2008 Tacoma - Odd Noise at Idle / Low RPM

I have a 2WD 2008 Tacoma DCSB SR5 V6 with 68,000 miles. It has made this noise for years. I've taken it to Toyota many times and the mechanics there said they couldn't recreate the sound or situation.

Common variables:

1) Noise occurs intermittently year-round; seems more pronounced in cooler weather.

2) Noise occurs intermittently on cold start-up and occasionally at low RPM. I can increase the tempo of the noise with increasing the RPMs - up to 2,000-ish and then it noise is gone. Sometimes it can be heard again when the RPMs decrease to idle.

3) Noise sounds like a loose pulley but all seems and looks tight. No abnormal wear noticed on moving parts under the hood - pulleys, belts, etc.

4) There are no leaks under the vehicle.

5) There are no issues with performance or acceleration. No warning lights are illuminated.

6) The vehicle has been PM'ed at recommended intervals.

7) I do not tow anything. Never have.

8) I can sometimes feel a slight vibration in the steering wheel and/or gas pedal when noise is occurring. Its very subtle.

https://youtu.be/zKt6UK0mShE

 

I have no idea what the noise is?
I haven’t heard anything similar on mine or others I’ve been around.
I guess the good thing is, since its been making for years, it isn’t “bad”?

Hopefully someone else has some ideas?
I don’t even has a good guess.

 

Manual or auto?

If I got your truck Id remove the belt and park it outside.

If I had to randomly guess I'd say clutch damper spring.

 

Automatic.

 

Why remove the belt and park it outside?

 

Because no pulley or accessory operated by a pulley will be turning.
If you remove the belt, and the mouse goes a way, you know it IS a belt driven accessory.

If the noise is still there, you know it’s NOT a belt driven accessory.

Obviously, you don’t want to run the engine too long.
The cooling fan and water pump will NOT be operational.

Nor will the battery be charging.

 

Makes sense. If it wasn't so intermittently intermittent I'd definitely try it. It may occur every day for a week and then not again for 2 months.

 

Hey OP!

Did you ever figure this out?? My truck is doing the exact same thing.

 

I did not. Still does it randomly - in both warm and cold weather.