PCV Valve weird noise !

Take it back!!!

 

Any dash lights displayed?

I'd check the area around the PCV for damage as sometimes when the valve gets replaced, the cover gets cracked.

Wouldn't be the first time that has happened .

But a trip back to the mechanic would allow for a better diagnosis.

Good luck and keep us posted.

 

So...the throttle body butterfly is positioned by a small electric motor and it's position is measured by a sensor. The motor positions the throttle body based on the ecu signal and feedback from the position sensor. At idle, the ecu is looking for an rpm. This is one of those things that is a 'learned' position. As the throttle body gets dirty, etc, the position it returns to for idle will gradually change. If the throttle body gets cleaned, and the butterfly goes to its current learned position in the ecu memory, it may be open further than needed and rpm will be higher. Over several cycles, the ecu will 'learn' updated positions and will start positioning the throttle body correctly.

After doing a TB/MAF sensor cleaning, disconnecting the 12v battery for a moment will reset the ecu's to their default values and the 'learned' values are no longer used. It should now match more closely to what the car needs.

This is also why people run into trouble sometimes after disconnecting the 12v battery. All the ecus go to default values, including all the 'learned' values. If your throttle body is dirty, but now the ecu has returned to default, it may not be in a good position for starting the car and codes out.

 

No, you don't have to take it back. Just disconnect the 12 V battery for 15 secs, if it is not behaving. Refer to
TMR-JWAP's post #4, which corroborates what your mechanic said:

and is right on the money, although, I don't know why your mechanic did not just disconnect the 12 V and save you all the angst.

 

so whats next step if TB buzzing sound does not go away... its been 2 months... lots of miles. 2004 184k. never buzzed before. did chg inv coolant pump after cleaning.

 

The buzzing sound is different from the position-learning issue described in this thread.

The buzzing sound is nothing but an inherent result of the way rapid pulses are used to position the throttle.

Mine makes the buzzing sound and always has. You'll be able to hear the buzzing sound in any Prius if you open the hood and listen for it.

I might not have any satisfying answer for why you had never noticed the buzzing sound from yours before. There could be various reasons why it could be slightly louder from one throttle body and slightly softer from another. There could be various reasons why its loudness could change slightly over time or with wear. There could be differences if you did work on the car that changed the tension or position of some of the rubber hoses, leaving them better conductors of sound.

But the bottom line is it's a sound that isn't going to go away. If you're sure it was once quieter, you could try drastic things like replacing the throttle body, and the new one might buzz more quietly. But then again, it might not.

 

fyi, buzzing sound has quieted, still there but not as loud.
unfortunately, i now have hv battery issue... always something....
thank you for wise words.