Rattling noise while accelerating

Detonation is actually pretty difficult to hear with the naked ear. On my race car, I use a detonation can (a mechanics stethoscope that connects to a piece of copper tubing that’s bolted to the engine block) to hear detonation when I’m tuning. Even then, you have to know what you’re listening for...and it sounds more like bacon sizzling/cooking than it does an actual knock. More of a tinging sound

I would be truly surprised if there was enough detonation occurring to hear it in the cabin. I would expect the ECU to retard timing long before the knock gets that loud.

 

What’s Toyota’s recommended Fuel or the 3rd Gen? Can’t be premium, can it?

I’ve heard the 6 Speed autos shift a lot on the highway compared to the 2nd Gen 5 Speed auto.

 

I'm not sure if it's the same rattle or not but I have had a drivetrain rattle since almost new when engine is under load and especially bad when towing.
Took it to the dealership several times with no success.
Finally found the time to get it up in the air and found my issue within about 15 min! I'm not sure if the motor mount is bad or they are just to soft from the factory but the engine is moving so much that the exhaust was hitting the guard on the drivers side, There is a small guard that bends up and over the exhaust and that's where the rattle was coming from, I removed the guard and the rattle went away. I'm still trying to get Toyota to do something about the motor mount. Also found the transmission shift cable has been rubbing on the driveshaft so that is something to look out for as well.
Somehow Toyota logged 23 hours on trying to diagnose and still managed to miss all these things!
Worth a check if you have a rattle when the engine is under load.

 

Just Curious any other updates here?

 

So mine 2018 has under 500 miles and for what I can read it looks like the same issue. I have an appointment on Oct1st to see what they diagnose. I do agree going up a hill seems to trigger the issue a lot faster. I will try with higher octane gas and see if it helps.
I noticed when the AC Fan is off it will make the rattling fore frequently than when the fan is on.

 

That doesnt sound good. Sound almost like something is loose...and shaking when you give it gas kinda.

 

Stop filling up at johnny's cheap O gas and hit the Shell.

 

That doesn't sound like pinging.

 

I hope is just the gas. I will fill up with premium and see if it helps. It doesn’t make the noise everytime. I will fill up and update the forum.

 

Did you ever get this fixed? My truck is making the exact same noise.

 

any update

My 2020 does this too when acclerating uphill.
my 2013 taco never did that

 

Does yours sound like this? I've recently noticed that it only does it if the ambient temp is above 60F. The warmer the outside temp the more it makes the noise. I've yet to take mine in as the weather here has not been above 60-65 consistently and I want to make 100% sure the dealer is able to reproduce the noise and not feed me the "can't replicate" or "normal operation" bs.

https://youtu.be/MHPLn7YAViM

 

28? Jebus I get like 14-16 city and about 20-22 highway on 93 2.0 19800 performance gearlock tune. I have noticed, people make MPG claims without stating their altitude and terrain. Someone in a hillfest area is going to get WAY worse mileage than someone who lives in say....Florida where its flat as a board and at sea level.

 

Hey! I’m new here and mine does exactly same annoying noise, it is a pretty new Tacoma 2019
SR and the dealer told “can’t reproduce the noise” ( I’ve shown video and nothing), so I have been researching since then and has some long time it doesn’t happen in my truck when I’ve begun to use Shell 89 grade. It happened when loading around 2500 to 3000rpm with A/C on max. I’m almost sure it is really pre-ignition problem because, as you said, in warm conditions and, in my case with A/C on, increasing the the engine load and consequently the its temperature, the perfect condition for pre-ignition. With a better gas looks it’s much better.

 

Does yours sound like it's coming from behind the radio or from the two center vents? I have ran different grades of gas and still have the noise.

 

This may have been mentioned already, but I didnt read every page. In my experience with tuning sports cars, vehicles come EXTREMELY lean from the factory for EPA MPG requirements. The hotter it is outside the higher octane is required as it causes predetonation. Latest sports car, my FoRS runs on an E30 tune, which in winter is at 30, but during the summer I have to keep it closer to 40. Running 87 like a cheapass on a brand new car off the lot these days is borderline dangerous for the engine as they can ping even on a mild day driving up an incline, or during towing. It comes in a variety of noises and indications. I've had the same issues with every new sports car I've ever bought until I tuned it. You wont get better mileage but you will see better power delivery, drivability and it will put the engine in it's intended operating range without the strangling grip of the environmental protection agency around its throat. This will increase its life expectancy, given your not "racing it" around. And it's not some super agressive tune which I think goes without saying. My recommendation would ether start putting higher octane fuel in it, or have it tuned properly.

 

Yes, looks from the radio direction, and at first I was wondering the noise came up in the dashboard.

How I didn’t get the noise anymore, I will try the regular grade again to save some money... but I will keep Shell for awhile.

I tried to upload my video but it doesn’t workout... it is pretty same yours.

 

Great information!!! To be honest I didn’t know about tune the gas with ethanol.

So, when do you say e30, does it mean 30% of ethanol in the gas? I need to research what should be the best for my 2.7l engine.

Thanks for share!

 

Yes e30 is 30%. I wouldnt recommend an ethanol blend for the truck as that's primarily for excessive high performance applications. And you need about 20% more ethanol to do the same work as gasoline so its extremely inefficient. But the benifit is that it burns "cooler" and allows for timing adjustments before pre ignition occurs, so it's kinda the same effect as increasing the octane but with the added cooling. Ethanol usually requires a fuel setup that can deliver the increased flow rate since it uses so much more fuel, and can be hard on the system. Increasing the octane rating just means the gas is more resistant to predetonation under higher compression. That's why most sports cars require it, it's not just for "more HP" it's because if you run 87 in your Corvette it will ping like crazy, especially high compression or forced induction engines. Leaning the engine is a artificial way to cause det, as it all comes down to stoichiometric ratio, and that changes based on temp, load, and fuel type. The engines stock ECU usually isnt able to pull enough degrees of timing to handle a heavy load, high temp situation when its tuned so lean, and by lean it means less fuel. Your ignition timing is always being adjusted on the fly but factory tunes usually have them locked down to a pretty narrow band. They dont particularly care if it damages the engine in the long run if it passes emissions standards, since the automotive industry makes most of their money on service of vehicles not sales. In your case you would just need to run a higher octane fuel like 91 or 93. They have 10% ethanol already.

 

Thanks VoodooPro for all the explanations. So, I will keep the higher grade because it looks to work to me.