Engine rattle/knock under load

2024 SR5 4x4 automatic. Under load around 2500-3k rpm i get a knock/rattle sound. Apon googling and searching in forums I can't find anyone has said anything like I'm experiencing. 2k and Under i cant hear anything but 2500-3 it's noticeable and can't hear anything while it idles. Going to call the dealer later today but was curious if anyone has had this issue or knows what I possibly is? Drove off the lot and haven't noticed it until now at 13k miles.

 

Take it in & get it documented, regardless what they say on the phone....
Dont play games..
I wouldnt waste time even calling, pointless!
They cant diag a noise over the phone & you wont be talking to a tech.
leave it with them, generate a repair order, as long as it takes, as inconvenient as it may be.....

 

I have experienced the same exact thing you are talking about there is several different threads about people experiencing this one of them was started by me lol. I took my 24 SR5 to two dealerships and had them drive it and scan it etc and called Toyota customer service and made a complaint supposedly it’s the direct injectors and the high pressure fuel pump and vacuum pump that sit on the top of the engine

 

I assume me going to them would just result in them saying that. I'm 2500 miles from my next service I'll just say something then.

 

you might get lucky and they dive in deeper just to make sure. I’ve tried different octanes and regardless mine still does it. I actually ordered a hood insulator for my truck that helped a little bit but it’s still noticeable just a little bit quieter. Part number is 53341-AK010

 

You guys have artificial engine sounds turned off, correct?

 

My truck almost never goes over 2k rpm, doesn’t seem to need it with the turbo, can go up a huge hill running at 1700rpm just boosting

 

There's threads about this. Its not common, but not uncommon. Turn ESE off in Carista. That helps some. At least the perceived noise.

 

Have you tried higher octane fuel? On 87 mine sounded like it couldve been a diesel. I find I get the best mileage with 89 and no knock. 93 is faster and no knock but the mpg not as good as 89

 

I've tried 93 and it doesn't change anything. Took to the dealer after a test drive they gave it back to me and service notes said "advise customer these engines can be noisy" and they couldn't find anything. So it'll be what it'll be.

 

I looked in TIS to see if there was anything helpful that might explain this or troubleshoot this. Here's an interesting comment in the information section about the engine:

(a) The Direct injection 4-stroke gasoline engine Superior version (D-4S) system has 2 fuel injection methods. One is the in-cylinder direct injection method that directly injects pressurized fuel into the combustion chamber. The other is the intake port injection method. The ECM determines which fuel injection method to use in accordance with the engine conditions.

(b) When the engine is in the low to middle load range, the direct injection method or port injection method is used, or both methods are used together, to improve fuel economy and achieve low emissions by achieving a homogeneous air-fuel mixture and stable combustion. Also, only the direct injection method is used when the engine is in the high load range. As a result, engine output performance is improved while high compression is achieved by reducing knocking and improving the effect of charging due to cooling the intake.

(c) Directly after a cold engine start, fuel is injected from the direct fuel injector assembly during the compression stroke while the air-fuel mixture in the combustion chamber homogenizes due to the injection of fuel from the port fuel injector assembly. As a result, the air-fuel mixture is stratified around the spark plug to enable a large retarded angle during ignition timing, increase the exhaust gas temperature and quickly warm the catalyst.

(d) 6-hole type high pressure nozzle direct fuel injector assemblies are used to ensure high atomization of the fuel. By using pistons that are shaped to maintain tumble and high tumble ports to promote the mixing of air and fuel and realize high speed combustion, high power and low fuel consumption has been achieved.
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Perhaps that chatter, which I hear with the pedal partly depressed and mostly in eco or normal mode, is in fact the combination of the direct and port injection together. It stops at higher revs, and doesn't happen at lower revs. This is consistent with the explanation above.

 

The truck always sounds ticking they sound like a farm tractor. I just hit 16k km this am

 

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Hmm, so this is what makes the slight knocking noise when cold. I will say Toyota has improved the insulation as we have a 2.5 Camry with the D4S and it sounds like the valve train is coming out of the block when cold.

 

I noticed this too. I listened closely with the hood open and you can hear it coming mostly from the high pressure fuel pump which is mechanically driven. It takes between 10-30 seconds to stop, which I guess is being done to heat the catalyst up to temp. It would be trivial to set up Scangauge or a OBD scanner to read the catalyst bank temps and see the temp cutoff when this stops. I have an older Triumph motorcycle which sounds like a box of anvils and hammers getting thrown down the steps when it runs, so I was a little puzzled at how similar the Toyota engine sounds.

 

It's interesting to hear the difference between the turbo and non turbo 4 cylinders. The Tacoma stops the "knock" much quicker than the Camry. I can only assume the turbo attributes to heating the engine quicker with the oil and coolant lines running through it. I do notice once warm the 2.4T is quieter through a covered drive through than the 3.5 V6 in the 3rd gens.

 

Are there really artificial sounds?

 

Higher trim levels do yes. Luckily my SR5 has none of that BS.

 

So I have the OR package, how do I find out if there are artificial noises

 

Tacoma Gen 4 Engine Sound Enhancement | Tacoma World

 

Mine did. I turned it off with Carista.