Impala mystery whine killing me

Messages
3
Hello folks,

Long time BTOG reader (Thank you for everything Bob!) but first time post. Hope I can repay the favor if anyone can help.

2011 Impala 3.5 w/103,000 miles 4T65E tranny. Recently I noticed a whine (kinda like a diesel pickup turbo whine, not as loud but getting louder, turns heads) and here are the details:
Not throwing any codes, no idiot lights, happens hot or cold, drive or reverse, whine is only in gear, goes from fairly low pitch at idle to high pitch as RPMs increase (matches RPMs), zero noise in park/neutral at any RPM, zero noise when in park turning steering wheel, zero noise in park compressor on or off, and noise is there in gear with compressor on or off,
no leaks, temperature is perfect, shifts perfectly, runs/drives perfectly, no other noises, trans fluid is at correct level on the stick, just this dang fairly loud whine. Battery was good but low priced 5 year old so I bought new in case noise was alternator, no change in noise. Changed out about 6 quarts of trans fluid with correct full synthetic trans fluid because it didn’t look as good as it should but not bad, (just pumped out and replaced) but no change in noise. One mechanic put a stethoscope on it and said upper idler pulley. I thought it was a stretch (zero noise in neutral/park at any RPM) but I figured it could use a new serpentine belt so I replaced both for shucks and giggles. No luck.
I saw one post that said “No sound in neutral? Does it vary with steering? If it goes away in neutral and isn’t affected by steering, it’s just a noisy transmission oil pump, common issue that doesn’t really hurt anything.” (???) I have now dropped the pan and replaced the transmission fluid filter because I saw that a clogged filter might make the pump whine, no excessive metal on the magnet (almost none), put back a gallon of the old fluid (since it was pretty fresh and I had pumped out B4 dropping pan) and filled the rest of the way to correct level with new correct full synthetic fluid again. No change in noise, still shifts fine. Killing me. I’ll take any wild ideas before taking to tranny shop. Haaallp Paleeeze! Thank you.
 
Messages
1,545
Location
NE Oklahoma
My 4T65E made a whining sound that tracked with engine speed. I can't confirm what it was, but everywhere I read pointed to the thrust bearing. Seeing as the whining doesn't seem to be power steering (no whine when moving the steering wheel) or belt related, this seems like a good possibility.

Edit: Link from Triple Edge Performance regarding Whining Noise
 
Last edited:
Messages
26,163
Location
MA, Mittelfranken.de
Hello folks,

Long time BTOG reader (Thank you for everything Bob!) but first time post. Hope I can repay the favor if anyone can help.

2011 Impala 3.5 w/103,000 miles 4T65E tranny. Recently I noticed a whine (kinda like a diesel pickup turbo whine, not as loud but getting louder, turns heads) and here are the details:
Not throwing any codes, no idiot lights, happens hot or cold, drive or reverse, whine is only in gear, goes from fairly low pitch at idle to high pitch as RPMs increase (matches RPMs), zero noise in park/neutral at any RPM, zero noise when in park turning steering wheel, zero noise in park compressor on or off, and noise is there in gear with compressor on or off,
no leaks, temperature is perfect, shifts perfectly, runs/drives perfectly, no other noises, trans fluid is at correct level on the stick, just this dang fairly loud whine. Battery was good but low priced 5 year old so I bought new in case noise was alternator, no change in noise. Changed out about 6 quarts of trans fluid with correct full synthetic trans fluid because it didn’t look as good as it should but not bad, (just pumped out and replaced) but no change in noise. One mechanic put a stethoscope on it and said upper idler pulley. I thought it was a stretch (zero noise in neutral/park at any RPM) but I figured it could use a new serpentine belt so I replaced both for shucks and giggles. No luck.
I saw one post that said “No sound in neutral? Does it vary with steering? If it goes away in neutral and isn’t affected by steering, it’s just a noisy transmission oil pump, common issue that doesn’t really hurt anything.” (???) I have now dropped the pan and replaced the transmission fluid filter because I saw that a clogged filter might make the pump whine, no excessive metal on the magnet (almost none), put back a gallon of the old fluid (since it was pretty fresh and I had pumped out B4 dropping pan) and filled the rest of the way to correct level with new correct full synthetic fluid again. No change in noise, still shifts fine. Killing me. I’ll take any wild ideas before taking to tranny shop. Haaallp Paleeeze! Thank you.

Power steering pumps on these and a few other GM cars are notorious for whine. Remove the belt and run it for a few seconds I would be willing to bet the noise stops.
Get a new OE pump not a reman under any circumstances.

https://www.rockauto.com/en/moreinfo.php?pk=2164638&cc=1446758&jsn=448
 
Messages
11,761
Location
USA
Welcome to BITOG!

I wouldn't worry about it if it still shifts good. If you live where you have to deal with rust, the car will rust out before you have any real transmission problems
 
Messages
5,683
Location
Fort Worth, Texas
Interesting.....With the trans in gear, With the vehicle stopped......The only spinning components are the Pump & Torque Converter Stator Bearing.

From your description....I'd guess the Stator Bearing is making noise (Inside the Torque Converter). That will need to be fixed right away before it sends aluminum shrapnel throughout your transmission & cooler.
 
Messages
74
Location
Los Gatos, CA
This stuff here rescued an automatic transmission for me one time.


Might be worth a try?
 

Boman

Thread starter
Messages
3
Thanks very much for all the replies y'all. More responses than I have gotten on any Chevy forums! Hate to say but the noise got worse Sunday and included some clicking when coming to a stop and other noises. Then yesterday morning it threw 700 (trans control module) and 741 (mostly torque converter) codes. I gave up and took it to a very well regarded trans shop yesterday afternoon. Unfortunately I believe best case scenario is a new TC and worse case a complete rebuild. Thanks again so much for the replies!
 
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