Need help to identify a plastic contain in right side fender well

someone else brought this up once, hmm... some kind of baffle or harmonic balancer kind of thingy?

 

Yep, its some sort of resonator chamber for the intake. Its not really necessary, mine has been without one for a year and a half.

 

This has been a good summer for the number of times the term "Helmholtz resonator" gets used in a forum.

The engine always sucks air in pulses, so there are always pressure waves in an intake. The Helmholtz resonator's job is to make sure the waves tend to increase the intake efficiency (air moving back toward the manifold at about the right time it's next needed) throughout the most important range of engine speeds, rather than being out of phase and decreasing it. That also tends to keep noise down (most of the wave energy is going into the engine rather than coming out the intake bell).

-Chap

 

Hmm, if it's dangling, you might check carefully whether its neck is still connected to the intake duct. Having it disconnected there magically changes it from a Helmholtz resonator into a random plastic jug.

-Chap

 

I think the ICE sounds better with it off.

 

can't find the part on toyota on line oem parts?

 

TOYOTA 17893-21030, RESONATOR, INTAKE AIR: Cart Part Info

 

I was thinking more about making sure the narrow neck at the top of the jug is still sealed into the intake duct, and there aren't any breaks anywhere that would make it leaky. Physics-wise, adding any new openings makes it a different resonator, possibly a poor match for the ICE.

I know it can seem weird to think that an empty jug hung off the intake is making any difference at all. I had a similar feeling once in a physics lab in college and I wrote a comment in the margin of my lab report, wondering why something made a difference when it didn't seem like it should. It came back with a note from the prof: "Are you planning to take Waves before you graduate? If not, You'll Never Know!"

Turned out I never did take Waves there, but eventually figured some of it out anyway ... what, did he think I'd never use a library?

-Chap

 

I think that the Atkinson-cycle engines used in the Prius tend to inherently produce more intake noise vs the Otto-cycle engines. Whatever the reason (local market noise standards, quiet passenger compartment, etc.) Toyota seems to have devoted lots of attention, as well as valuable under-the-hood space to this situation.
Bill