Rear end noise and engine chatter

Maybe so. It seems to have lessened recently. Currently on the fourth tank of gas since the potentially bad tank of gas. Been running a different brand from a different station and running 92. May toss in a can of Sea Foam when I get towards the end of my current tank.

 

Anyone have any ideas about the rear end noise?

 

The engine chatter noise is most likely the high pressure fuel pump sitting on top of the engine. It rides the cam, and makes a diesel sounding clatter. Open the hood on your truck and stand on the passenger side, it should be easier to hear from that side. As of now it's perfectly normal, and many people on here will tell you they don't have it, but every new tacoma I have driven makes the same exact clatter sound. Some people hear it and some don't seem to notice.

 

It may be a sub harmonic of the common rear end noise. It is a howl right? If so,

Please record the sound. Hint: take a video, put it on YouTube, and paste a link for us to see. Fold your rear seat down for best results.

 

The noise I'm hearing only happens when I accelerate. I think I know of the sound you're referring to though. Different.

 

Hmm. I'm not sure then. Let me know if you come up with a fix as I would like to know the problem!

 

I can't record it. The ambient noise in the cab typically drowns out the sound I'm referring to when I try.

And not a howl, it's more like Curly from the Three Stooges...whoo, whoo, whoo, whoo, whoo. Between 19-22mph, and more noticeable on deceleration.

 

Will do. It might have been bad gas. But, the dealership head mechanic claims it's normal for new vehicles with auto transmissions. He claimed it has to do with ignition timing and companies efforts to achieve higher mpg's.

 

How about when you do circles to the left or circles to the right, at the speeds you mentioned, in a big parking lot. Does that change anything?

 

We do have roundabouts where I live and I do hear the noise when going through them within the speed range where the noise occurs. Nothing different, all the same.

 

That almost sounds like you have some sort of tire noise.

 

Definitely not tire noise. The dealership said the same, but the noise is strictly between 19-22mph and the sound is from something mechanical, not rubber against asphalt. Tires would make the noise regardless of speed.

 

This is a good hypothesis. Try as set of stock tires/wheels. There may be a resonant interaction with the rear frame and the tire tread/belts.

 

OP, have you tried ethanol free gas? I don't know if it's available in your area, but it may be worth a try if it is. I don't have any input on the rear end noise though.

 

I don't have access to stock tires. My current setup is stock wheels and stock size BFG AT2's. I'm not sure these would cause the noise I'm hearing....

 

Definitely. I have run one tank of ethanol free so far. Then three tanks of other gas, 87 once and two tanks of 92. I'll add Sea Foam later this week most likely, once I'm down to about a 1/4 tank.

 

I am not sure either, but it would be a good troubleshooting next step.

 

*Update*

Took the Tacoma to a different dealership and their mechanic also thinks the rear end noise is due to my tires. Not sure I agree entirely, but willing to accept it for now. Will keep an ear out and see if it changes.

The mechanic also felt that the motor noise was due to bad gas. I'm on my 7th tank since the noise began and ran a bottle of SeaFoam through the last 1/4 tank. The noise is still there, but diminishing and get fewer between episodes.

But now I have new issues...if the truck sits in the sun on a hot day, the driver door window regulator becomes very noisy. Once the truck cools down, the noise goes back to normal. Anyone else experience this?