2022 Manual Trans Rattle Sound

The ADM thread talks about the noise from the heat shield. I suggest throwing some sound deadening mat on the heat shield and see if it goes away. Or, for a test, take the heat shield off and see if it stops.

BTW, mine makes the sound too

 

I'll take those noises haha, as they're consistent, so it's easy to pass them off as "normal". And I love your GIF profile picture hahaha! Sending it to my Jeep buddy now.

 

This hardly constitutes a controlled experiment, but I have treated my Tacoma to Fluid Film twice now, and the diff whine, while still present, is much quieter than when the truck was new. It has 15k miles now. The Fluid Film coating picks up dirt and small rocks and forms a thick paste over everything, including the leaf springs and frame. I have also changed the diff lube to

$28 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90, but that was after the diff quieted down. It's still there, but it's nowhere near what it was when I first got the truck.

 

Well, I might have spoken too soon about it not being detonation, because it happens only when the engine is fully warmed (A/C on, summer afternoon, etc.). It is more pronounced on 87-octane fuel. I have been unable to replicate it in the morning, and the noise seems quieter and harder to induce (more throttle required) on my current tank of 89 octane.

I suspect it has to do with their transitioning back into Atkinson using the port injection from a high-load, primarily D.I. Otto cycle mode during high ambient temperature. Some ideas:

* The throttle opens for Atkinson mode slightly ahead of the valve timing shift, resulting in a transient lean condition.
* EGR opens for part-load but takes too long to have an effect, briefly increasing knocking tendency.
* Cylinders have hot spots when coming off high load.

Take these with a grain of salt; my ECU development and tuning experience has been only with diesels, and I have no technical information on this engine.

I may try a full tank of 93 to see whether the noise goes away completely. That would confirm whether it's knock versus something external, like a heat shield.

W.

 

I am dealing with the dealership right now over the same issue. So annoying and sounds like a beater truck while driving down an FSR

Did you ever get yours fixed?

 

mine rattles just like in the video on post #12.

i also have another rattle that comes from the rear wheel well liners, both sides. i can tap on the side of the bed and it rattles and makes noise. i have been meaning to secure the liners but haven't got around to it yet. when i am done it'll match the access cab door panels that have gorilla tape around the perimeter to keep them from rattling. pos.

 

Fluid Film has quieted by diff whine, as well.

 

After a top-up with 93 today, the knock when backing off the throttle has been drastically reduced, barely audible only when the windows are down. This confirms to me that it is sensitive to octane. The question is then what to do about it, if anything.

 

I get that, too, so I keep it in gear as long as possible. It doesn't bother me.

 

Hi All, I'm bumping this thread, as I've had time to do some sound recordings of my Truck. Listen to my recording here:
https://www.youtube.com/watch?v=JaUDj5WI1fA

When comparing to the sound of Sinister184's post above (Dated April 13, 2023 at 8:22 PM), which I've also linked here for easy access, the frequency of the sound is identical. Whatever is rattling in his truck is rattling in mine.
Sinister184's video:
https://youtu.be/jAaTsq9EczE


It rattles when:
1) I go over bumps (like he is in his video)
2) When accelerating & letting off under load in most gears around 1500-2000 RPM.

I've looked at other forums regarding this issue, but have yet to find something concrete.

Can anyone confirm:
1. The source of the sound, and why it's occurring?
2. The Solution (Is Toyota aware? Are there any TSBs regarding it? I've only seen the one for the 3rd gear issue in the ATs)

 

I used to get odd looks due to the noises that came out from under my 21. Kinda embarrassing really. Had something to do with the shifter linkages and did it since new so I just

 

#1 is from somewhere in the driveline. Mine has done that in neutral since Day 1. It comes from somewhere between the center to rear of the truck. It has never bothered me.

#2 is engine knocking. I believe it has to do with the transition back to Atkinson mode after the engine has been under a moderate to heavy load. In my experience it's 1500-2800 rpm and especially around 2000. Higher octane fuel reduces it significantly. I have tried recording the noise with a phone but haven't been able to capture it without it getting drowned out by wind noise. Try 88-89 octane.

 

I think (my experience) it's a loose around exhaust heat shields hardware or broken weldings. Check heat shields, I'm pretty sure it's your reason!

 

I'll try and wiggle some things around and see if I can figure it out. I think you're right about the driveline. The clunk sounds too heavy to be a heatshield.. perhaps something on the driveline is making contact with a heatshield when going over bumps?

Thanks whiseve, I actually went back and read your posts from last year on this thread. Today, I had a half tank of 87, and filled the remaining half with 93. This has significantly reduced the knocking sound. I'm curious as to what a full tank of 93 will sound like.

Could running 93 do any harm to the engine (like not being tuned for it)? If not, I'll plan on running 93 instead if it's better for the truck in the long run.

 

No harm to anything but your wallet.

 

It’s due to the design of the manual transmission in this truck. It’s because the countershaft is tied to the output as opposed to the input which means it’s always driven by the road/wheels turning. Every transmission I’ve driven of this style does this, including my old Nissan frontier. Every transmission I’ve driven that is not set up this way, such as my Jeep, and Toyota 5 speeds, do not do this.

It is not a problem, and the reason the noise never changes or gets worse is because it is simply a product of the design and there is nothing to improve or get worse. It will always be there as long as you are going over bumps in neutral.

 

After running 89 for some weeks, the rattling seems to be about the same as it was when running 87. Have you noticed this? I’m wondering if either 1) the initial reduction in piston slap was placebo, or 2) the piston slap did go away temporarily, then the ECU recalibrated/compensated

 

Thank you for this explanation! This makes perfect sense. The source of these sounds has been darn-near impossible to google, yet the explanation is so simple.

Do you also have the piston slap sound around 1,500-2,000 RPM like some of us are experiencing?

Does anyone know if this will eventually resolve itself? Or will it eventually lead to a big engine tear-down later on?