Rear end noise and engine chatter

Have a 2016 Tacoma Double-cab TRD Offroad.

Since about 8-9 months ago, I've had a noise coming from my rear end. It only happens between 19-21 mph. I've taken the truck in to the dealership over and over and over, but the mechanics initially claimed it was my tires and then they claimed they can't hear it. I had the the rear end gasket redone under warranty (my VIN wasn't listed in the recall, but leaks were found). I've suspected that the two are connected, but the dealership says no. It sounds like I have Curly from the three stooges in the back of my truck- whoo, whoo, whoo, whoo, whoo. Any ideas?

Next up, since I had my 10k service done (current mileage is about 11,750), there is now frequent chatter (like clattering valves) coming from my engine under load. First time I heard it was going up a somewhat steep hill and since then it happens regularly and often when I accelerate. If the trans kicks down quick, I may not hear, but if the trans doesn't kick down or kicks in slowly, then I hear it. Dealership mechanic say it's typical of new cars due to the tuning for better mpg's. I had never heard the noise a single time prior to the 10k service and his explanation sounds like BS. What say you?

 

Does it sound like pinging/knocking from cheap gas? I hear that type of sound more than I have in the past.

 

Are you lifted? Regardless, may be the needle bearing...

As far as the engine, I'd have them reset the Engine Learn, and possibly eleminate bad ECU logic.

 

Does it sound like a metal pinging sound? Only under acceleration? I think I have it too. You usually hear it on high mileage vehicles. I heard it right around 10k.

 

yes, and the mechanic said i might have gotten bad gas. i've since filled up at a couple other gas stations than my usual and used higher octane (92, and non-ethanol 89), but still get the sound.

No lift. I'm planning to bring it in again soon so I'll ask about the Engine Learn. Thanks.

Any idea why we're hearing it at that 10k mark? The sound, to me, is like noisy valves chattering. Only happens for a second or two.

 

I wanna believe it's a mechanical issue rather than a gas issue. Please keep us updated. I wanna solve this asap!

 

After multiple tanks of gas from three different gas stations both ethanol and ethanol-free, i seriously doubt it's a gas issue. And I'm struggling to believe it's normal since I never heard it once prior to the 10k service. I'll update as I have more info.

 

You checked the oil right? If they under-filled it......

 

YOu wrote that it only happens at 20mph or so. What you can try doing is getting a shop that will work with you and that has a high capacity lift. Put your car on the lift and take it to 20mph. Stop if your tires are not balanced and the lift is vibrating. Using a vacuum hose place one in the ear and the other end use to try and pin point the noise.

 

Clattering valves under acceleration and Curly from the 3 Stooges noise in the back seat its time to sell the truck IMO

 

Try to record the engine chatter, post it on YouTube, and share the link. Many here can help but we need more to go on.

 

I've tried different gas stations, also. Mine really sounds like engine knocking or bogging. I used to associate this sound with cheap gas.

 

I did..but now that you wrote that, I'm second guessing myself.

This isn't going to happen. Truck is under warranty, I'm not wasting my time hunting down a friendly mechanic and trying to find the noise with a tube in my ear. And, I'm 99.9% positive the noise is coming from the rear axle. But who knows, if the dealership continues to be of no help, I may be standing under the truck with a tube in my ear...

Nope, ain't gonna happen.

How would I do this? The noise is coming from the motor and I'm in the cab. I can hear it, but there is no way my phone can pick up the noise that far away. Heck, I had a speaker grille that was chafing and I couldn't even record that in the cab!

It definitely sounds like cheap gas. I'm burning through the 3rd tank right now and I bumped up to 92 octane. The noise is slightly less frequent and slightly less noisy. I'm wondering if it's possible that I just needed to burn off all the old, bad gas? ...fingers crossed.

 

Are the problems repeatable enough for a tech to observe and confirm?

 

Yes, the rear end noise is consistent every single time I pass the 19-21mph zone, accelerating or decelerating. And the motor noise has been very consistent, at least enough that they should have no problems replicating. However, each time I've been in with the truck and had a mechanic ride along, I couldn't get the motor to make the noise, and he claimed he can't hear the rear end noise.

 

Do you have stock tires? Which exact truck do you have? Is the truck modded in any way?

 

TRD Off-road, Double Cab. Stock except for tires- BFG A/T2's, stock size.

 

It definitely sounds like cheap gas. I'm burning through the 3rd tank right now and I bumped up to 92 octane. The noise is slightly less frequent and slightly less noisy. I'm wondering if it's possible that I just needed to burn off all the old, bad gas? ...fingers crossed.[/QUOTE]

It will be interesting to see if the problem goes away. It sounds like you may have been hearing detonation. You ECM should have corrected though as you have a knock sensor (could that be a culprit???). You said if lugging up a hill, with no downshift, you heard it. Was is sounding off for more than 1 second?

 

Try rotating tires front to back and see if the problem goes away. Also try turning slightly right and slightly left while the woo woo noise is happening. Let us know what provokes/squelches the woo woo.

 

It will be interesting to see if the problem goes away. It sounds like you may have been hearing detonation. You ECM should have corrected though as you have a knock sensor (could that be a culprit???). You said if lugging up a hill, with no downshift, you heard it. Was is sounding off for more than 1 second?[/QUOTE]

The mechanic at the dealership said that newer cars, in their efforts to get more mpg's, do this now, that it is common. It usually last for about 1-3 seconds max.