm eventually.
Get the car scanned and dont be surprised if the dreaded P1811 shows itself. Mine did.
I think the valve bodies, solenoids & accumulator from heat eventually may build up varnish.
What I did firstly was to add a can of Seafoam Trans Tune to trans fluid: Trans Tune - Sea Foam Sales Company
With Trans Tune in took it on a 150 mile highway run & noticed a bit of a shifting improvement.
aprox 750 miles later I dropped the trans pan and used 1000 grit emery cloth to accumulator to bores, installed a the spacers & springs from a Transgo shift kit into the accumulator , and used Dexron VI (6) fluid.
TransGo 4T65E: SK 4T65E

That fixed the hard or harsh shifts & prevent having to remove the valve body /replace solenoids/ Updates etc. All is well now 30k miles later, not one more harsh shift again.

****** Update ******
I drove the car today without the faintest whine. It cranked, sounded, drove, and shifted just fine!?!?!?
It doesn't shift hard normally. Its had an episode once or twice. It over revs from time to time though. It seems to over rev after I have had the battery disconnected. I haven't had time to take off the serpentine belt to see if its the power steering. So I am still led to wonder if the trans isn't getting to hot.

I will have to let other'* chime in on this however, if you are disconnecting battery, the transmission may now go into a re-learn mode where the transmission may have to reset itself and may act a little strange for a while...or is it slipping?
When you say over revs..does that mean it is taking too long to shift into next gear?
Transmission fluid will get hot in normal operation. Pull the dipstick and have a smell of the fluid. As long as it does not smell burnt and the color is still that fresh red look, you should be ok..

It will take to long to shift. Like its slipping. But I have only ever noticed it after having the battery disconnected. That PCS replacement looks like a fun job. Is it the same process pretty much to put the shift kit in? By that I mean should I replace the PCS while I'm in there?

Could I upgrade the trans cooler to avoid this?