While trying to repair a noisy heat shield on my 2010 Gen 3, I noticed some strange pipes and what looks like some sort of actuator on the side of the exhaust between the cats and the main pipe going to the muffler. Looks like a resonator of some sort. Any idea what’s the function of it?
I really don’t know what it is. There is a hose connected to it that heads up towards the left side of the engine. I suppose that it could be some sort of preheater.
possible. try stuffing fire resistant materials like fiberglas in suspect areas and see if there's any change
oh cool ! didn't know about that ! now I understand why the Prius coolant temperature rises from cold to operating temp so quickly compared to other cars.
Thank you very much. Now I understand more about why/if the mysterious rattle seems to be coming from nowhere. After looking at the shop manual, perhaps it’s a loose flap or an interior part of the exhaust heat recovery system. Looks expensive. I’m not sure of what / where the No. 3 meter circuit plate is though. I like to understand more about the serviceability and what is involved with the repair or replacement of the EHRS? Your help is appreciated. How much is a shop book?
If you follow the link there's a diagram, showing some of the parts as replaceable, others not. I would be pretty surprised if the source of the noise really turned out to be anything besides one of the heat shields in that general neighborhood. Those are common sources of noises (I've got one myself I'm avoiding at the moment), and the EHRS isn't. The no. 3 meter circuit plate (suboptimal Japanese to English translation of printed circuit board) is the circuit board within the combination meter (in the dash) that controls the temperature warning light.
Well, after careful inspection and testing all other rattling possibilities, it appears to me that there is some damage to the heat recovery system. Specifically the actuator seems to stoved and out of alignment. It must of took a pretty good whack to bend it like that. Please see the attached pictures. What do you think?
I’m fearing that the rattle is internal. There doesn’t seem to be any other visible signs of damage though. Except the heat shield was beaten up a bit. There doesn’t seems to be no interference with the exhaust flow though.