Whine during acceleration update: finally got it on video!

Setting up another service with my local dealer.
All previous attempts the dealer says they can't reproduce and that whatever I was hearing was probably normal.

But this time I finally got it on video!
First heard at 200 miles, now I have 2500 miles.

https://youtu.be/JWkM7mKBy0s

 

Wow, if i didn't know any better it sounds just like one of the work vans going down the highway when we had nothing put on the roof racks.

 

That's an AC expansion valve resonance. Another 3rd gen design quirk.

Usually occurs with engine at 1500-2500 rpm, high heat load on the evaporator, and lasts about 3-4 seconds after the compressor engages. There's nothing the dealer can do about it since it's a design problem, not a part failure.

I sometimes find it goes away or is lessened if you switch to recirculated air and let the cab cool down a bit since the heat load on the evaporator would be lower.

 

That's might be it. Sounds like it's under me though, and I'm fairly certain it's done it with the AC off.

 

No roof rack, stock SR.

 

+1 for air conditioner. You hear it really well at idle on a hot day sitting in the drivethru.

 

Hmm ok ill still get it checked out but ill buy its the ac. This isn't my first 3rd gen taco, but maybe its the first one I've noticed it in.

 

It's the extra secret supercharger they hid in the AC

 

I recall seeing a thread on here from a while ago where someone was chasing down a phantom whistle. It turned out to be some holes on the bottom of the lower control arms whistling. Probably a long shot but crawl under there and throw some duct tape over them and see what happens.

 

Sounds like my AC.

 

I've had my ac on on hot days here. Truck never made any noise as such. How long does it need to be on to make that noise?

 

I don't know I've never timed it.

 

I have that same sound, been driving me crazy thinking something was wrong.
I can say that I have never heard it with the A/C off, so that make sense now.

 

https://www.sae.org/publications/technical-papers/content/2015-01-2275/

It’s a common thing apparently. I had some repair work done that required them to disconnect the AC system for the repair so they drained the system and refilled it. It stopped after that so I don’t know if it’s got to do with exactly how much charge they put in or what. AC doesn’t seem to kick as strong as it used to though

 

I am the only one that thinks rear diff whine? Audio could be weird but that’s how mine sound.

 

Diff whine is very similar sound, but he's not going fast enough in the video. It also cuts out.

 

My 2020 does it and so did my 2006. It's the AC whistling. It's happy and likes to sing. As stated above, it's normal.

 

For some additional context I was accelerating from 0 to 45 in the video.

Whistle happens between 3000 and 4000 rpm and only happens during an acceleration event. Never at a stand still and never during deceleration.

 

Rear end whine is typically at 60mph.

I heard you whistling immediately after a shift, and that was definitely the A/C, but not before.

Perhaps I'm not hearing what you're hearing then.

 

Yes typically happens during a shift. would have not quessed that, was convinced it was drive train.