kate

2002 ES 300 62,000mi.
I have noticed a strange noise that appears at a constant speed of about 60-65 mi/hr or higher. It's hard to describe the noise; it's not loud and almost unnoticable. It seems to be related to higher RPMs (?). When accelerator pedal is pushed, the noise stays on, when I let go of the pedal the noise gradually subsides. What can it be?

Thanks

Tammy

I'll give this a try.

Have you tried to duplicate the "noise" at a slower speed. Meaning shifting out of overdrive or into second gear, driving the auto to the failing RPM and the noise occurs? This will determine is it chassis related or engine speed related.
You are going to need to reference the noise to something common.... Metal scraping , tire vibration rumbling, belt squeeking, even a mild hum. "It is not loud and almost unnoticeable" is what it's not, then what is it?

I would suspect it is tire noise. Have your tires been rebalanced and rotated? ... You failed to mention the age of the tires and if they are worn uneven. Are you checking your tire pressures? Additionally, have your suspension bushings, steering, rear suspension and ball joints checked for wear; this may cause vibrations.

kate

Tires are 2 months old. I thought of that; but if it was tires, the noise would stay if the accelerator pedal is not pressed and going at the same speed. It seems like when the RPM is dropping, the noise subsides gradually. When the cruise control is on- noise is still there. It does sound similar to tire noise, kind of like rustling, but it's not tires.
If I tried to reference it to something common: I think it kind of sounds a little bit like crickets (insect crickets), or like some small plastic part is loose and is spinning very fast (?), or like a very rapid quiet rattle (not sure about this one).... I am out of ideas...I think there is also a high pitched whine to it, but it's not loud;
I don't think it causes any vibration, if it does, it's hardly noticable.
Could it be something transmission related? I will try shifting gears like you said.
What could it be if it's engine speed related?

PS: I just thought of another description: very rapid ticking.

Tammy

If possible, check out the belts and power steering pump/alternator with the right front wheel removed. If the belts are original, this could very well be your problem.

Only if your comfortable, I would take a long flat screwdriver and Carefully press the end against the power steering pump and alternator and listen to the handle end.... With the belts running in your face. If the unit has a bad bearing, the sound will travel the screwdriver length and allow you to hear the bearing squeel over the engine noise. You can use the same technique anywhere on the engine, just watch for moving parts !

As to the transmission, is the fluid somewhat fresh and cherry red, or redish brown / black? Hopefully, the transmission is not at fault... drain and fills are pretty simple maintenance.

Pheonix

It can be number of a thousand things on the car that rotates & you've given us little good information to help you with.


What Tammy said.
Check the belts, stick your head in the bay & triangulate the noise, then go get an alignment done if it's not the engine.

kate

Thank you.