Higher Pitched Engine Noise when Accelerating

Hello all,

My 2020 makes this 'mechanical' higher-pitched noise when accelerating usually starting around 65mph+. The video starts with the noise and I let off the gas every few seconds so you can hear it start up again. Any ideas or just another noisy commonplace 4Runner thing haha.

https://youtu.be/SEOBMbPmDIU

 

Can’t hear anything, but sounds like you’re describing a normal “supercharger” like noise. Also normal, the engine knock you can hear in the video.

 

I think that’s the rear diff howl. My 4runner does it too. Exact same thing. Tacoma’s are notorious for it. 4runners not as much, but it does happen. If you take it in, you’ll likely be told it’s normal.

There are a couple threads on here. I’ll see if I can find them.

 

That's what I was thinking as well, I read up on the Tacoma's reputation for it and thought it might be the case for what I'm hearing. I'm going to take it in to see what they say. Most likely will get the "it's fine" like you said, lol ugh.

 

It definitely makes a high pitch whistle noise (like a dog whistle or when your ears ring) when accelerating at times. This noise was separate from that, though, I wish the audio captured it better!

 

See if you notice a difference going uphill or downhill. I think it has to do with the pinion angle in the differential (whatever that is). And the angle changes on inclines due to suspension movement/weight distribution.

The noise on mine is more pronounced going downhill, but I can still sort of turn the sound on and off by feathering the throttle.

I also went and test drove another 4runner on the lot recently and I could make it make the sound on the highway by getting into the speed zone and playing with the pedal on acceleration.

 

I'm trying to remember if I noticed any change in pitch going uphill or downhill, but it seems to be the same, 75+mph seems to be the sweet spot for hearing it. I took it into the dealer on Thursday, had the service manager drive with me-said he will give me a call Monday to see if he can find any service bulletins on the issue ()- which I found a SB for the 2016-2019's about a diff whine, so I'm going to bring that in and show him, haha. Regardless I'm going to have them take a look at the diff and all the guts that go with it lol.

 

Can you post a pic of the TSB?

 

https://static.nhtsa.gov/odi/tsbs/2019/MC-10154805-9999.pdf

https://static.nhtsa.gov/odi/tsbs/2018/MC-10142876-9999.pdf

This is what I found, may or may not help but worth a shot bringing it up!

 

Very sad, looks like its on the 2020 model also for Daisy; she said its 2020 and I can tell by screen its at least 2020. That's awful buy a new vehicle and have these issues

 

hey 4runningMan, turns out there was metal in the diff fluid, possible replacement of the rear diff on the table. Hope this might help you with yours. I’ll keep you updated!

 

My 2022 has made this noise since I bought it brand new.

 

Did this ever get taken care of?

 

Also, mine is 2wd so front diff is out of the question. Maybe this is just normal?

 

My 2022 has the same noise in the video.. almost like a supercharger whine that is throttle related, not speed related. Pretty weird

 

Good to hear it’s kind of normal. I can hear mine make a slight whining sound with light throttle application between 60-70mph range. Under or over that speed, it’s quiet.

i changed the rear diff oil maybe 10,000 miles ago. Nothing weird about the oil (it was grayish). No change after new oil was put in.

 

Same here.. I probably won’t be keeping this thing very long. Toyota is not what it used to be…

 

I made a post just a bit ago. My 2021 has the howl, my wife’s 2020 does not. I just changed diff fluid and used Archoil 9100. To my suprise and I wasn’t actually looking for it. My howl is gone. I used Redline 75-90 and Archoil 9100.

 

really sad actually, shouldn’t have to do that on a brand new vehicle.

 

I was changing it anyway. Some of them just have some noise. When I grew up in the back of an Aerostar (1988) it had bad rear end noise. It was like that for 15 years. Back then it was normal. I know the fluid never got changed in it’s life.

 

Maybe it is exactly what it used to be… at least in regards to the 4runner. I dont know how long the current diff design has been in use, but I bet it goes way back.

Shortly after I bought my 4runner, I got a long ride in an old 3rd gen 4runner. It was a good 50 miles drive, and that rear diff howled like a banshee the whole way, anytime he touched the throttle…waaAAAA Wow was it loud lol!!! That said, the owner had just driven from Colorado to Wisconsin that very same day, and he wasnt too concerned. Meanwhile, I was wondering when the thing would grenade itself haha.

I may have witnessed what my 4runners might sound like in another 20 years.

Not knocking our taking away from your concern though. I’ve been super particular about my cars when new, and have generally been quite demanding about flaws or other “not quite right” issues. My attitude to any issues on my 4runner is different than other Ive bought. But that’s only because of where I am in life currently, combined with the fact I just really like the vehicle.

 

Wondering what the consensus is on this issue? Our 2020 with 72k is currently in for diagnosis now. We have the Toyota platinum warranty till 100k and hoping to get this taken care of. It is the exact same noise as Daisys video and I just found it this weekend. Slightly disappointing but Toyota has built up
A lot of trust with me so not to concerned about it.

 

The issue of a driveline howl/whine for no particular reason. Not sure if you read the rest of the thread or not? The dealer is currently swapping out my rear diff.

 

Great then, problem solved. Thank you for your input.